CN115894533A - Polycyclic aromatic compound, material for organic device, organic electroluminescent element, display device, and lighting device - Google Patents

Polycyclic aromatic compound, material for organic device, organic electroluminescent element, display device, and lighting device Download PDF

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CN115894533A
CN115894533A CN202211155260.7A CN202211155260A CN115894533A CN 115894533 A CN115894533 A CN 115894533A CN 202211155260 A CN202211155260 A CN 202211155260A CN 115894533 A CN115894533 A CN 115894533A
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畠山琢次
王国防
川角亮介
近藤靖宏
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Kwansei Gakuin Educational Foundation
SK Materials JNC Co Ltd
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SK Materials JNC Co Ltd
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    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
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Abstract

The invention provides a polycyclic aromatic compound, a material for an organic device, an organic electroluminescent element, a display device, and a lighting device. Having a structure comprising the following formula (1)A polycyclic aromatic compound having one or two or more of the structural units shown in the formula (1) wherein the A, B and C rings are substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl rings, Y is > B-, > P (= O) -or > P (= S) -, and X is > C (-R) -, is useful as a material for organic devices such as organic electroluminescent elements X1 ) -, > N-or > Si (-R) X3 )‑，R X1 、R X3 Is a substituted or unsubstituted aryl group, etc., Z is > N-R Z2 Etc. R Z2 Is substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, etc., and L represents a linking group.
Figure DDA0003858194980000011

Description

Polycyclic aromatic compound, material for organic device, organic electroluminescent element, display device, and lighting device
Technical Field
The present invention relates to a polycyclic aromatic compound, a material for an organic device, an organic device such as an organic electroluminescent element, an organic field effect transistor, and an organic thin film solar cell using the same, a display device, and a lighting device.
Background
Conventionally, various studies have been made on display devices using light emitting elements that perform electroluminescence, in order to achieve power saving and reduction in thickness, and further, active studies have been made on organic electroluminescence elements including organic materials, in order to facilitate weight reduction and size increase. In particular, active studies have been made so far on the development of organic materials having light-emitting characteristics such as blue or green, which are one of the three primary colors of light, and on the development of organic materials having charge transport capabilities (having a possibility of becoming a semiconductor or a superconductor) including holes, electrons, and the like, both of high molecular compounds and low molecular compounds.
An organic Electroluminescence (EL) element has a structure including: a pair of electrodes including an anode and a cathode, and one or more layers which are disposed between the pair of electrodes and include an organic compound. The layer containing an organic compound includes a light-emitting layer, a charge transporting/injecting layer for transporting or injecting charges such as holes and electrons, and various organic materials suitable for the layers have been developed.
As a light-emitting material for a light-emitting layer, three materials, i.e., a fluorescent material, a phosphorescent material, and a Thermally Active Delayed Fluorescence (TADF) material, have been conventionally used. For example, as a fluorescent material, a material obtained by improving an azaborabenzene (azaborine) derivative has been reported (patent document 1), as a phosphorescent material, a noble metal complex having a multidentate ligand has been developed (patent document 2), and as a Thermally Active Delayed Fluorescence (TADF) material, a carbazole nitrile compound has been developed (non-patent document 1).
With respect to an element using any of the materials, in order to prevent energy leakage from a light-emitting layer or a peripheral layer associated with efficiency reduction, a material having high lowest excited singlet energy or lowest excited triplet energy is also used in an adjacent layer or a host of the light-emitting layer.
[ Prior art documents ]
[ patent document ]
[ patent document 1] International publication No. 2015/102118
[ patent document 2] Japanese patent laid-open No. 2014-239225
[ non-patent document ]
[ non-patent document 1] Nature (Nature) (492, 12 th 2012, 13 th 12 th)
Disclosure of Invention
[ problems to be solved by the invention ]
As described above, various materials have been developed as materials used for organic EL devices, but in order to increase the selection of materials for organic EL devices, it is desired to develop a material containing a compound different from the conventional one. Patent document 1 reports a polycyclic aromatic compound containing boron and an organic EL element using the compound, but in order to further improve element characteristics, a material for a light-emitting layer and a material for a peripheral layer are required which can improve light-emitting efficiency and element lifetime.
[ means for solving problems ]
The present inventors have made extensive studies to solve the above problems, and as a result, have succeeded in producing a novel polycyclic aromatic compound, and have found that the compound is effective as a material having high singlet energy and triplet energy. Further, the present inventors have found that an excellent organic EL element can be obtained by configuring an organic EL element by disposing a light-emitting layer, in which such a polycyclic aromatic compound is used as a host material or a material of a layer adjacent to the light-emitting layer and a compound having a triplet energy smaller than that is used as a dopant material, between a pair of electrodes, for example. That is, the present invention provides the following polycyclic aromatic compound, and a material for an organic device and the like containing the following polycyclic aromatic compound.
< 1 > a polycyclic aromatic compound having a structure containing one or more structural units represented by the following formula (1);
[ solution 1]
Figure BDA0003858194960000021
In the formula (1), the reaction mixture is,
ring A, ring B and ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,
y is > B-, > P (= O) -or > P (= S) -,
x is > C (-R) X1 ) -, > N-or > Si (-R) X3 )-，
R X1 And R X3 Each independently is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl,
z is > C (-R) Z1 ) 2 、＞N-R Z2 、＞O、＞Si(-R Z3 ) 2 Or is greater than the total mass of the particles,
R Z1 、R Z2 and R Z3 Each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, or together with the bonded elements and ring B or ring C, form a ring, wherein two R' s Z1 May be bonded to each other, and two R Z3 Can be bonded to each other and can be bonded to each other,
l is a shortest linking group having 1 to 4 atoms which links the ring A and the ring Y,
l may be bonded to the A ring by a linking group or a single bond,
at least one hydrogen in the structure may be substituted with deuterium, cyano or halogen.
< 2 > the polycyclic aromatic compound according to < 1 > wherein the structure comprises one of the structural units represented by formula (1).
< 3 > the polycyclic aromatic compound according to < 1 > or < 2 > wherein the A ring, the B ring and the C ring are each a substituted or unsubstituted benzene ring.
< 4 > the polycyclic aromatic compound according to any one of < 1 > to < 3 >, wherein L is > C (-R) L1 ) 2 、＞N-R L2 、＞O、＞Si(-R L3 ) 2 、＞S、＞C＝CR L1 2 、＞C＝NR L2 、＞C＝O、＞C＝S、-φ-、-φ-C(-R L1 ) 2 -、-φ-N(-R L2 )-、-φ-O-、-φ-Si(-R L3 ) 2 -、-φ-S-、-φ-C(＝CR L1 2 )-、-φ-C(＝NR L2 ) -, - φ -C (= O) -or- φ -C (= S) -,
R L1 、R L2 and R L3 Each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, two R's bonded to the same element L1 Or R L3 Can be bonded to each other, R L1 At least one of R L2 And R L3 May be bonded to at least one of the A ring or phi by a linking group or a single bond, respectively,
φ is a substituted or unsubstituted arylene or a substituted or unsubstituted heteroarylene, each having a bond between two adjacent ring-constituting atoms.
< 5 > the polycyclic aromatic compound according to < 4 > wherein L is > N-R L2 。
< 6 > the polycyclic aromatic compound according to < 4 > wherein L is 1,2-phenylene.
< 7 > the polycyclic aromatic compound according to any one of < 1 > to < 6 >, wherein X is > N-,
z is > N-R Z2 O, or S.
< 8 > the polycyclic aromatic compound according to any one of < 1 > to < 7 > wherein Y is B.
< 9 > the polycyclic aromatic compound according to < 1 > represented by any one of the following formulae,
[ solution 2]
Figure BDA0003858194960000031
< 10 > the polycyclic aromatic compound according to < 1 > represented by the following formula,
[ solution 3]
Figure BDA0003858194960000032
< 11 > a material for organic devices, comprising the polycyclic aromatic compound according to any one of < 1 > to < 10 >.
< 12 > an organic electroluminescent element having: a pair of electrodes including an anode and a cathode; and an organic layer disposed between the pair of electrodes, the organic layer containing the polycyclic aromatic compound according to any one of < 1 > to < 10 >.
< 13 > the organic electroluminescent element according to < 12 > wherein the organic layer is a light-emitting layer.
< 14 > the organic electroluminescent element according to < 13 > wherein the light-emitting layer contains the polycyclic aromatic compound as a host material, and a dopant material.
< 15 > the organic electroluminescent element according to < 12 > wherein the organic layer is an electron transport layer.
< 16 > the organic electroluminescent element according to < 12 > wherein the organic layer is a hole transport layer.
< 17 > a display device or a lighting device comprising the organic electroluminescent element according to any one of < 12 > to < 16 >.
[ Effect of the invention ]
According to a preferred embodiment of the present invention, an organic EL element having excellent quantum efficiency and element life can be provided by manufacturing an organic EL element using a novel polycyclic aromatic compound as, for example, a host material in a light-emitting layer, a component of the host material, or a component of a layer adjacent to the light-emitting layer.
Drawings
Fig. 1 is a schematic sectional view showing an organic EL element according to the present embodiment.
Fig. 2 is an energy level diagram showing the energy relationship among the host, the assist dopant, and the emissive dopant of a TAF element using a general fluorescent dopant.
Fig. 3 is a level diagram showing an example of an energy relationship among a host, an assist dopant, and an emitting dopant in an organic electroluminescent device according to an embodiment of the present invention.
[ description of symbols ]
100: organic electroluminescent element/organic EL element
101: substrate
102: anode
103: hole injection layer
104: hole transport layer
105: luminescent layer
106: electron transport layer
107: electron injection layer
108: and a cathode.
Detailed Description
The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments or specific examples, but the present invention is not limited to such embodiments. In the present specification, the numerical range expressed by the term "to" means a range including the numerical values described before and after the term "to" as the lower limit value and the upper limit value.
In the present specification, the "hydrogen atom (H)" may be referred to as "hydrogen" in the description of the structural formula. Similarly, "carbon atom (C)" is sometimes referred to as "carbon".
In the present specification, when "adjacent groups" are referred to, two groups to which adjacent two atoms (two atoms directly bonded through a covalent bond) are respectively bonded in the structural formula are referred to.
In the present specification, "Me" represents a methyl group, "Et" represents an ethyl group, "nBu" represents an n-butyl group (normal butyl group), "tBu" represents a tert-butyl group (tertiary butyl group), "iBu" represents an isobutyl group, "secBu" represents a sec-butyl group (secondary butyl group), "nPr" represents an n-propyl group (normal propyl group), "iPr" represents an isopropyl group, "tAm" represents a tert-pentyl group, "2EH" represents a 2-ethylhexyl group, "thoct" represents a tert-octyl group, "Ph" represents a phenyl group, "Mes" represents a mesityl group (2,4,6-trimethylphenyl group), "Tf" represents a trifluoromethanesulfonyl group, "TMS" represents a trimethylsilyl group, and "D" represents deuterium.
In this specification, an organic electroluminescent element is sometimes referred to as an organic EL element.
In the present specification, the chemical structure or the substituent may be represented by a carbon number, but the carbon number when the substituent is substituted in the chemical structure or when the substituent is further substituted on the substituent means the carbon number of each of the chemical structure or the substituent, and does not mean the total carbon number of the chemical structure and the substituent or the total carbon number of the substituent and the substituent. For example, the "substituent B having a carbon number Y substituted with the substituent a having a carbon number X" means that the "substituent a having a carbon number X" is substituted with the "substituent B having a carbon number Y, and the carbon number Y is not the total carbon number of the substituent a and the substituent B. For example, the "substituent B having a carbon number Y substituted by the substituent a" means that the substituent a "(not limited to a carbon number) is substituted on the" substituent B having a carbon number Y ", and the carbon number Y is not the total carbon number of the substituent a and the substituent B.
In the present specification, a substituent is sometimes substituted with a further substituent. For example, with respect to a particular substituent, it is sometimes stated as "substituted or unsubstituted". This means that the specified substituent is substituted or unsubstituted with at least one further substituent. In the same sense, it is sometimes referred to as "may be substituted". In the present specification, the specific substituent at this time is sometimes referred to as a "first substituent", and the further substituent is sometimes referred to as a "second substituent".
1. Polycyclic aromatic Compound of the present invention
The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure containing one or more than two of the structural units represented by the formula (1).
[ solution 4]
Figure BDA0003858194960000051
The present inventors have found that the polycyclic aromatic compound of the present invention in which aromatic rings are connected by hetero elements such as boron, phosphorus, oxygen, nitrogen, and sulfur has a large Highest Occupied Molecular Orbital (HOMO) -Lowest Unoccupied Molecular Orbital (LUMO) gap (band gap Eg in the thin film) and a high triplet energy. The reason is considered to be that: the 6-membered ring containing a hetero element has low aromaticity, and therefore, the reduction of the HOMO-LUMO gap accompanying the expansion of the conjugated system is suppressed; the expansion of the conjugated system is suppressed by utilizing the intramolecular strain, thereby obtaining a large HOMO-LUMO gap.
The heterocyclic aromatic compound containing a hetero element of the present invention is also effective as a material having high triplet energy as a host compound for phosphorescent organic EL devices or thermally active fluorescence-delayed organic EL devices, an electron blocking layer (electron blocking layer) or a hole blocking layer (hole blocking layer) adjacent to a light-emitting layer, and an electron transporting layer or a hole transporting layer. Further, since the energy of HOMO and LUMO can be arbitrarily changed by introducing a substituent into these polycyclic aromatic compounds, the ionization potential or electron affinity can be optimized according to the peripheral materials.
< Ring Structure of structural Unit represented by formula (1) >
In the formula (1), "a" to "C" in the circle are symbols representing ring structures represented by the circle.
Ring a, ring B and ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. The rings A to C each have a divalent group having a bond to two adjacent carbons formed on the aryl ring or the heteroaryl ring in the structure.
Among the substituted or unsubstituted aryl rings or substituted or unsubstituted heteroaryl rings in the a, B and C rings of the structural unit represented by formula (1), the substituent referred to as "substituted or unsubstituted (substituted or unsubstituted)" is preferably at least one substituent selected from substituent group Z described later.
The polycyclic aromatic compound of the present invention has a first XY-containing ring structure composed of two carbons in the a ring, X, Y and L, and a second XY-containing ring structure composed of two carbons in the B ring, Z and two carbons in the C ring, in the molecule. The second "XY-containing ring structure" is a 7-membered ring. The compound of the present invention has a "condensed bicyclic structure" formed of a first "XY-ring-containing structure" and a second "XY-ring-containing structure" after condensation.
[ solution 5]
Figure BDA0003858194960000061
Here, the "XY-containing ring structure" in the formula (1) is a ring structure including X and Y, the "first XY-containing ring structure" is formed of two carbons in the a ring, which are bonded to X and L, respectively, and located at the o-position from each other, X, Y and L, and the "second XY-containing ring structure" is formed of two carbons in the B ring, which are bonded to X and Z, respectively, and located at the o-position from each other, two carbons in the C ring, which are bonded to Y and Z, respectively, and located at the o-position from each other, X, Y and Z. Similarly, in formula (2), the "XY-ring-containing structure" is a ring structure including X and Y, and the "first XY-ring-containing structure" is formed of two carbons located at the o-position in the a-ring, X, Y and L, and the "second XY-ring-containing structure" is formed of two carbons located at the o-position in the b-ring, two carbons located at the o-position in the c-ring, X, Y and Z.
The "condensed bicyclic structure" as used herein means a structure obtained by condensing two saturated hydrocarbon rings including Y and X, i.e., "a first XY-ring-containing structure" and "a second XY-ring-containing structure" in the formula (1). The "condensed bicyclic structure" further shares a bond with the A ring to the C ring in any ring. That is, the A ring to the C ring are condensed with the "condensed bicyclic structure". As described above, the polycyclic aromatic compound of the present invention has a polycyclic structure in which at least five rings are condensed.
For example, each of the rings A to C may independently have a "6-membered ring having a bond in common with the condensed bicyclic structure", that is, a 6-membered ring condensed to the condensed bicyclic structure (preferably, a benzene ring C). The expression "aryl ring or heteroaryl ring having the 6-membered ring" (as a ring a) "means that the ring a is formed only from the 6-membered ring, or that another ring is further condensed with the 6-membered ring so as to include the 6-membered ring, or the like. In other words, the "aryl ring or heteroaryl ring having 6-membered rings (as A ring)" as used herein means that 6-membered rings constituting all or part of A ring are condensed to a condensed bicyclic structure. The same explanation applies to the "B ring" and the "C ring", and the same explanation applies to the "5-membered ring".
The structure in which each of the rings A to C of the formula (1) has a benzene ring condensed in a condensed bicyclic structure can be represented by the following formula (2), and the structural unit represented by the formula (2) is a preferable example of the structural unit represented by the formula (1).
[ solution 6]
Figure BDA0003858194960000071
The ring A, ring B and ring C in the formula (1) correspond to the ring a and the substituent R in the formula (2) respectively a B ring and substituent R thereof b And c ring and its substituent R c . As described above, the formula (2) corresponds to the following structure: the rings A to C in the formula (1) have a 6-membered ring as a ring directly condensed with the condensed bicyclic structure. "having" a 6-membered ring is due to: as described later, for example, with respect to the a ring which is a 6-membered ring, four substituents R thereof a The adjacent groups in (1) may be bonded to each other to form a ring, and then another ring may be further condensed with a ring a which is a 6-membered ring. In this sense, the upper case of A to C represents the rings of formula (1), while the lower case of a to C represents the rings of formula (2).
R in the formula (2) a 、R b And R c Each independently hydrogen or a substituent. The substituent includes at least one substituent selected from substituent group Z described later.
The substituents R of the ring a, ring b and ring c in the formula (2) a A substituent R b And a substituent R c The adjacent groups in (a) may be bonded to each other and form an aryl ring or a heteroaryl ring together with the a-ring, the b-ring and the c-ring, respectively, and the formed ring may be substituted with at least one substituent selected from substituent group Z described later.
Therefore, the polycyclic aromatic compound of the formula (2) changes the ring structure constituting the compound, as shown in the following formula (2-fr), for example, depending on the mutual bonding form of the substituents in the a-ring to the c-ring. The ring A 'and the ring B' in the following formula correspond to the ring A and the ring B in the formula (1), respectively. In addition, the c-ring can be similarly changed.
[ solution 7]
Figure BDA0003858194960000081
When the formula (2) is used for illustration, the ring A' in the formula (2-fr) represents a plurality of substituents R a An aryl ring or a heteroaryl ring (which may also be referred to as a condensed ring in which other ring structures are condensed to the a ring) in which adjacent groups in (b) are bonded to each other and form together with the a ring. Similarly, the B' ring represents a plurality of substituents R b The adjacent groups in (b) are bonded to each other to form an aryl ring or a heteroaryl ring together with the b ring (may also be referred to as a condensed ring in which other ring structures are condensed to the b ring).
The formula (2-fr) has an a 'ring or a B' ring formed by condensation of a benzene ring, such as a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring, or a benzothiophene ring, with the condensed ring a 'or the condensed ring B' being a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring, or a dibenzothiophene ring, respectively.
A more specific example of formula (2-fr) is shown below.
[ solution 8]
Figure BDA0003858194960000082
The above-mentioned formulas (2-fr-ex) are specific examples of the formulas (2-fr) respectively, and are adjacent two R in the a-rings of the formulas (2) and (2) a Two adjacent R's bonded to and taken together with the a-ring (benzene ring) to form a heteroaryl ring (dibenzofuran ring) and the b-ring b Bonded to and taken together with the b-ring (benzene ring) to form an aryl ring (naphthalene ring). The formed rings each have a 6-membered ring (benzene ring a or benzene ring b) having a bond in common with the condensed bicyclic structure. Any substituents for heteroaryl ring A 'and aryl ring B' (ring A and ring B of formula (1)) other than R a And R b In addition to the above, n is represented by R, and the lower limit of n is 0,n, and the upper limit thereof is the maximum number (4) that can be substituted. Note that these descriptions are also applicable to all forms other than the specific examples, for example, a case where the c-ring is changed or a case where another aryl ring or heteroaryl ring is formed.
Any of the rings "C (-R) =" (where R is R) in the a ring, the b ring, and the C ring in the structural unit represented by formula (2) a 、R b Or R c ) The structural unit represented by the formula substituted with "-N =" may be listed as a preferred example of the structural unit represented by the formula (1). Examples of the ring in which "— C (-R) =" is substituted with "— N =" in the a-ring to C-ring (benzene ring) of formula (2) include a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, and other nitrogen-containing heteroaryl rings. Examples in which the a-ring moiety of formula (2) is a nitrogen-containing heteroaryl ring are shown below.
[ solution 9]
Figure BDA0003858194960000091
In addition, an adjacent group (adjacent R) present in a ring in which "— C (-R) =" is substituted with "— N =" in the a ring, the b ring, and the C ring (benzene ring) a Adjacent R b Or adjacent R c ) Structures that bond to and form, together with the ring, a heteroaryl ring (in the formula, a quinoline ring) are also preferred. The case where the formed ring may be further substituted (hereinafter represented by n R) is as described above. The ring a of formula (2) is an example of the above ring.
[ solution 10]
Figure BDA0003858194960000092
In addition, the following examples are given.
[ solution 11]
Figure BDA0003858194960000101
The same applies to the case where the other site of the a ring in the formula (2) is substituted with "-N =", or the case where the b ring or c ring is changed.
Any of the a-ring to C-ring in the structural unit represented by the formula (2) — C (-R) = C (-R) - "(here, R is R) a 、R b And R c ) Is substituted with "-N (-R) -", "-O-", "-S-", "-C (-R) 2 -”、“-Si(-R) 2 The structural unit represented by the formula (- ") or" -Se- "is also listed as a preferable example of the structural unit represented by the formula (1). The "C (-R) = C (-R) -" in the a-ring to C-ring (benzene ring) of the formula (2) is substituted with "-N (-R) -", or "-O-", "-S-", "-C (-R) 2 -”、“-Si(-R) 2 Examples of the ring formed of- ", or" -Se- "include a pyrrole ring, a furan ring, a thiophene ring, another nitrogen/oxygen/sulfur-containing heteroaryl ring (5-membered ring), or another nitrogen/oxygen/sulfur-containing aryl ring (5-membered ring). The R of the "-N (-R) -", "-C (-R) 2 R of- "and" -Si (-R) 2 R of-is hydrogen, aryl, heteroaryl, alkyl, or cycloalkyl, at least one of which may be substituted with alkyl or cycloalkyl.
The ring a portion of formula (2) is an example of the above-described ring.
[ solution 12]
Figure BDA0003858194960000102
In addition, the first and second substrates are, the "-C (-R) = C (-R) -" in the a-C ring (benzene ring) is substituted with "-N (-R) -", "-O-", "-S-", "-C (-R) 2 -”、“-Si(-R) 2 - ", or" -Se- "to an adjacent group (adjacent R) a Adjacent R b Or adjacent R c ) The structure bonded to and forming a heteroaryl ring (a ring such as an indole ring, a benzofuran ring, or a benzothiophene ring) together with the ring is also preferable.
An example of such a ring is shown below for the a-ring portion of formula (2).
[ solution 13]
Figure BDA0003858194960000103
In addition, the following examples are given.
[ solution 14]
Figure BDA0003858194960000111
The other part of the a-ring of the formula (2) is substituted with "-N (-R) -", "-O-", "-S-", "-C (-R) 2 -”、“-Si(-R) 2 The same applies to the case of- ", or" -Se- ", or the case where the b-ring and the c-ring are changed.
Description of < L >
L is a divalent linking group, and the shortest number of atoms between two bonding positions is 1 to 4. That is, in formula (1), L is the shortest linking group having 1 to 4 atoms that links the ring A and the ring Y. Accordingly, the number of atoms constituting the first XY ring-containing structure is 5 to 8. The shortest number of atoms connecting the ring a and the ring Y is preferably 1 to 3, and more preferably 1 or 2.
L is preferably > C (-R) L1 ) 2 、＞N-R L2 、＞O、＞Si(-R L3 ) 2 、＞S、＞C＝CR L1 2 、＞C＝NR L2 、＞C＝O、＞C＝S、-φ-、-φ-C(-R L1 ) 2 -、-φ-N(-R L2 )-、-φ-O-、-φ-Si(-R L3 ) 2 -、-φ-S-、-φ-C(＝CR L1 2 )-、-φ-C(＝NR L2 ) -, - φ -C (= O) -and φ -C (= S) -. In addition, in the above, any one of the bond bonds is used to bond with the a ring and another bond is used to bond with the Y ring, but any bond may be used to bond with any one of the bond bonds. Here, R L1 、R L2 、R L3 Each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, two R's bonded to the same element L1 Or R L3 Can be bonded to each other, R L1 At least one of R L2 And R L3 May be bonded to at least one of the A ring or phi by a linking group or a single bond, respectively. Phi is a substituted or unsubstituted arylene or substituted or unsubstituted heteroarylene, phi sets the adjacent two ring-constituting atoms to the bonding position.
L is preferably > N-R L2 、＞O、＞S、-φ-、-φ-N(-R L2 ) -, -O-or-S-, in the formula (2), L is > N-R L2 、＞O、＞S、-φ-、-φ-N(-R L1 ) The structures of the- (O) -, -phi-O-or-phi-S-are respectively represented by a formula (2-a), a formula (2-x), a formula (2-t), a formula (2-f) the formula (2-af), the formula (2-xf), the formula (2-tf), the formula (2-fa), the formula (2-fx), and the formula (2-ft).
[ chemical 15]
Figure BDA0003858194960000121
Phi in L is a substituted or unsubstituted arylene or a substituted or unsubstituted heteroarylene. The arylene and heteroarylene groups in phi each have a bond on two adjacent ring-constituting atoms.
In the definition of φ, the substituent referred to as "substituted or unsubstituted" is preferably at least one substituent selected from the substituent group Z described later.
φ is preferably unsubstituted arylene or unsubstituted heteroarylene, more preferably unsubstituted 1,2-phenylene. Examples of the structural unit represented by formula (2) in which φ is an unsubstituted arylene group or an unsubstituted heteroarylene group are shown below.
[ solution 16]
Figure BDA0003858194960000131
< description of Y >
Y is independently > B-, > P (= O) -, > P (= S) -, > Al-, > Ga-, > As-, > C (-R) -, > Si (-R) -, or > Ge (-R) -, wherein R of > C (-R) -, > R of Si (-R) -, and R of > Ge (-R) -are independently aryl which may be substituted, heteroaryl which may be substituted, alkyl which may be substituted, or cycloalkyl which may be substituted. Y represents a partial structure having three bonds on one atom, and for example, three bonds represented by > P (= O) -, > P (= S) -are located on P (phosphorus atom). Y is preferably > B-, > P (= O) -, or > P (= S) -, more preferably > B-.
Description of < X >
X in the formula (1) is respectively and independently > N-, > C (-R) X1 ) Or > Si (-R) X3 )，R X1 And R X3 Each independently is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl. At R X1 And R X3 In the definition of (1), as the substituent referred to as "substituted or unsubstituted", there may be mentioned at least one substituent selected from the substituent group Z described later.
As X, it is preferably > N-or > C (-R) X1 ) More preferably > N-.
Description of < Z >
Z in the formula (1) is > C (-R) Z1 ) 2 、＞N-R Z2 、＞O、＞Si(-R Z3 ) 2 Or > S. Here, R Z1 、R Z2 、R Z3 Each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, or together with the elements bonded and the rings of ring B or ring C, form a ring. Wherein two R are Z1 And two R Z3 Can be bonded to each other. As R Z1 、R Z2 、R Z3 The structure forming a ring together with the element (C, N or Si) to be bonded and the ring of the B or C ring includes R through any of the groups (in particular, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl) Z1 、R Z2 、R Z3 The bonding group (linking group or single bond) to the B ring or the C ring.
Examples of the linking group include: -CH 2 -CH 2 -、-CHR-CHR-、-CR 2 -CR 2 -、-CH＝CH-、-CR＝CR-、-C≡C-、-N(-R)-、-O-、-S-、-C(-R) 2 -、-Si(-R) 2 -, or-Se-. Furthermore, R, -CR of said-CHR- 2 -CR 2 R of-R, -CR = R of CR, -R of N (-R) -, -C (-R) 2 R of (A-C)and-Si (-R) 2 Each R of (A) is independently hydrogen, aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl, at least one of which may be substituted with alkyl or cycloalkyl. In addition, two adjacent R groups may form a ring with each other to form a cycloalkylene group, an arylene group, and a heteroarylene group.
As a bonding group, a group having a group of a bond, preferably a single bond, a linking group of-CR = CR-, -N (-R) -, -O-, -S-, -C (-R) 2 -、-Si(-R) 2 -, and-Se-, more preferably a single bond, a linking group of-CR = CR-, -N (-R) -, -O-, -S-, and-C (-R) 2 <xnotran> -, , -CR = CR-, -N (-R) -, -O-, -S-, . </xnotran>
R Z2 And R Z3 The position to which the B ring or the C ring is bonded is not particularly limited as long as it is a position capable of bonding, and it is preferably a position bonded to the adjacent position (2 position) based on the Z bonding position (1 position).
Shown below is > N-R Z2 R of (A) Z2 And a B ring or a C ring as a benzene ring.
[ chemical formula 17]
Figure BDA0003858194960000151
Z is preferably > N-R Z2 O, or S.
< bonding of rings to each other >
In formula (1), two rings directly bonded to each other by a single bond and two rings bonded to a common atom may be further bonded by an additional single bond or a linking group (these are also collectively referred to as a bonding group), respectively. Specifically, the following structures can be mentioned.
The A ring and the B ring are further bonded to each other in addition to X through a bonding group. (wherein the A ring and the B ring are bonded to a common atom in X)
When L contains- φ -bonded directly to the A ring, φ and A ring are bonded through additional bonding groups.
When L contains- φ -bonded directly to Y, φ and C ring are bonded through additional bonding groups.
When L comprises-N (-R) directly bonded to the A ring L1 ) When is, R L1 (R L1 Substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl) is bonded to the a ring through an additional bonding group.
L is- φ -N (-R) L1 ) Phi and R of-time L1 (R L1 Substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl) is bonded through an additional bonding group.
For example, in the formula (2), R bonded to a carbon atom adjacent to the carbon atom bonded to X a And R b Can bond with each other to form a single bond or a linking group. In addition, in the formula (2), R bonded to a carbon atom adjacent to the carbon atom bonded to Z b And R c Can bond with each other to form a single bond or a linking group.
In addition, in the formulae (2-a) and (2-af), the a-ring and the φ ring may be bonded through an additional bonding group. In the formulae (2-af), (2-xf) and (2-tf), the c-ring and the φ -ring may be bonded via additional bonding groups. In the formulae (2-fa), (2-fx) and (2-ft), when R is L1 When it is substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl or substituted or unsubstituted cycloalkyl, R L1 And the φ ring may be bonded through additional bonding groups. The a ring and φ ring in the formula (2-f), formula (2-fa), formula (2-fx), and formula (2-ft) may be bonded through an additional bonding group.
Examples of the linking group include: -CH 2 -CH 2 -、-CHR-CHR-、-CR 2 -CR 2 -、-CH＝CH-、-CR＝CR-、-C≡C-、-N(-R)-、-O-、-S-、-C(-R) 2 -、-Si(-R) 2 -, or-Se-. Furthermore, R, -CR of said-CHR- 2 -CR 2 R of-R, -CR = R of CR, -R of N (-R) -, -C (-R) 2 R of-and-Si (-R) 2 R of-is each independently hydrogen, aryl, heteroaryl, alkyl, alkeneAnd R is optionally substituted with alkyl or cycloalkyl. In addition, two adjacent R's may form a ring with each other to form a cycloalkylene, an arylene, and a heteroarylene.
As a bonding group, a group having a group of a bond, preferably a single bond, a linking group of-CR = CR-, -N (-R) -, -O-, -S-, -C (-R) 2 -、-Si(-R) 2 -, and-Se-, more preferably a single bond, a linking group of-CR = CR-) -N (-R) -, -O-, -S-, and-C (-R) 2 <xnotran> -, , -CR = CR-, -N (-R) -, -O-, -S-, . </xnotran>
The position at which two rings are bonded via a bonding group is not particularly limited as long as it is a position capable of bonding, and it is preferable that the two rings are bonded at the most adjacent positions, and for example, in the two rings bonded via N, it is preferable that the two rings are further bonded at positions adjacent to each other (2-position) based on the bonding position (1-position) of "N" in each ring (see the structural formula of formula (1)).
< case where two radicals bonded to the same atom are bonded to each other >
＞C(-R Z1 ) 2 、＞Si(-R Z3 ) 2 、-C(-R) 2 -、-Si(-R) 2 Two radicals (two R) of (a) or (b) bound to the same atom Z1 Two R Z3 And the other two R) may be bonded to each other to form a ring. The bond may be a single bond or a linking group (these are also collectively referred to as a bonding group), and examples of the linking group include: -CH 2 -CH 2 -、-CHR-CHR-、-CR 2 -CR 2 -、-CH＝CH-、-CR＝CR-、-C≡C-、-N(-R)-、-O-、-S-、-C(-R) 2 -、-Si(-R) 2 Examples of-Se-or-Se-include the following structures. Furthermore, R, -CR of said-CHR- 2 -CR 2 R of-R, -CR = R of CR, -R of N (-R) -, -C (-R) 2 R of-and-Si (-R) 2 R of-is each independently hydrogen, aryl which may be substituted by alkyl or cycloalkyl, heteroaryl which may be substituted by alkyl or cycloalkyl, alkyl which may be substituted by cycloalkyl, alkenyl which may be substituted by alkyl or cycloalkyl, alkynyl which may be substituted by alkyl or cycloalkylOr cycloalkyl which may be substituted by alkyl or cycloalkyl. In addition, two adjacent R's may form a ring with each other to form a cycloalkylene, an arylene, and a heteroarylene.
[ solution 18]
Figure BDA0003858194960000171
As a group of the bond (S), preferably a single bond, a linking group of-CR = CR-) -N (-R) -, -O-, -S-, -C (-R) 2 -、-Si(-R) 2 -, and-Se-, more preferably a single bond, a linking group of-CR = CR-) -N (-R) -, -O-, -S-, and-C (-R) 2 <xnotran> -, , -CR = CR-, -N (-R) -, -O-, -S-, . </xnotran>
The position at which two R groups are bonded via a bonding group is not particularly limited as long as it is a position capable of bonding, and it is preferable that the two R groups are bonded at the most adjacent positions, and for example, in the case where the two R groups are phenyl groups, it is preferable that the two R groups are bonded at positions adjacent to each other (2-position) based on the bonding position (1-position) of "C" or "Si" in the phenyl group (see the structural formula).
< detailed description of the rings and substituents >
The details of the ring and the substituent described in the present specification are described below.
The "aryl ring" is, for example, an aryl ring having 6 to 30 carbon atoms, and is preferably an aryl ring having 6 to 20 carbon atoms, an aryl ring having 6 to 16 carbon atoms, an aryl ring having 6 to 12 carbon atoms, an aryl ring having 6 to 10 carbon atoms or the like.
Specific "aryl rings" are for example: a benzene ring of a monocyclic system, a naphthalene ring of a condensed bicyclic system, an acenaphthene ring, a fluorene ring, a phenalene ring, or a phenanthrene ring, an anthracene ring of a condensed tricyclic system, a triphenylene ring, a pyrene ring, or a quaterpene ring of a condensed tetracyclic system, or a perylene ring or a pentacene ring of a condensed pentacyclic system, and the like.
The "heteroaryl ring" is, for example, a heteroaryl ring having 2 to 30 carbon atoms, preferably a heteroaryl ring having 2 to 25 carbon atoms, a heteroaryl ring having 2 to 20 carbon atoms, a heteroaryl ring having 2 to 15 carbon atoms, or a heteroaryl ring having 2 to 10 carbon atoms. The "heteroaryl group" is, for example, a heterocyclic ring or the like containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen as ring-constituting atoms in addition to carbon.
Specific "heteroaryl rings" are for example: pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, oxadiazole ring (furazan ring and the like), thiadiazole ring, triazole ring, tetrazole ring, pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phenanthroline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiin ring, phenoxazine ring, naphthoxazine ring, phenanthridine ring, etc phenothiazine ring, phenazine ring, phenazinosiline (phenazaline) ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, naphthobenzofuran ring, thiophene ring, benzothiophene ring, isobenzothiophene ring, dibenzothiophene ring, naphthobenzothiophene ring, benzophosphole ring, dibenzophosphole ring, benzophosphole oxide ring, dibenzophosphole oxide ring, thianthrene ring, indolocarbazole ring, benzindolocarbazole ring, dibenzoindolocarbazole ring, imidazoline ring, or oxazoline ring, and the like.
In the present specification, substituent group Z includes:
aryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
diarylamino groups (two aryl groups may be bonded to each other via a linking group), which may be substituted with at least one group selected from the group consisting of aryl groups, heteroaryl groups, alkyl groups, and cycloalkyl groups;
diheteroarylamino (two heteroaryl groups may be bonded to each other via a linking group), which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
arylheteroarylamino (aryl and heteroaryl may be bonded to each other via a linking group), which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
a diarylboron group (two aryl groups may be bonded via a single bond or a linking group), which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl;
an alkyl group which may be substituted with at least one group selected from the group consisting of an aryl group, a heteroaryl group and a cycloalkyl group;
cycloalkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;
aryloxy group which may be substituted with at least one group selected from the group consisting of aryl group, heteroaryl group, alkyl group and cycloalkyl group; and
substituted silane groups.
The aryl group as the second substituent in each group of the substituent group Z may be further substituted with an aryl group, a heteroaryl group, an alkyl group, or a cycloalkyl group, and likewise, the heteroaryl group as the second substituent may be substituted with an aryl group, a heteroaryl group, an alkyl group, or a cycloalkyl group.
In the present specification, "aryl" is, for example, an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aryl group having 6 to 10 carbon atoms, or the like.
Specific "aryl" groups are for example: a monocyclic phenyl group, a bicyclic biphenyl group (2-biphenyl group, 3-biphenyl group, or 4-biphenyl group), a condensed bicyclic naphthyl group (1-naphthyl group or 2-naphthyl group), a tricyclic terphenyl group (m-terphenyl-2 ' -yl, m-terphenyl-4 ' -yl, m-terphenyl-5 ' -yl, o-terphenyl-3 ' -yl, o-terphenyl-4 ' -yl, p-terphenyl-2 ' -yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p-terphenyl-4-yl), an acenaphthene- (1-, 3-, 4-, or 5-) group, a fluorene- (1-, 2-, 3-, 4-, or 9-) group, a phenalene- (1-or 2-) group, a phenanthrene- (1-, 2-, 3-, 4-, or 9-) group, or an anthracene- (1-, 2-, or 9-) group which is a condensed tricyclic system, a tetrabiphenyl group (5 ' -phenyl-m-terphenyl-2-yl, 5' -phenyl-m-terphenyl-3-yl, 5' -phenyl-m-terphenyl-4-yl group, a tetrakis system, or meta-tetrabiphenyl group) which is a triphenylene- (1-or 2-) group, a pyrene- (1-, 2-, or 4-) group, or a tetracene- (1-, 2-, or 5-) group of a condensed four-ring system, or a perylene- (1-, 2-, or 3-) group, or a pentacene- (1-, 2-, 5-, or 6-) group of a condensed five-ring system, and the like. In addition, a monovalent group of spirofluorene, etc., may be mentioned.
Further, the aryl group as the second substituent also includes: the aryl group may be substituted with at least one group selected from the group consisting of an aryl group such as a phenyl group (specifically, the group mentioned above), an alkyl group such as a methyl group (specifically, the group mentioned below), and a cycloalkyl group such as a cyclohexyl group or an adamantyl group (specifically, the group mentioned below).
Examples thereof include a group in which the 9-position of the fluorenyl group as the second substituent is substituted with an aryl group such as a phenyl group, an alkyl group such as a methyl group, or a cycloalkyl group such as a cyclohexyl group or an adamantyl group.
The "arylene group" is, for example, an arylene group having 6 to 30 carbon atoms, preferably an arylene group having 6 to 20 carbon atoms, an arylene group having 6 to 16 carbon atoms, an arylene group having 6 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, or the like.
Specific examples of the "arylene group" include divalent groups obtained by removing one hydrogen from the above-mentioned "aryl group" (monovalent group).
The "heteroaryl group" is, for example, a heteroaryl group having 2 to 30 carbon atoms, preferably a heteroaryl group having 2 to 25 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms. The "heteroaryl group" contains 1 or more, preferably 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen and the like as ring-constituting atoms in addition to carbon.
As specific "heteroaryl", for example: pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathiin, phenoxazinyl, phenothiazinyl, phenazinyl, phenazosilyl (phenazasilinyl), indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thiophenyl, dibenzophosphoryl, benzophosphole, cyclopentadienyl of a benzophosphole ring, phosphole-substituted, dibenzocarboxanyl, indolinyl, benzoxazolyl, or the like. In addition to these, there may be mentioned: spiro [ fluorene-9,9' -xanthene ], spiro [ silafluorene ] and benzoselenophene.
In addition, the heteroaryl group as the second substituent also includes: the heteroaryl group has a structure in which it is substituted with at least one group selected from the group consisting of an aryl group such as a phenyl group (specifically, the group mentioned above), an alkyl group such as a methyl group (specifically, the group mentioned below), and a cycloalkyl group such as a cyclohexyl group or an adamantyl group (specifically, the group mentioned below).
Examples thereof include: the carbazolyl group as the second substituent is a group substituted at the 9-position with an aryl group such as a phenyl group, an alkyl group such as a methyl group, or a cycloalkyl group such as a cyclohexyl group or an adamantyl group. In addition, a group in which a nitrogen-containing heteroaryl group such as a pyridyl group, a pyrimidinyl group, a triazinyl group, or a carbazolyl group is further substituted with a phenyl group, a biphenyl group, or the like is also included in the heteroaryl group as the second substituent.
The "heteroarylene group" is, for example, a heteroarylene group having 2 to 30 carbon atoms, preferably a heteroarylene group having 2 to 25 carbon atoms, a heteroarylene group having 2 to 20 carbon atoms, a heteroarylene group having 2 to 15 carbon atoms, a heteroarylene group having 2 to 10 carbon atoms, or the like. The "heteroarylene group" is, for example, a divalent group such as a heterocyclic ring containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen as ring-constituting atoms in addition to carbon.
Specific examples of the "heteroarylene group" include a divalent group obtained by removing one hydrogen from the "heteroaryl group" (monovalent group).
"diarylamino" is an amino group substituted with two aryl groups, and the description of the "aryl" can be cited for details of the aryl group.
"Diheteroarylamino" is an amino group substituted with two heteroaryl groups, and reference is made to the description of "heteroaryl" for details of such heteroaryl groups.
"Arylheteroarylamino" is an amino group substituted with aryl and heteroaryl groups, and the details of the aryl and heteroaryl groups can be found in the description of the "aryl" and "heteroaryl".
Two aryl groups of the diarylamino group as the first substituent may be bonded to each other via a linking group, two heteroaryl groups of the diheteroarylamino group as the first substituent may be bonded to each other via a linking group, and an aryl group and a heteroaryl group of the arylheteroarylamino group as the first substituent may be bonded to each other via a linking group. Here, the description "bonded via a linking group" is as follows, and for example, two phenyl groups each representing a diphenylamino group form a bond via a linking group. In addition, the description also applies to diheteroarylamino and arylheteroarylamino groups formed from aryl or heteroaryl groups.
[ formula 19]
Figure BDA0003858194960000201
Specific examples of the linking group include: > O, > N-R X 、＞C(-R X ) 2 、＞Si(-R X ) 2 、＞S、＞CO、＞CS、＞SO、＞SO 2 And > Se. R is X Each independently being an alkyl, cycloalkyl, aryl or heteroaryl groupThese may be substituted with alkyl, cycloalkyl, aryl or heteroaryl groups. Additionally, > C (-R) X ) 2 、＞Si(-R X ) 2 R in (1) X Can be via a single bond or a linking group X Y Bonded to form a ring. As X Y Mention may be made of > O, > N-R Y 、＞C(-R Y ) 2 、＞Si(-R Y ) 2 、＞S、＞CO、＞CS、＞SO、＞SO 2 And > Se, R Y Each independently being an alkyl, cycloalkyl, aryl or heteroaryl group, which may be substituted by an alkyl, cycloalkyl, aryl or heteroaryl group. Wherein, in X Y Is > C (-R) Y ) 2 And > Si (-R) Y ) 2 In the case of (2), two R Y No further ring formation occurs due to the bonding. Further, as the linking group, an alkenylene group may be mentioned. Any hydrogen of the alkenylene group may independently pass through R X Substituted, R X Independently from each other, alkyl, cycloalkyl, substituted silyl, aryl and heteroaryl, which may be substituted with alkyl, cycloalkyl, substituted silyl, aryl.
In addition, in the case where only "diarylamino group", "diheteroarylamino group", or "arylheteroarylamino group" is described in the present specification, unless otherwise specified, the description is made such that "two aryl groups of diarylamino group may be bonded to each other via a linking group", "two heteroaryl groups of diarylamino group may be bonded to each other via a linking group", and "aryl and heteroaryl groups of arylheteroarylamino group may be bonded to each other via a linking group", respectively.
A "diarylboron group" is a boron group in which two aryl groups are substituted, and the description of the "aryl group" can be cited for details of the aryl group. In addition, the two aryl groups may be linked via a single bond or a linking group (e.g., -CH = CH-, -CR = CR-, -C ≡ C-, > N-R, > O, > S, > C (-R) 2 、＞Si(-R) 2 Or > Se). Here, the-CR = R of CR-, > R of N-R, > C (-R) 2 R of (a), and R > Si (-R) is aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxyAt least one hydrogen in R may be further substituted with aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. In addition, two adjacent R groups may form a ring with each other to form a cycloalkylene group, an arylene group, and a heteroarylene group. As for details of the substituents listed here, the descriptions of "aryl", "arylene", "heteroaryl", "heteroarylene", and "diarylamino" and the descriptions of "alkyl", "alkenyl", "alkynyl", "cycloalkyl", "cycloalkylene", "alkoxy", and "aryloxy" described later can be cited. In the present specification, when only the "diarylboron group" is described, unless otherwise specified, the description is made such that two aryl groups to which the "diarylboron group is added may be bonded to each other via a single bond or a linking group.
The "alkyl group" may be either a straight chain or branched chain, and is, for example, a straight-chain alkyl group having 1 to 24 carbon atoms or a branched chain alkyl group having 3 to 24 carbon atoms, preferably an alkyl group having 1 to 18 carbon atoms (a branched chain alkyl group having 3 to 18 carbon atoms), an alkyl group having 1 to 12 carbon atoms (a branched chain alkyl group having 3 to 12 carbon atoms), an alkyl group having 1 to 6 carbon atoms (a branched chain alkyl group having 3 to 6 carbon atoms), an alkyl group having 1 to 5 carbon atoms (a branched chain alkyl group having 3 to 5 carbon atoms), an alkyl group having 1 to 4 carbon atoms (a branched chain alkyl group having 3 to 4 carbon atoms), and the like.
Specific "alkyl" groups are for example: <xnotran> , , , ,1- -1- , 4984 zxft 4984- , 5272 zxft 5272- , 7945 zxft 7945- ,1- -3272 zxft 3272- , , , , ,2- , 3424 zxft 3424- , 3535 zxft 3535- , 3584 zxft 3584- ,1- -1- ,1- -1- , 4284 zxft 4284- ,1- -5325 zxft 5325- , , , , (t-pentyl) ( (t-amyl)), 1- ,2- , 5623 zxft 5623- ,1- -1- ,1- -1- ,1- -1- , 6262 zxft 6262- , ,1- ,2- , 3256 zxft 3256- ,1- -1- , 3456 zxft 3456- , 3838 zxft 3838- , ,1- ,1- , 5749 zxft 5749- , 6595 zxft 6595- , 6898 zxft 6898- -4- , , (3428 zxft 3428- ), 3476 zxft 3476- , , ,1- , </xnotran> N-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, or n-eicosyl, and the like.
The "alkenyl group" refers to a group obtained by substituting a C — C single bond in the structure of the "alkyl group" with a C = C double bond, and includes a group in which two or more single bonds are substituted with a double bond (also referred to as a diene-group or a triene-group).
With respect to the "alkynyl group", reference may be made to the description of said "alkyl group" which is a group in which a single C — C bond is substituted with a triple C ≡ C bond in the structure of the "alkyl group", and also includes a group in which not only one but two or more single bonds are substituted with a triple bond (also referred to as diyne-yl or triyne-yl).
The "cycloalkyl group" is, for example, a cycloalkyl group having 3 to 24 carbon atoms, preferably a cycloalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, or a cycloalkyl group having 5 carbon atoms.
Specific "cycloalkyl" groups are for example: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or an alkyl (particularly methyl) substituent having 1 to 5 or 1 to 4 carbon atoms of these groups, bicyclo [1.1.0] butyl, bicyclo [1.1.1] pentyl, bicyclo [2.1.0] pentyl, bicyclo [2.1.1] hexyl, bicyclo [3.1.0] hexyl, bicyclo [2.2.1] heptyl, bicyclo [2.2.2] octyl, adamantyl, diamantanyl, decahydronaphthyl, or decahydroazulenyl group.
The "cycloalkylene group" is, for example, a cycloalkylene group having 3 to 24 carbon atoms, preferably a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkylene group having 3 to 16 carbon atoms, a cycloalkylene group having 3 to 14 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a cycloalkylene group having 5 to 10 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a cycloalkylene group having 5 to 6 carbon atoms, or a cycloalkylene group having 5 carbon atoms.
Specific examples of the "cycloalkylene group" include a divalent group obtained by removing one hydrogen from the "cycloalkyl group" (monovalent group).
"alkoxy" is a group represented by "Alk-O- (Alk is an alkyl)", and as for details of the alkyl group, a description of the "alkyl" may be cited.
The "aryloxy group" is a group represented by "Ar-O- (Ar is an aryl group)", and as for the details of the aryl group, the description of the "aryl group" can be cited.
The "substituted silyl group" is, for example, a silyl group substituted with at least one of an aryl group, an alkyl group, and a cycloalkyl group, and is preferably a triarylsilyl group, a trialkylsilyl group, a tricycloalkylsilyl group, a dialkylcycloalkylsilyl group, or an alkylbicycloalkylsilyl group.
"Triarylsilyl" is a silyl group substituted with three aryl groups, and with respect to the details of the aryl groups, reference is made to the description of the "aryl group".
Specific "triarylsilyl group" is, for example, triphenylsilyl group, diphenylmononaphthylsilyl group, monophenyldinaphthylsilyl group, or trinaphthylsilyl group, etc.
"Trialkylsilyl" is a silyl group substituted with three alkyl groups, and for details of the alkyl groups, reference may be made to the description of the "alkyl groups".
Specific "trialkylsilyl groups" are, for example: trimethylsilyl group, triethylsilyl group, tri-n-propylsilyl group, triisopropylsilyl group, tri-n-butylsilyl group, triisobutylsilyl group, tri-sec-butylsilyl group, tri-tert-butylsilyl group, ethyldimethylsilyl group, n-propyldimethylsilyl group, isopropyldimethylsilyl group, n-butyldimethylsilyl group, isobutyldimethylsilyl group, sec-butyldimethylsilyl group, tert-butyldimethylsilyl group, n-propyldiethylsilyl group, isopropyldiethylsilyl group, n-butyldiethylsilyl group, sec-butyldiethylsilyl group, methyldi-n-propylsilyl group, ethyldi-n-propylsilyl group, n-butyldi-n-propylsilyl group, sec-butyldi-n-propylsilyl group, tert-butyldi-n-propylsilyl group, methyldiisopropylsilyl group, ethyldiisopropylsilyl group, n-butyldiisopropylsilyl group, sec-butyldiisopropylsilyl group, or tert-butyldiisopropylsilyl group.
"Tricycloalkylsilyl" is a silyl group substituted with three cycloalkyl groups, and for the details of the cycloalkyl groups, reference may be made to the description of the "cycloalkyl groups".
Specific examples of the "tricycloalkylsilyl group" include tricyclopentylsilyl group, tricyclohexylsilyl group and the like.
"Dialkylcycloalkylsilyl" is a silyl group substituted with two alkyl groups and one cycloalkyl group, and for a detailed description of the alkyl and cycloalkyl groups, reference may be made to the descriptions of the "alkyl" and "cycloalkyl" groups.
"Alkylbicycloalkylsilyl" is a silyl group substituted with one alkyl group and two cycloalkyl groups, and for details of the alkyl and cycloalkyl groups, reference may be made to descriptions of the "alkyl" and "cycloalkyl" groups.
The substituents of the structural units represented by formula (1) can be selected according to the use of the polycyclic aromatic compound having a structure containing one or two or more of the structural units. Preferably: methyl, tert-butyl, adamantyl, phenyl, o-tolyl, naphthyl, biphenyl, terphenyl, diphenylamino, carbazolyl, dibenzofuranyl, dibenzothiophenyl, 3,5-dicarbazolylphenyl, carbazolyl-substituted phenyl, pyridyl, phenyl-substituted pyridyl, bipyridyl, piperidyl, phenyl-substituted piperidyl, pyrazinyl, phenyl-substituted pyrazinyl, triazinyl, 3,5-diphenyl-triazinyl, biphenyl-substituted triazinyl, carbazolyl-substituted triazinyl, cyano. When a polycyclic aromatic compound having a structure including one or two or more of the structural units represented by formula (1) is used as the hole-transporting layer or the hole-transporting host, the substituent is more preferably a diphenylamino group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a 3,5-dicarbazolylphenyl group, or a carbazolyl-substituted phenyl group. When used as an electron transporting layer or electron transporting host, the substituent is preferably a pyridyl group, a phenyl-substituted pyridyl group, a bipyridyl group, a piperidyl group, a phenyl-substituted piperidyl group, a pyrazinyl group, a phenyl-substituted pyrazinyl group, a triazinyl group, 3,5-diphenyl-triazinyl group, a biphenyl-substituted triazinyl group, a carbazolyl-substituted triazinyl group, or a cyano group. When used as a host material, the substituent is preferably phenyl, naphthyl, biphenyl, terphenyl, diphenylamino, carbazolyl, dibenzofuranyl, dibenzothiophenyl, 3,5-dicarbazolylphenyl, carbazolyl-substituted phenyl, pyridyl, phenyl-substituted pyridyl, bipyridyl, piperidyl, phenyl-substituted piperidyl, pyrazinyl, phenyl-substituted pyrazinyl, triazinyl, 3,5-diphenyl-triazinyl, biphenyl-substituted triazinyl, carbazolyl-substituted triazinyl.
R in L L1 、R L2 And R L3 Each independently is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl. In addition, R in Z Z1 、R Z2 And R Z3 Each independently is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl. At R L1 、R L2 、R L3 、R Z1 、R Z2 、R Z3 In (3), as the substituent referred to as "substituted or unsubstituted", there may be mentioned: aryl (which may be substituted with aryl or heteroaryl), heteroaryl (which may be substituted with aryl or heteroaryl), alkyl, cycloalkyl, or a substituent represented by any one of the following formulae.
[ solution 20]
Figure BDA0003858194960000231
< Structure containing one or more than two of the structural units >
The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure containing one or more than two structural units represented by the formula (1). The polycyclic aromatic compound having a structure containing one of the structural units is a polycyclic aromatic compound in which the structural unit represented by formula (1) is represented by the formula described above. The polycyclic aromatic compound having a structure containing two or more structural units represented by formula (1) is a compound corresponding to a multimer of the polycyclic aromatic compound in which the structural unit represented by formula (1) is represented by the above-described formula. The multimer is preferably a dimer to a hexamer, more preferably a dimer to a trimer, and particularly preferably a dimer. The multimer may be in a form of having a plurality of the unit structures in one compound, and may be in a form of being bonded so that any ring (a ring, B ring, or C ring) contained in the unit structure is shared among a plurality of unit structures, or in a form of being bonded so that any rings (a ring, B ring, or C ring) contained in the unit structure are condensed with each other. The unit structure may be in a form in which a plurality of units are bonded by a single bond, a linking group having 1 to 3 carbon atoms such as alkylene, phenylene, or naphthylene. Among these, the compound is preferably bonded so as to have a common ring.
< description of substitution by deuterium, cyano, or halogen >
At least one hydrogen in the polycyclic aromatic compound of the present invention may be substituted with deuterium, cyano, or halogen. Halogen is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, more preferably fluorine or chlorine.
< specific example of polycyclic aromatic Compound of the present invention >
Specific examples of the polycyclic aromatic compound of the present invention include compounds represented by any one of the following structural formulae.
[ solution 21]
Figure BDA0003858194960000241
[ solution 22]
Figure BDA0003858194960000251
[ solution 23]
Figure BDA0003858194960000252
[ formula 24]
Figure BDA0003858194960000261
[ solution 25]
Figure BDA0003858194960000271
[ solution 26]
Figure BDA0003858194960000281
[ solution 27]
Figure BDA0003858194960000291
[ solution 28]
Figure BDA0003858194960000301
The benzene ring in the structural formula can be respectively and independently substituted by aryl with 6 to 16 carbon atoms, heteroaryl with 2 to 20 carbon atoms, diarylamino (wherein, the aryl is aryl with 6 to 10 carbon atoms), diarylboron (wherein, the aryl is aryl with 6 to 10 carbon atoms, two aryl can be bonded through a single bond or a connecting group), alkyl with 1 to 12 carbon atoms or cycloalkyl with 3 to 16 carbon atoms, and the substituent can be substituted by at least one substituent selected from the group consisting of alkyl with 1 to 5 carbon atoms and cycloalkyl with 5 to 10 carbon atoms,
at least one hydrogen in the compounds represented by the structural formula may be substituted with deuterium, cyano, or halogen.
Further specific examples of the polycyclic aromatic compound include compounds represented by the following structural formulae.
[ solution 29]
Figure BDA0003858194960000311
[ solution 30]
Figure BDA0003858194960000321
[ solution 31]
Figure BDA0003858194960000331
[ chemical No. 32]
Figure BDA0003858194960000341
[ chemical formula 33]
Figure BDA0003858194960000351
[ chemical 34]
Figure BDA0003858194960000361
[ solution 35]
Figure BDA0003858194960000371
[ solution 36]
Figure BDA0003858194960000381
[ solution 37]
Figure BDA0003858194960000391
[ solution 38]
Figure BDA0003858194960000401
[ solution 39]
Figure BDA0003858194960000411
[ solution 40]
Figure BDA0003858194960000421
2. Method for producing polycyclic aromatic compound
Basically, the polycyclic aromatic compound of the present invention can be produced by first bonding the a ring, the B ring and the C ring with a bonding group (a group containing X, Y, Z or L) to produce an intermediate (first reaction), and then producing a final product (second reaction) by a cyclization reaction.
In the first Reaction, for example, in the case of etherification, a nucleophilic substitution Reaction, a general Reaction such as Ullmann Reaction (Ullmann Reaction), or the like may be used, and in the case of amination, a general Reaction such as a Buchwald-Hartwig Reaction (Buchwald-Hartwig Reaction) may be used. In the second Reaction, a Cadong (Cadogan) cyclization Reaction, a Tandem Hetero-Friedel-Crafts Reaction (Tandem Hetero-Friedel-Crafts Reaction), or the like can be used.
The second reaction includes four cases of cyclization reactions as shown in the following schemes (1) to (4). In the following schemes (1) to (4), substituents used for the cyclization reaction, such as a leaving group bonded to the a ring, the B ring, the C ring, L, X, Y, and Z, are omitted.
[ solution 41]
Figure BDA0003858194960000431
[ solution 42]
Figure BDA0003858194960000432
Hereinafter, the production method of the cyclization reaction will be described with reference to the above-mentioned examples, including the compound (a), the compound (B), the compound (C), the compound (d), the compound (e), the compound (f), the compound (g), the compound (h), the compound (i) and the compound (j) in which ring a, ring B and ring C are benzene rings.
Examples of case 1 include the methods described in the flow (5), the flow (6), and the flow (7).
[ solution 43]
Figure BDA0003858194960000441
In scheme (5), PPh is used 3 Or P (OEt) 3 An intermediate having a 7-membered ring can be synthesized by reductively cyclizing an intermediate having a nitrophenyl group and subjecting the intermediate to a cardo-poly (Cadogan) cyclization reaction. Then, the intermediate having a 7-membered ring obtained is subjected to a cross-coupling reaction with a halogenated aryl compound using a copper catalyst, a palladium catalyst, or the like, whereby the target compound can be obtained.
[ solution 44]
Figure BDA0003858194960000442
In the scheme (6), the target compound can be obtained by performing an intramolecular cross-coupling reaction using a copper catalyst, a palladium catalyst, or the like.
In the above-mentioned schemes (5) and (6), copper powder, copper oxide, copper halide or the like is used when a copper catalyst is used. The base used is cesium carbonate, potassium carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, sodium hydrogen carbonate, tripotassium phosphate, sodium hydride, etc., and the reaction accelerator includes: crown ethers (e.g., 18-crown-6-ether), polyethylene glycol (PEG), polyethylene glycol dialkyl ethers (PEGDM), and the like. The reaction solvent may be N, N-dimethylformamide, nitrobenzene, dimethyl sulfoxide, dichlorobenzene, o-dichlorobenzene, quinoline, or the like. The reaction temperature is 160 to 250 ℃, but when the reactivity of the substrate is low, the reaction can be carried out at a higher temperature using an autoclave or the like.
In the case of using a palladium catalyst, palladium acetate, palladium chloride, palladium bromide, tris (dibenzylideneacetone) dipalladium (0), tris (dibenzylideneacetone) dipalladium chloroform complex (0), tetrakis (triphenylphosphine) palladium (0), [1,1' -bis (diphenylphosphino) ferrocene ] palladium (II) dichloride dichloromethane complex (1:1), and the like can be used. The bases used may be exemplified by: lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, sodium hydrogen carbonate, sodium hydride, potassium alkoxide (e.g., potassium methoxide, potassium ethoxide, potassium n-propoxide, potassium isopropoxide, potassium n-butoxide, potassium t-butoxide, etc.), and sodium alkoxide (e.g., sodium methoxide, sodium ethoxide, sodium n-propoxide, sodium isopropoxide, sodium n-butoxide, sodium t-butoxide, etc.). As the reaction accelerator, 2,2'- (diphenylphosphino) -1,1' -binaphthyl, 1,1'- (diphenylphosphino) ferrocene, dicyclohexylphosphinobenzene, di-t-butylphosphinobiphenyl, tri (t-butyl) phosphine, 1- (N, N-dimethylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (N, N-dibutylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (methoxymethyl) -2- (di-t-butylphosphino) ferrocene, 1,1' -bis (di-t-butylphosphino) ferrocene, 2,2 '-bis (di-t-butylphosphino) -1,1' -binaphthyl, 2-methoxy-2 '- (di-t-butylphosphino) -1,1' -binaphthyl, and the like can be used. The reaction solvent may be an aromatic hydrocarbon solvent such as benzene, toluene, xylene, mesitylene, or the like. The solvent can be used alone or in the form of a mixed solvent. The reaction temperature is usually in the range of 50 ℃ to 200 ℃, and more preferably 80 ℃ to 140 ℃.
[ solution 45]
Figure BDA0003858194960000451
In the scheme (7), the target compound can be obtained by conducting an intramolecular coupling reaction using a base in the absence of a catalyst or a copper catalyst. In the case of using a copper catalyst, copper powder, copper oxide, copper halide, or the like is used. The base is cesium carbonate, potassium carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate, tripotassium phosphate, sodium hydride, etc. Further, as the reaction solvent, N-dimethylformamide, nitrobenzene, dimethyl sulfoxide, N-methyl-2-pyrrolidone, dichlorobenzene, o-dichlorobenzene, quinoline, or the like can be used. The reaction temperature is 160 to 250 ℃, but when the reactivity of the substrate is low, the reaction can be carried out at a higher temperature using an autoclave or the like.
Examples of case 2 include the methods described in the flow (8), the flow (9), the flow (10), and the flow (11).
[ solution 46]
Figure BDA0003858194960000461
[ solution 47]
Figure BDA0003858194960000462
In the above-mentioned schemes (8) and (9), when a catalyst is used, a sulfonic acid derivative, a diazabicyclo derivative, a solid acid having a sulfonic acid group, or the like can be used.
Examples of sulfonic acid derivatives include: sulfonic acid, methanesulfonic acid, ethanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, and the like.
Examples of diazabicyclic derivatives include: diazabicycloundecene (DBU), diazabicyclononene (DBN), 1,4-Diazabicyclo [2.2.2] octane (1,4-Diazabicyclo [2.2.2] octane, DABCO), and the like.
Specific examples of the solid acid having a sulfonic acid group include: polystyrene sulfonate ion exchange resins manufactured by llc of Sigma Aldrich Japan (Sigma Aldrich Japan), such as admicrobo listeria (AMBERLYST) 15 (H), admicrobo listeria (AMBERLYST) 16 (H), admicrobo listeria (AMBERLYST) 36 (H), admicrobo plumet (AMBERLITE) IR120 (H), admicrobent (AMBERJET) 1200 (H), dowtex (DOWEX) 15 wx 2, dowtex (DOWEX) 15 wx 4, dowtex (DOWEX) 15 wx 8, and the like; examples of the sulfonic acid-immobilized acid catalysts include tacrine (Taycacure) -6, tacrine (Taycacure) -10, and tacrine (Taycacure) -15, which are silica gel series catalysts manufactured by TAYCA, inc.
As the reaction solvent, toluene, xylene, o-xylene, p-xylene, m-xylene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, etc. can be used. The solvent can be used alone or in the form of a mixed solvent. The reaction temperature is usually in the range of 100 ℃ to 200 ℃. Since the present reaction is a dehydration reaction, it is desirable to use an apparatus equipped with a Dean-Stark trap (Dean-Stark trap).
[ solution 48]
Figure BDA0003858194960000471
[ solution 49]
Figure BDA0003858194960000472
In the above-mentioned schemes (10) and (11), examples of the base include: n, N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N-dimethylaniline, N-dimethyltoluidine, 2,6-lutidine, and the like.
As the reaction solvent, o-dichlorobenzene, chlorobenzene, xylene, o-xylene, p-xylene, m-xylene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, etc. can be used. The solvent can be used alone or in the form of a mixture. The reaction temperature is usually in the range of 120 ℃ to 220 ℃.
[ solution 50]
Figure BDA0003858194960000473
[ solution 51]
Figure BDA0003858194960000481
In the above-mentioned schemes (12) and (13), examples of the base include: pyridine, N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N-dimethylaniline, N-dimethyltoluidine, 2,6-lutidine, and the like.
As the reaction solvent, toluene, xylene, o-xylene, p-xylene, m-xylene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, etc. can be used. The solvent can be used alone or in the form of a mixed solvent. The reaction temperature is usually in the range of 0 ℃ to 180 ℃.
Examples of case 3 include the methods described in the flow (14) and the flow (15).
[ solution 52]
Figure BDA0003858194960000482
[ Hua 53]
Figure BDA0003858194960000491
In the above-mentioned flow (14) and flow (15), copper powder, copper oxide, copper halide or the like is used in the case of using a copper catalyst. The base used is cesium carbonate, potassium carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, sodium hydrogen carbonate, tripotassium phosphate, sodium hydride, etc., and the reaction accelerator includes: crown ethers (e.g., 18-crown-6-ether), polyethylene glycol (PEG), polyethylene glycol dialkyl ethers (PEGDM), and the like. Further, as the reaction solvent, N-dimethylformamide, nitrobenzene, dimethyl sulfoxide, N-methyl-2-pyrrolidone, dichlorobenzene, o-dichlorobenzene, quinoline, or the like can be used. The reaction temperature is 160 to 250 ℃, but when the reactivity of the substrate is low, the reaction can be carried out at a higher temperature using an autoclave or the like.
In the case of using a palladium catalyst, palladium acetate, palladium chloride, palladium bromide, tris (dibenzylideneacetone) dipalladium (0), tris (dibenzylideneacetone) dipalladium chloroform complex (0), tetrakis (triphenylphosphine) palladium (0), [1,1' -bis (diphenylphosphino) ferrocene ] palladium (II) dichloride dichloromethane complex (1:1), and the like can be used. The bases used may be mentioned: lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, sodium hydrogen carbonate, sodium hydride, potassium alkoxide (for example, potassium methoxide, potassium ethoxide, potassium n-propoxide, potassium isopropoxide, potassium n-butoxide, potassium t-butoxide, etc.), and sodium alkoxide (for example, sodium methoxide, sodium ethoxide, sodium n-propoxide, sodium isopropoxide, sodium n-butoxide, sodium t-butoxide, etc.). As the reaction accelerator, 2,2'- (diphenylphosphino) -1,1' -binaphthyl, 1,1'- (diphenylphosphino) ferrocene, dicyclohexylphosphinobenzene, di-t-butylphosphinobiphenyl, tri (t-butyl) phosphine, 1- (N, N-dimethylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (N, N-dibutylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (methoxymethyl) -2- (di-t-butylphosphino) ferrocene, 1,1' -bis (di-t-butylphosphino) ferrocene, 2,2 '-bis (di-t-butylphosphino) -1,1' -binaphthyl, 2-methoxy-2 '- (di-t-butylphosphino) -1,1' -binaphthyl, and the like can be used. The reaction solvent may be an aromatic hydrocarbon solvent such as benzene, toluene, xylene, mesitylene, or the like. The solvent can be used alone or in the form of a mixture. The reaction temperature is usually in the range of 50 ℃ to 200 ℃, and more preferably 80 ℃ to 140 ℃.
Examples of case 4 include the methods described in the flow (16) and the flow (17).
[ formula 54]
Figure BDA0003858194960000492
In the process (16), deprotonation is performed using a deprotonating agent such as n-butyllithium, sec-butyllithium, or tert-butyllithium, boron trichloride or boron tribromide is added to perform lithium-boron metal exchange, and AlCl is added 3 The target compound can be obtained by subjecting a Friedel-Crafts type reaction to Lewis acid (Lewis acid) and Bronsted base (Bronsted base) such as 2,2,6,6-tetramethylpiperidine (2,2,6,6-tetramethylpiperidine, TMP).
[ solution 55]
Figure BDA0003858194960000501
In the process (17), after deprotonation is carried out using a deprotonating agent such as n-butyllithium, sec-butyllithium or tert-butyllithium, a phosphorus introducing agent and sulfur are sequentially added, and finally AlCl is added 3 And Lewis acids and Bronsted bases such as N, N-diisopropylethylamine, and the like, thereby performing Friedel-Crafts type reactions to obtain a compound as phosphorus sulfide. The obtained phosphorus sulfide compound is treated with m-Chloroperbenzoic acid (m-CPBA), whereby a phosphine oxide compound can be obtained. Further, triethylphosphine (PEt) is used 3 ) The phosphine oxide compound is treated, whereby a compound as a cyclic phosphine can be obtained.
In the schemes (16) and (17), as the deprotonating agent, alkyllithium such as MeLi, s-BuLi, t-BuLi and PhLi, grignard reagent such as MeMgBr, etMgBr and n-BuMgBr, alkali metal hydride such as NaH and KH, and the like can be used in addition to n-BuLi.
As lewis acids, mention may be made of: alCl 3 、AlBr 3 、BF 3 -OEt 2 、BCl 3 、BBr 3 、GaCl 3 、GaBr 3 、InCl 3 、InBr 3 、In(OTf) 3 、SnCl 4 、SnBr 4 、AgOTf、Sc(OTf) 3 、ZnCl 2 、ZnBr 2 、Zn(OTf) 2 、MgCl 2 、MgBr 2 、Mg(OTf) 2 And the like.
As the bransted base, there can be used: n, N-diisopropylethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, 2,4,6-collidine, 2,6-lutidine, triethylamine, triisobutylamine, and the like.
As the solvent, there can be used: anhydrous ether solvents such as anhydrous diethyl ether, anhydrous Tetrahydrofuran (THF), and anhydrous dibutyl ether, aromatic hydrocarbon solvents such as benzene, toluene, xylene, and mesitylene, and aromatic halide solvents such as chlorobenzene and 1,2-dichlorobenzene.
In the scheme (17), examples of the phosphorus introducing agent include: PF (particle Filter) 3 、PCl 3 、PBr 3 、PI 3 Etc. halides, P (OMe) 3 、P(OEt) 3 、P(O-nPr) 3 、P(O-iPr) 3 、P(O-nBu) 3 、P(O-iBu) 3 、P(O-secBu) 3 、P(O-t-Bu) 3 Isoalkoxy derivatives, P (OPh) 3 P (O-naphthyl) 3 Isoaryloxy derivative, P (OAc) 3 P (O-trifluoroacetyl group) 3 P (O-propionyl) 3 P (O-butyryl) 3 P (O-benzoyl) 3 Iso-acyloxy derivatives, PCl (NMe) 2 ) 2 、PCl(NEt 2 ) 2 、PCl(NPr 2 ) 2 、PCl(NBu 2 ) 2 、PBr(NMe 2 ) 2 、PBr(NEt 2 ) 2 、PBr(NPr 2 ) 2 、PBr(NBu 2 ) 2 And the like halogenated amino derivatives.
The above-mentioned schemes (5) to (17) are methods for producing the representative compounds of the polycyclic aromatic compound of the present invention, and other compounds can be synthesized by a method similar thereto. The polycyclic aromatic compound of the present invention also includes a compound in which at least a part of hydrogen is substituted with deuterium, cyano or halogen, and such a compound can be produced in the same manner as described above by using a raw material in which a desired position is halogenated with deuteration, cyanation, fluorination, chlorination or the like.
3. Organic device
The polycyclic aromatic compound of the present invention is useful as a material for organic devices. Examples of the organic device include: organic electroluminescent devices, organic field effect transistors, organic thin film solar cells, and the like.
3-1. Organic electroluminescent element
Hereinafter, the organic EL device of the present embodiment will be described in detail with reference to the drawings. Fig. 1 is a schematic sectional view showing an organic EL element according to the present embodiment.
< Structure of organic electroluminescent element >
The organic EL element 100 shown in fig. 1 includes: the light-emitting device comprises a substrate 101, an anode 102 disposed on the substrate 101, a hole injection layer 103 disposed on the anode 102, a hole transport layer 104 disposed on the hole injection layer 103, a light-emitting layer 105 disposed on the hole transport layer 104, an electron transport layer 106 disposed on the light-emitting layer 105, an electron injection layer 107 disposed on the electron transport layer 106, and a cathode 108 disposed on the electron injection layer 107.
In addition, the organic EL element 100 may be formed by reversing the manufacturing order, for example, by a structure including: the organic light emitting diode comprises a substrate 101, a cathode 108 arranged on the substrate 101, an electron injection layer 107 arranged on the cathode 108, an electron transport layer 106 arranged on the electron injection layer 107, a light emitting layer 105 arranged on the electron transport layer 106, a hole transport layer 104 arranged on the light emitting layer 105, a hole injection layer 103 arranged on the hole transport layer 104, and an anode 102 arranged on the hole injection layer 103.
All of the layers are not indispensable, and the minimum constituent unit is configured to include the anode 102, the light-emitting layer 105, and the cathode 108, and the hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection layer 107 are layers that can be arbitrarily provided. In addition, each of the layers may include a single layer, or may include a plurality of layers.
As the form of the layers constituting the organic EL element, in addition to the structural form of the above-mentioned "substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode", the material may be in the structural form of "substrate/anode/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/light-emitting layer/hole injection layer/light-emitting layer/electron injection layer/cathode", "substrate/anode/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole transport layer/light-emitting layer/electron injection layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron transport layer/cathode", "substrate/anode/light-emitting layer/electron injection layer/cathode".
The organic EL element may further have either or both of an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer) selected from the group. The electron blocking layer has a LUMO shallower than the light-emitting layer and a HOMO closer to the light-emitting layer or the hole transport layer, and is disposed between the light-emitting layer and the hole transport layer. Since electrons are retained in the light-emitting layer and do not leak to the hole transport layer, the reduction in lifetime due to deterioration of the hole transport layer and the reduction in efficiency due to reduction in recombination efficiency can be prevented. The hole blocking layer has a HOMO deeper than the light emitting layer and a LUMO close to the light emitting layer or the hole transporting layer, and is disposed between the light emitting layer and the electron transporting layer. Since the holes are retained in the light-emitting layer and do not leak to the electron transport layer, the lifetime reduction due to the deterioration of the electron transport layer and the efficiency reduction due to the reduction of recombination efficiency can be prevented. The hole injection/transport layer may also double as an electron blocking layer. The electron injection/transport layer may also double as a hole blocking layer.
The organic EL element may further have a high T1 layer. The high T1 layer has a higher T1 than a host compound, an assist dopant compound, or an emitting dopant compound used in the light-emitting layer, and is disposed between the light-emitting layer and the hole-transport layer and/or between the light-emitting layer and the electron-blocking layer. The value of the T1 energy differs depending on the light emitting mechanism of the element, but has a higher T1 than the compound used in the host. By providing the high T1 layer around the light-emitting layer, triplet energy can be confined, and triplet energy that is not involved in light emission in a fluorescent molecule in general is converted into singlet energy, thereby achieving high efficiency. The hole injection/transport layer or the electron blocking layer may also double as the high T1 layer. The electron injection/transport layer or the hole blocking layer may also double as the high T1 layer.
The polycyclic aromatic compound of the present invention is preferably used as a material for an organic electroluminescent element. In general, a compound having a donor structure may be used in a hole transporting host material and a hole transporting layer in a light emitting layer, a compound having an acceptor structure may be used in an electron transporting host material and an electron transporting layer, and a compound having a donor structure and an acceptor structure may be used in any one of a hole transporting layer, a host in a light emitting layer, and an electron transporting layer. For example, refer to Advanced Functional Materials (Advanced Functional Materials) 2020, 2008332, etc. More specifically, the donor structure includes a triarylamine structure and a carbazole structure, and the acceptor structure includes a triazine structure, a pyrimidine structure, and a pyridine structure. The polycyclic aromatic compound of the present invention can be used as a host material, a hole transport layer material, an electron transport layer material, or the like in the light-emitting layer depending on the partial structure.
< substrate in organic electroluminescent element >
The substrate 101 is a support of the organic EL element 100, and quartz, glass, metal, plastic, or the like is generally used. The substrate 101 is formed in a plate shape, a film shape, or a sheet shape according to the purpose, and for example, a glass plate, a metal foil, a plastic film, a plastic sheet, or the like can be used. Among them, a glass plate and a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, polysulfone are preferable. In the case of a glass substrate, soda-lime glass, alkali-free glass, or the like can be used, and the thickness may be sufficient to maintain mechanical strength. In addition, in order to improve the gas barrier property, a gas barrier film such as a fine silicon oxide film may be provided on at least one surface of the substrate 101, and when a synthetic resin plate, film or sheet having low gas barrier property is used as the substrate 101, it is particularly preferable to provide a gas barrier film.
< Anode in organic electroluminescent element >
The anode 102 functions to inject holes into the light-emitting layer 105. When at least one of the hole injection layer 103 and the hole transport layer 104 is provided between the anode 102 and the light-emitting layer 105, holes are injected into the light-emitting layer 105 through these layers.
Examples of the material for forming the anode 102 include inorganic compounds and organic compounds. Examples of the inorganic compound include: metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (Indium Oxide, tin Oxide, indium Tin Oxide (ITO), indium Zinc Oxide (IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, or Nesa glass), and the like. Examples of the organic compound include: polythiophene such as poly (3-methylthiophene), and conductive polymers such as polypyrrole and polyaniline. Further, the organic EL element can be used by appropriately selecting from materials used as an anode of the organic EL element.
< hole injection layer, hole transport layer in organic electroluminescent element >
The hole injection layer 103 functions to efficiently inject holes transferred from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 functions to efficiently transport holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light-emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are formed by laminating or mixing one or more kinds of hole injection/transport materials. Further, an inorganic salt such as iron (III) chloride may be added to the hole injection/transport material to form a layer.
The hole injecting/transporting substance needs to efficiently inject/transport holes from the positive electrode between electrodes to which an electric field is applied, and it is desirable that the hole injecting efficiency is high and the injected holes are efficiently transported. Therefore, a substance having a small ionization potential, a large hole mobility, and excellent stability, and in which impurities serving as traps are not easily generated during production and use, is preferable. The polycyclic aromatic compound of the present invention is also preferably used as a material for the hole transport layer.
As the material for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds conventionally used as charge transport materials for holes in photoconductive materials, p-type semiconductors, and known compounds used in hole injection layers and hole transport layers of organic EL devices. Specific examples of these are: carbazole derivatives (e.g., N-phenylcarbazole and polyvinylcarbazole), biscarbazole derivatives such as bis (N-arylcarbazole) and bis (N-alkylcarbazole), triarylamine derivatives (e.g., polymers having an aromatic tertiary amino group in the main chain or side chain, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N '-diphenyl-N, N' -bis (3-methylphenyl) -4,4 '-diaminobiphenyl, N' -diphenyl-N, N '-dinaphthyl-4,4' -diaminobiphenyl, N '-diphenyl-N, N' -bis (3-methylphenyl) -4,4 '-diphenyl-1,1' -diamine, N '-dinaphthyl-N, N' -diphenyl-4,4 '-diphenyl-1,1' -diamine, N '-di (3-methylphenyl) -3236' -diaminobiphenyl 4 ,N 4 ' -Diphenyl-N 4 ,N 4 '-bis (9-phenyl-9H-carbazol-3-yl) - [1,1' -biphenyl]-4,4' -diamine, N 4 ,N 4 ,N 4 ',N 4 '-tetrakis [1,1' -biphenyl]-4-yl- [1,1' -biphenyl]Triphenylamine derivatives such as-4,4 '-diamine, 4,4',4 ″ -tris (3-methylphenyl (phenyl) amino) triphenylamine, starburst amine derivatives, and the like), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, and the like), pyrazoline derivatives, hydrazone-based compounds, benzofuran derivatives or thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, and the like), heterocyclic compounds such as porphyrin derivatives, polysilanes, and the like. In the polymer system, a polycarbonate or a styrene derivative, polyvinylcarbazole, polysilane, or the like having the monomer in the side chain is preferable, but there is no particular limitation as long as it is a compound which forms a thin film necessary for manufacturing a light-emitting element, can inject holes from an anode, and can transport holes.
Further, it is also known that the conductivity of an organic semiconductor is strongly affected by doping. Such an organic semiconductor matrix material contains a compound having a good electron donating property or a compound having a good electron accepting property. For the doping of electron-donating substances, strong electron acceptors such as Tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinodimethane (2,3,5,6-tetrafluorotetracycacyno-1,4-benzoquinodimethane, F4 TCNQ) are known (see, for example, references "m. Fayfer, a. Bayer, t. Frietz, k. Rio (m.pfeiffer, a.beyer, t.fritz, k.leo)," applied physics letters (pfl.phys.lett.), "73 (22), 3202-3204 (1998)" and references "j. Buyhawitz, m. French, t. Ietz, k. K.731, k.J.appl.," applied letters (pfl. Appl.1998) ", and references" j. Buhernwitz, m. French, t. Peyth.73, t.1998) ", and" applied letters. These generate so-called holes by an electron transfer process of an electron donor type base substance (hole transport substance). The conductivity of the base material varies considerably depending on the number and mobility of holes. As a matrix material having a hole transporting property, for example, a benzidine derivative (N, N '-diphenyl-N, N' -bis (3-methylphenyl) -1,1'-biphenyl-4,4' -diamine (N, N '-diphenyl-N, N' -bis (3-methylphenyl) -1,1'-biphenyl-4,4' -diamine, TPD)) or a starburst amine derivative (4,4 ',4 ″ -tris (N, N-diphenylamino) triphenylamine (4,4', 4 ″ -tris (N, N-diphenylamino) triphenylamine, TDATA), etc.), or a specific metal phthalocyanine (particularly zinc phthalocyanine (ZnPc), etc.) is known (japanese patent laid-open No. 2005-167175).
The hole injection layer material and the hole transport layer material may be used as a hole layer material as a polymer compound obtained by polymerizing a reactive compound, which is obtained by substituting a reactive substituent in the hole injection layer material and the hole transport layer material, as a monomer, or as a polymer cross-linked product thereof obtained by reacting a main chain polymer with the reactive compound, or as a pendant-type polymer compound obtained by substituting a reactive substituent in the hole injection layer material and the hole transport layer material, or as a pendant-type polymer cross-linked product thereof.
< light-emitting layer in organic electroluminescent element >
The light-emitting layer 105 emits light by recombination of holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for forming the light-emitting layer 105 may be a compound (light-emitting compound) which emits light by being excited by recombination of holes and electrons, and is preferably a compound which can be formed into a stable thin film shape and which exhibits strong light emission (fluorescence) efficiency in a solid state. The polycyclic aromatic compound of the present invention is also preferably used as a material for a light-emitting layer.
The light-emitting layer may be a single layer or may include a plurality of layers, and each of the layers is formed of a material (host material or dopant material) for the light-emitting layer. The host material and the dopant material may be one kind or a combination of two or more kinds, respectively. The dopant material may be contained within the bulk of the host material, or may be contained within a portion of the host material, either. The doping method may be a co-evaporation method with the host material, a simultaneous evaporation method in which the host material is mixed in advance, or a wet film formation method in which the host material is mixed in advance with an organic solvent and then the film is formed.
The amount of the host material to be used differs depending on the type of the host material, and may be determined in accordance with the characteristics of the host material. The amount of the host material used is preferably 50 to 99.999 mass%, more preferably 80 to 99.95 mass%, and still more preferably 90 to 99.9 mass% based on the entire mass of the light-emitting layer material.
The amount of the dopant material used differs depending on the type of the dopant material, and may be determined by matching the characteristics of the dopant material. The amount of the dopant material used is preferably 0.001 to 50 mass%, more preferably 0.05 to 20 mass%, and still more preferably 0.1 to 10 mass% based on the entire mass of the light-emitting layer material. The above range is preferable, for example, in terms of preventing the concentration quenching phenomenon. In addition, from the viewpoint of durability, it is also preferable that a part or all of hydrogen atoms of the dopant material be deuterated.
As dopant materials, emissive dopants and auxiliary dopant materials may be used. As the auxiliary dopant material, a thermally active delayed fluorescence material is preferably used. In the organic electroluminescent element using the auxiliary dopant material, it is preferable that the emission dopant material is used in a low concentration in terms of preventing the concentration quenching phenomenon. In terms of the efficiency of the thermally active delayed fluorescence mechanism, it is preferable that the amount of the auxiliary dopant material used be high. Further, in the organic electroluminescent element using the thermally active delayed fluorescence auxiliary dopant material, it is preferable that the amount of the emitting dopant material used is lower than the amount of the auxiliary dopant material used in terms of the efficiency of the thermally active delayed fluorescence mechanism of the auxiliary dopant material.
When the assist dopant material is used, the amounts of the host material, the assist dopant material, and the emission dopant material used are 40 to 99 mass%, 59 to 1 mass%, and 20 to 0.001 mass%, preferably 60 to 95 mass%, 39 to 5 mass%, and 10 to 0.01 mass%, more preferably 70 to 90 mass%, 29 to 10 mass%, and 5 to 0.05 mass%, respectively, based on the total mass of the light-emitting layer material.
< host Material >
As the host material, there can be mentioned: condensed ring derivatives such as anthracene and pyrene, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzofluorene derivatives, N-phenylcarbazole derivatives, carbazonitrile derivatives, and the like, which have been known as light-emitting bodies from the past.
From the viewpoint of promoting but not inhibiting the generation of TADF in the light-emitting layer, the triplet energy of the host material is preferably higher than the triplet energy of the dopant or the assist dopant having the highest triplet energy in the light-emitting layer, and specifically, the triplet energy of the host material is preferably 0.01eV or more, more preferably 0.03eV or more, and further preferably 0.1eV or more. In addition, a compound having TADF activity may also be used in the host material.
The main material may be one kind or a combination of plural kinds. In the case of a combination of a plurality of types, a combination of a hole-transporting host material and an electron-transporting host material is preferable.
The polycyclic aromatic compound of the present invention can be preferably used as a host material. The polycyclic aromatic compound of the present invention can be used alone, or can be used as a hole-transporting host material or an electron-transporting host material.
[ hole-transporting host Material (HH) ]
Examples of the preferred hole-transporting host material (HH) include compounds represented by the formula (HH-1) and compounds having a partial structure represented by the formula (HH-1), in addition to the polycyclic aromatic compound of the present invention.
[ solution 56]
Figure BDA0003858194960000551
In the formula (HH-1),
q is > O, > S, or > N-A,
one carbon atom adjacent to the carbon atom bonded to Q in each of the two phenyl groups in the formula (HH-1) may be bonded to each other through L,
l is a single bond, > O, > S or > C (-A) 2 ，
A is a hydrogen atom, aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, > C (-A) 2 Two of A may bond to each other to form an aryl, heteroaryl, cycloalkyl.
When the hole-transporting host material includes the structure represented by formula (HH-1) as a partial structure, one partial structure may be included, but two or more partial structures are also preferably included. When two or more are included, the two or more partial structures may be the same as or different from each other. Two or more partial structures may be bonded to each other by a single bond, may be bonded so as to share any ring included in the partial structures, and may be bonded so as to condense any ring included in the partial structures. The partial structure may further have a substituent selected from aryl, heteroaryl, diarylamino, or aryloxy.
The hole-transporting host material is preferably a compound including one or more partial structures selected from the group consisting of a triarylamine structure, a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring, and a condensed polycyclic ring containing phenoxazine or phenothiazine. The hole-transporting host material may comprise one such partial structure, but preferably comprises two or more. When two or more are included, the two or more partial structures may be the same as or different from each other.
Specific examples of the hole-transporting host material include the following compounds.
[ solution 57]
Figure BDA0003858194960000561
[ solution 58]
Figure BDA0003858194960000571
[ chemical 59]
Figure BDA0003858194960000581
[ solution 60]
Figure BDA0003858194960000591
[ solution 61]
Figure BDA0003858194960000601
[ solution 62]
Figure BDA0003858194960000611
[ solution 63]
Figure BDA0003858194960000621
[ chemical formula 64]
Figure BDA0003858194960000631
[ solution 65]
Figure BDA0003858194960000641
Of these, preferred are HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92, and HH-1-106 to HH-1-108.
[ Electron-transporting host Material (EH) ]
Examples of the electron-transporting host material (EH) include a compound represented by the formula (EH-1) and a compound having a partial structure represented by the formula (EH-1), in addition to the polycyclic aromatic compound of the present invention.
[ solution 66]
Figure BDA0003858194960000642
In the formula (EH-1),
j is each independently = C (-a) -, or = N-, at least three J are = C (-a) -,
z is-O-, -S-, -C (= O) -, -P (= O) (-A) -, -P (= S) (-A) -, -N (-A) -, -B (-A) -, or-S (= O) 2 -，
J adjacent to the carbon atom to which Z is bonded and A to which Z is bonded may be bonded to each other via L,
l is a single bond, > O, > S or > C (-A) 2 ，
A is hydrogen, aryl, heteroaryl, diarylaminoAlkyl, cycloalkyl, triarylsilyl, alkoxy or aryloxy, > C (-A) 2 Two of A may bond to each other to form an aryl, heteroaryl, cycloalkyl,
when all J are = C (-a) -, either a or Z has a heteroatom.
As for the aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, triarylsilyl, alkoxy, or aryloxy group represented by A in the formula (EH-1), the description of A in the formula (HH-1) can be referred to. As for the aryl, heteroaryl and cycloalkyl groups in the case where two A's in the formula (EH-1) are bonded to each other to form an aryl, heteroaryl and cycloalkyl group, the description of the formula (HH-1) can be referred to.
When the electron-transporting host material includes the structure represented by the formula (EH-1) as a partial structure, one partial structure may be included, but two or more partial structures are also preferably included. When two or more are included, the two or more partial structures may be the same as or different from each other. Two or more partial structures may be bonded to each other by a single bond, may be bonded so as to share any ring included in the partial structures, or may be bonded so as to condense any ring included in the partial structures. The partial structure may further have a substituent selected from aryl, heteroaryl, diarylamino, or aryloxy.
Specific examples of the electron-transporting host material include the following compounds.
[ solution 67]
Figure BDA0003858194960000651
[ solution 68]
Figure BDA0003858194960000661
[ solution 69]
Figure BDA0003858194960000671
[ solution 70]
Figure BDA0003858194960000681
[ solution 71]
Figure BDA0003858194960000691
[ chemical formula 72]
Figure BDA0003858194960000701
[ solution 73]
Figure BDA0003858194960000711
[ chemical 74]
Figure BDA0003858194960000712
Other preferable examples of the electron-transporting host material (the compound having a partial structure represented by formula (EH-1)) include a polycyclic aromatic compound represented by formula (EH-1 b) below and a polymer of a polycyclic aromatic compound having a plurality of structures represented by formula (EH-1 b) below.
[ solution 75]
Figure BDA0003858194960000721
In the formula (EH-1 b),
R 1 、R 2 、R 3 、R 4 and R 5 (hereinafter also referred to as "R") 1 Etc.) are each independently hydrogen or a substituent selected from substituent group Z.
In the formula (EH-1 b), X 1 And X 2 Independently of one another > N-R (aminic nitrogen), > O, > C (-R) 2 And > S or > Se, X 1 And X 2 Not simultaneously is > C (-R) 2 ，
The more than N-R and the more than C (-R) 2 Wherein R is independently hydrogen or a substituent selected from substituent group Z, which may be further substituted with aryl, heteroaryl, alkyl or cycloalkyl (above is the second substituent), said > N-R and > C (-R) 2 R in (b) may be independently bonded to at least one of the a-ring, the b-ring and the c-ring via a connecting group or a single bond, respectively.
Y 1 、Y 2 、Y 3 、Y 4 、Y 5 And Y 6 (hereinafter also referred to as "Y 1 Etc.) are each independently = C (-R) -or = N- (pyridinylazide), at least one is = N- (pyridinylazide),
r in = C (-R) -is each independently hydrogen or a substituent selected from substituent group Z.
The R is 1 、R 2 、R 3 、R 4 And R 5 And as said Y 1 ～Y 6 R of (a) = C (-R) -, the adjacent groups in R may be bonded to each other and form an aryl ring or a heteroaryl ring together with at least one of the a ring, the b ring and the C ring, and the formed ring may be substituted with at least one group selected from the substituent group Z.
At least one hydrogen in the compound and the structure represented by the formula (EH-1 b) may be substituted with a cyano group, a halogen or deuterium.
In the formula (EH-1 b), R is preferred 1 、R 2 、R 3 、R 4 And R 5 Are both hydrogen, or R 3 And R 4 Are all hydrogen and are selected from the group consisting of R 1 、R 2 And R 5 Any one or more of the groups is a substituent other than hydrogen, and the others are hydrogen. As the substituent, an alkyl group, an aryl group which may be substituted with an alkyl group or a heteroaryl group, a heteroaryl group which may be substituted with an alkyl group or an aryl group, or a diarylamino group which may be substituted with an alkyl group or an aryl group is preferable. In this case, the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms (e.g., methyl group, t-butyl group, etc.), and the aryl group is preferably an aryl groupThe heteroaryl group is preferably a triazine group, a carbazolyl group (e.g., 2-carbazolyl group, 3-carbazolyl group, 9-carbazolyl group), a pyrimidinyl group, a pyridyl group, a dibenzofuranyl group or a dibenzothiophenyl group. Specific examples include: phenyl, biphenyl, diphenyltriazinyl, carbazolyltriazinyl, monophenylpyrimidinyl, diphenylpyrimidinyl, carbazolyltriazinyl, pyridyl, dibenzofuranyl and dibenzothienyl.
Y 1 Etc. are each independently = C (-R) -or = N-, at least one = N-. Y is 1 ～Y 6 May be = N-. Preferably Y 1 And Y 6 Is = N- (ring a is a pyrimidine ring), Y 1 Or Y 6 Is = N- (ring a is a pyridine ring), Y 2 And Y 5 Is = N- (ring b and ring c are pyridine rings), Y 3 And Y 4 Is = N- (ring b and ring c are pyridine rings), Y 2 ～Y 5 Is = N- (ring b and ring c are pyrimidine rings), Y 1 、Y 3 、Y 4 And Y 6 Is = N- (ring a is a pyrimidine ring, and rings b and c are pyridine rings), Y 1 、Y 2 、Y 5 And Y 6 Is = N- (ring a is a pyrimidine ring, and rings b and c are pyridine rings), Y 1 ～Y 6 Is = N- (ring a, ring b and ring c are pyrimidine rings), Y 2 Or Y 5 Is = N- (b ring or c ring is pyridine ring).
In addition to the above = N-arrangement relationship, X is preferably used 1 And X 2 The polycyclic aromatic compound having a partial structure represented by any one of the following formulae is preferred for > O.
[ 76]
Figure BDA0003858194960000731
In particular, a polycyclic aromatic compound containing a partial structure represented by the formula (EH-1 b-N1) has a higher E than a structure having no N S1 High E T1 Small Δ E S1T1 。
Specific examples of the polycyclic aromatic compound represented by the formula (EH-1 b) are shown below.
[ solution 77]
Figure BDA0003858194960000741
[ solution 78]
Figure BDA0003858194960000751
[ solution 79]
Figure BDA0003858194960000761
[ solution 80]
Figure BDA0003858194960000771
[ solution 81]
Figure BDA0003858194960000781
[ solution 82]
Figure BDA0003858194960000791
Among these, preferred are EH-1-1 to EH-1-4, EH-1-10, EH-1-21 to EH-1-25, EH-1-32, EH-1-33, EH-1-51 to EH-1-59, EH-1-61, EH-1-66, EH-1-68, EH-1-71, EH-1-72, EH-1-90, EH-1-100, EH-1-101, EH-1-104, EH-1-115, EH-1-117, EH-1-120, EH-1-122, EH-1-123, EH-1-127 to EH-1-130.
[ combination of hole-transporting host Material and Electron-transporting host Material ]
The combination of the hole-transporting host material and the electron-transporting host material is selected according to the HOMO, LUMO, and excited triplet energy of the hole-transporting host material, the electron-transporting host material, and the dopant material.
Regarding the HOMO and LUMO, a combination is selected in which the HOMO (HH) of the hole transporting host material is shallower than the HOMO (EH) of the electron transporting host material and the LUMO (EH) of the electron transporting host material is deeper than the LUMO (HH) of the hole transporting host material, more specifically, a combination is preferred in which the HOMO (HH) is shallower by 0.10eV or more than the HOMO (EH) and the LUMO (HH) is deeper by 0.10eV or more than the HOMO (EH), more preferably a combination is preferred in which the HOMO (HH) is shallower by 0.20eV or more than the HOMO (EH) and the LUMO (HH) is deeper by 0.20eV or more than the HOMO (EH), still more preferably a combination is shallower by 0.25eV or more than the HOMO (EH) and the LUMO (HH) is deeper by 0.25eV or more than the HOMO (EH).
The hole-transporting host material and the electron-transporting host material may be a combination of associates forming an exciplex (exiplex). It is generally known that exciplexes readily form between materials having relatively deep LUMO levels and materials having shallow HOMO levels. The interaction between the hole-transporting host material and the electron-transporting host material, specifically whether or not an exciplex is formed, can be determined by: a single-layer film including only a hole-transporting host material and an electron-transporting host material was formed under the same conditions as those for forming the light-emitting layer, and the emission spectrum (fluorescence spectrum and phosphorescence spectrum) was measured and compared with the emission spectrum obtained by separately displaying the hole-transporting host material and the electron-transporting host material. The determination can be made by: the spectrum of the mixed film containing the hole-transporting host material and the electron-transporting host material shows a light-emitting wavelength different from both the spectrum of the film of the hole-transporting host material and the spectrum of the film of the electron-transporting host material. Specifically, the difference in peak wavelengths of the spectra may be indicated by 10nm or more.
Specific examples of the combination of the hole-transporting host material and the electron-transporting host material in which the exciplex is not formed include the following combinations. In order to satisfy the above physical values of HOMO, LUMO, and excited triplet energy, the hole-transporting host material is preferably a compound having carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolocarbazole, and benzoxazinophenazine as a partial structure, more preferably a compound having carbazole, dibenzofuran, and dibenzothiophene as a partial structure, and even more preferably a compound having carbazole as a partial structure. Similarly, among the electron-transporting host materials, compounds having pyridine, triazine, phosphine oxide, benzofuropyridine, and dibenzooxasilaline as partial structures are preferable, compounds having triazine, phosphine oxide, benzofuropyridine, and dibenzooxasilaline as partial structures are more preferable, and compounds having triazine are even more preferable.
More specifically, the hole-transporting host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92, and HH-1-106 to HH-1-108, and the electron-transporting host material is preferably selected from the group consisting of EH-1-4, EH-1-10, EH-1-21 to EH-1-25, EH-1-32, EH-1-33, EH-1-51 to EH-1-59, EH-1-61, EH-1-71, EH-1-72, EH-1-90, EH-1-100, EH-1-101, EH-1-127, EH-1-123, and EH-1-10. Preferable examples of the combination include a compound HH-1-1 and a compound EH-1-22, a compound HH-1-1 and a compound EH-1-23, a compound HH-1-1 and a compound EH-1-24, a compound HH-1-2 and a compound EH-1-22, a compound HH-1-2 and a compound EH-1-23, a compound HH-1-2 and a compound EH-1-24, and a compound HH-1-1 and a compound EH-1-128.
Specific examples of the combination of the hole-transporting host material and the electron-transporting host material for forming the exciplex include the following combinations. In order to satisfy the physical property values of the HOMO, LUMO, and excited triplet energy, the hole-transporting host material is preferably a compound having carbazole, triarylamine, indolocarbazole, and benzoxazinophenazine as a partial structure, more preferably a compound having triarylamine, indolocarbazole, and benzoxazinophenazine as a partial structure, and still more preferably a compound having triarylamine as a partial structure. Similarly, among the electron-transporting host materials, compounds having pyridine, triazine, phosphine oxide, and benzofuropyridine as partial structures are preferable, compounds having triazine, phosphine oxide, benzofuropyridine, and dibenzooxa-silane as partial structures are more preferable, and compounds having phosphine oxide and triazine are even more preferable.
More specifically, the hole-transporting host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-11, HH-1-12, HH-1-17, HH-1-18, HH-1-23, and HH-1-24, and the electron-transporting host material is preferably selected from the group consisting of EH-1-1 to EH-1-4, EH-1-21 to EH-1-25, EH-1-51 to EH-1-57, EH-1-59, EH-1-66, EH-1-68, EH-1-90, EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130. Preferable examples of the combination include a compound HH-1-1 and a compound EH-1-21, a compound HH-1-2 and a compound EH-1-21, a compound HH-1-12 and a compound EH-1-117, a compound HH-1-1 and a compound EH-1-130, a compound HH-1-33 and a compound EH-1-117, a compound HH-1-48 and a compound EH-1-117, or a compound HH-1-49 and a compound EH-1-117.
In addition, with regard to specific combinations of hole-transporting host materials and electron-transporting host materials, reference may be made to: organic Electronics (Organic Electronics) 66 (2019) 227-24, advanced Functional Materials (Advanced. Functional Materials) 25 (2015) 361-366), advanced Materials (Advanced Materials) 26 (2014) 4730-4734, ACS application Materials and Interfaces (ACS application Materials and Interfaces) 8 (2016) 322016 984-32991, ACS application Materials and Interfaces (ACS 36 zxft 3236, 9806-9810), ACS application Materials and Interfaces (ACS 5262 xzft 5262, 32984-32991), "Journal of Material Chemistry" (C, 2018,6, 8784-8792), "German Applied Chemistry" (Angewante Chemistry International edition), "2018, 57, 12380-12384", "(Advanced Functional Materials) (24, 2014, 3970)," Advanced Materials "(26, 2014, 5684), and" Synthetic Metals "(201, 2015, 49), etc.
< dopant Material >
As the dopant material, a known compound can be used, and can be selected from various materials according to a desired emission color. Specific examples thereof include: phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene and
Figure BDA0003858194960000811
condensed ring derivatives such as benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, distyrylanthracene derivatives or distyrylbenzene derivatives (Japanese patent laid-open No. Hei 1-245087), distyrylarylene derivatives (Japanese patent laid-open No. Hei 2-247278), diazabenzodiindene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, ditrimethylphenylisobenzofuran, bis (2-methylphenyl) isobenzofuran, bis (2-trifluoromethylphenyl) isobenzofuran, phenylisobenzofuran derivatives, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinylcoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxy derivatives, 7-acetoxy derivatives, 3-benzothiazolyl derivatives, 3-benzimidazolyl derivatives, 3-benzoxanthylium derivatives, 3-oxocoumarin derivatives, methoxycoumarin derivatives, rhodamine derivatives, fluorescein derivatives, rhodamine derivatives, cyanine derivatives, rhodamine derivatives, and the like, quinolone derivatives, acridine derivatives, oxazine derivatives, phenyl ether derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1,2,5-thiadiazolopyridine derivatives, pyrromethene derivatives, perinone derivatives, pyrrolopyrrole derivativesThe derivative is selected from the group consisting of squarylium salt derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives, and benzofluorene derivatives.
As the dopant material, polycyclic aromatic compounds containing boron described in international publication nos. 2015/102118, 2018/212169, 2020/162600, and the like are also preferably used. The polycyclic aromatic compound having a boron atom may be a phosphor, or may be a TADF material (thermally active retardation phosphor). The polycyclic aromatic compound having a boron atom is preferably a blue light-emitting compound.
By reducing the energy difference between the excited singlet state and the excited triplet state, reverse intersystem crossing from the excited triplet state to the excited singlet state, which is generally low in transition probability, occurs with high efficiency, and light emission from the singlet state (thermally active delayed fluorescence, TADF) appears. In normal fluorescence emission, 75% of triplet excitons generated by current excitation pass through a thermal deactivation path, and thus cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescence emission, and a highly efficient organic EL device can be realized.
Preferred examples of the polycyclic aromatic compound containing boron include compounds represented by the following formula (12), formula (13), or formula (14).
[ solution 83]
Figure BDA0003858194960000821
Ring A, ring B, ring C and ring D are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,
y is B (boron),
X 1 、X 2 、X 3 and X 4 Independently from each other > O, > N-R, > S or > Se, R of > N-R being a substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl, and R of > N-R being optionally substituted by a linker orA single bond to the A ring, the B ring, the C ring and/or the D ring,
R 1 and R 2 Each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms or a diarylamino group (wherein the aryl group is an aryl group having 6 to 12 carbon atoms),
Z 1 and Z 2 Each independently is a substituent selected from substituent group Z, Z 1 Z can be bonded to the A ring by a connecting group or a single bond 2 Can be bonded to the C ring by a linking group or a single bond, and
at least one hydrogen in the compound represented by formula (12) may be substituted with cyano, halogen, or deuterium.
As a substituent when the aryl ring or the heteroaryl ring in the A ring, the B ring, the C ring and the D ring of the formula (12) is substituted, and Z 1 、Z 2 There may be mentioned substituents selected from substituent group Z.
X in the formula (12) 1 、X 2 、X 3 And X 4 Each independently represents > O, > N-R, > S or > Se, and each R > N-R independently represents an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or an alkyl group having 1 to 6 carbon atoms. As the aryl, heteroaryl, cycloalkyl or alkyl group herein, the description of each substituent may be cited.
In the compound represented by the formula (12), Z is Z from the viewpoint of high TADF properties 1 And Z 2 Preferred is a diphenylamino group which may have a substituent or an N-carbazolyl group which may have a substituent, and more preferred is a diphenylamino group which may have a substituent. As the diphenylamino group which may have a substituent, an unsubstituted diphenylamino group or a diphenylamino group having at least one alkyl group having 1 to 4 carbon atoms is preferable, and an unsubstituted diphenylamino group or a diphenylamino group having at least one methyl group at the m-position or the o-position with respect to N is more preferable. In the aryl ring or heteroaryl ring in the a ring, B ring, C ring and D ring, it is preferable to exclude Z from the viewpoint of ease of synthesis and emission wavelength 1 And Z 2 Alkyl having no substituent or having only carbon number of 1-6 as the otherThe other substituent, more preferably other than Z 1 And Z 2 And has no substituent other than the above.
Examples of the compound represented by formula (12) are shown below.
[ solution 84]
Figure BDA0003858194960000831
[ solution 85]
Figure BDA0003858194960000841
[ solution 86]
Figure BDA0003858194960000851
[ solution 87]
Figure BDA0003858194960000861
In the formulae (13) and (14),
A 11 ring, A 21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 Ring, and C 31 Each ring is independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,
Y 11 、Y 21 、Y 31 is B (boron),
X 11 、X 12 、X 21 、X 22 、X 31 and X 32 Independently from each other > O, > N-R, > S or > Se, R of > N-R being a substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl, and R of > N-R being optionally linked to A by a linker or a single bond 11 Ring, A 21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 A ring,And/or C 31 The bond of the ring is bonded to the ring,
at least one hydrogen in the compounds represented by formula (13) and formula (14) may be substituted with cyano, halogen, or deuterium.
A as formula (13) and formula (14) 11 Ring, A 21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 Ring, and C 31 Substituent when aryl ring or heteroaryl ring in ring is substituted and Z 1 、Z 2 There may be mentioned substituents selected from substituent group Z.
X in the formulae (13) and (14) 11 、X 12 、X 21 、X 22 、X 31 And X 32 Each independently represents > O, > N-R, > S or > Se, and each R > N-R independently represents an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or an alkyl group having 1 to 6 carbon atoms.
Examples of the compound represented by formula (13) or formula (14) are shown below.
[ 88]
Figure BDA0003858194960000862
Figure BDA0003858194960000871
[ solution 89]
Figure BDA0003858194960000881
In the light-emitting layer, it is preferable that the polycyclic aromatic compound of the present invention is used as a host material, and a phosphorescent material or a TADF material (thermally active retardation phosphor) is used as a dopant material. The phosphorescent material or TADF material may be included in the light emitting layer as an emission dopant or may be included in the light emitting layer as an auxiliary dopant.
[ phosphorescent Material ]
Phosphorescent materials utilize intramolecular spin-orbit interactions (heavy atom effect) caused by metal atoms to obtain light emission from a triplet state. As such a phosphorescent material, for example, a luminescent metal complex can be used. Examples of the luminescent metal complex include compounds represented by the following formula (B-1) and the following formula (B-2).
[ solution 90]
Figure BDA0003858194960000891
In the formula (B-1), M is at least one selected from the group consisting of Ir, pt, au, eu, ru, re, ag and Cu, n is an integer of 1 to 3, and each of "X-Y" is independently a bidentate ligand.
In the formula (B-2), M is at least one selected from the group consisting of Pt, re and Cu, and "W-X-Y-Z" is a tetradentate ligand.
In the formula (B-1), M is preferably Ir and n is preferably 3 from the viewpoint of efficiency and lifetime.
In the formula (B-2), M is preferably Pt from the viewpoint of efficiency and lifetime.
The ligand (X-Y) in the formula (B-1) has at least one ligand selected from the group consisting of the following. The ligand (W-X-Y-Z) in the formula (B-2) has at least one ligand selected from the group consisting of the following as a part thereof.
[ solution 91]
Figure BDA0003858194960000901
In the formula (I), the compound is shown in the specification,
bonded to the central metal M at- -,
y is independently BR e 、NR e 、PR e 、O、S、Se、C＝O、S＝O、SO 2 、CR e R f 、SiR e R f Or GeR e R f ，
The aromatic carbons C-H in the ring may each independently be substituted with N,
R e and R f Optionally condensed or bonded to form a ring,
R a 、R b 、R c and R d Each independently unsubstituted or substituted to 1 to the maximum number capable of substitution,
R a 、R b 、R c 、R d 、R e and R f Each independently hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, mercapto, or combinations thereof, wherein R is hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, mercapto, or combinations thereof a 、R b 、R c And R d Any two adjacent substituents in (b) may form a ring by condensation or bonding, or may form a multidentate ligand (ligand).
Examples of the compound represented by the formula (B-1) include: ir (ppy) 3 、Ir(ppy) 2 (acac)、Ir(mppy) 3 、Ir(PPy) 2 (m-bppy)、BtpIr(acac)、Ir(btp) 2 (acac)、Ir(2-phq) 3 、Hex-Ir(phq) 3 、Ir(fbi) 2 (acac), fac-Tris (2- (3-p-xylyl) phenyl) pyridine iridium (III) (fac-Tris (2- (3-p-xylyl) phenyl) pyridine iridium (III)), eu (dbm) 3 (Phen)、Ir(piq) 3 、Ir(piq) 2 (acac)、Ir(Fliq) 2 (acac)、Ir(Flq) 2 (acac)、Ru(dtb-bpy) 3 -2(PF 6 )、Ir(2-phq) 3 、Ir(BT) 2 (acac)、Ir(DMP) 3 、Ir(Mphq) 3 IR(phq) 2 tpy、fac-Ir(ppy) 2 Pc、Ir(dp)PQ 2 、Ir(Dpm)(Piq) 2 、Hex-Ir(piq) 2 (acac)、Hex-Ir(piq) 3 、Ir(dmpq) 3 、Ir(dmpq) 2 (acac), FPQIrpic, and the like.
Examples of the compound represented by the formula (B-1) include the following compounds in addition to the above compounds.
[ solution 92]
Figure BDA0003858194960000911
[ solution 93]
Figure BDA0003858194960000921
[ solution 94]
Figure BDA0003858194960000931
Furthermore, iridium complexes described in Japanese patent laid-open No. 2006-089398, japanese patent laid-open No. 2006-080419, japanese patent laid-open No. 2005-298483, japanese patent laid-open No. 2005-097263, japanese patent laid-open No. 2004-111379, US patent application laid-open No. 2019/0051845, and the like, or platinum complexes described in Advanced Materials (Advanced Materials) (26, 7116-7121), natural Asia Materials (NPG Asia Materials) (13, 53 (2021)), "Applied physical express Letters (117, 253301 (2020))," Light Emitting Diode-Empirical characteristics expansion and latest technical expansion (platinum-emissive elements) and latest technical expansion (5) thereof may also be used.
[ thermally active type retardation phosphor used as an auxiliary dopant ]
The "thermally active type delayed phosphor" refers to a compound that absorbs thermal energy, generates reverse intersystem crossing from a lowest excited triplet state to a lowest excited singlet state, and is radioactively inactivated from the lowest excited singlet state, thereby being capable of radioactively delaying fluorescence. The "thermally active delayed fluorescence" includes the case where a higher-order triplet state passes through in the process of excitation from the lowest excited triplet state to the lowest excited singlet state. For example, there may be cited a paper published by munkman (Monkman) et al at the university of Du Lun (Durham) (7, natural-COMMUNICATIONS (NATURE communiquons), DOI: 10.1038/ncomms 13680), a paper published by sabia et al (Hosokai et al), a Scientific progress (Science advans, science. Adv.) (2017 3e 1603282), a paper published by zokukou et al, kyoto et al (7, DOI. For example, regarding a sample containing a target compound, the target compound can be judged to be a "thermally active type delayed phosphor" from the fact that a slow fluorescence component is observed when the fluorescence lifetime is measured at 300K. The slow fluorescence component herein refers to a component having a fluorescence lifetime of 0.1 μ sec or more. The fluorescence lifetime can be measured, for example, using a fluorescence lifetime measuring apparatus (C11367-01, manufactured by Hamamatsu Photonics corporation).
The "thermally active type retardation phosphor" can function as an auxiliary dopant that assists in the emission of the emission dopant.
In the following description, an organic electroluminescent element using a thermally active retardation phosphor as an auxiliary dopant is sometimes referred to as a "TAF element" (TADF assisted Fluorescence (TADF) element).
The "host compound" in the TAF device refers to a compound having a lower excited singlet level determined from a shoulder on the short wavelength side of the peak of the fluorescence spectrum, which is higher than the lower excited singlet levels of the assist dopant and the emissive dopant.
Fig. 2 shows an energy level diagram of a light emitting layer of a TAF element using a general fluorescent dopant for an Emitting Dopant (ED). In the figure, the Energy level of the ground state of the host is E (1,G), the lowest excited singlet level of the host determined from the shoulder on the short-wavelength side of the Fluorescence spectrum is E (1, s, sh), the lowest excited triplet level of the host determined from the shoulder on the short-wavelength side of the Fluorescence spectrum is E (1, t, sh), the Energy level of the ground state of the auxiliary dopant is E (2,G), the lowest excited singlet level of the auxiliary dopant determined from the shoulder on the short-wavelength side of the Fluorescence spectrum is E (2, s, sh), the lowest excited triplet level of the auxiliary dopant determined from the shoulder on the short-wavelength side of the phosphorescence spectrum is E (2, t, sh), the Energy level of the ground state of the emitting dopant is E (3,G), the lowest excited singlet level of the emitting dopant determined from the shoulder on the short-wavelength side of the Fluorescence spectrum is E (3, s, sh), the Energy level of the emitting dopant is E (3, E + and the emission Energy of the electron Transfer is E + and the emission Energy of the emission dopant is E + and the emission Energy of the emission is E + and the emission of the emission dopant. In the TAF device, when a general fluorescent dopant is used as an Emitting Dopant (ED), the energy of Up-Conversion (Up Conversion) from the auxiliary dopant is transferred to the lowest excited singlet level E (3, s, sh) of the emitting dopant and light is emitted. However, a part of the lowest excited triplet level E (2, t, sh) on the auxiliary dopant is shifted to the lowest excited triplet level E (3, t, sh) of the emitting dopant, or intersystem crossing from the lowest excited singlet level E (3, s, sh) to the lowest excited triplet level E (3, t, sh) occurs on the emitting dopant, followed by thermal deactivation to the ground state E (3,G). Due to the path, a part of the energy is not used for light emission, and waste of energy occurs.
On the other hand, for example, in a TAF element in which a compound represented by formula (12), formula (13), or formula (14) is used as an emitting dopant, energy efficiency of migration from an auxiliary dopant to the emitting dopant can be favorably used for light emission, and thus high light emission efficiency can be achieved. The reason for this is presumed to be the following light emission mechanism.
Fig. 3 shows a preferable energy relationship in the organic electroluminescent element of this embodiment. In the organic electroluminescent element of this embodiment, the compound having a boron atom as an emission dopant has a high lowest excited triplet level E (3,t, sh). Therefore, in the case where the lowest excited singlet energy up-converted by the auxiliary dopant is intersystem crossing to the lowest excited triplet level E (3,t, sh), for example, by the emitting dopant, the lowest excited triplet level E (2,t, sh) on the emitting dopant is also up-converted or recovered to the auxiliary dopant (thermally active type delayed phosphor). Therefore, the generated excitation energy can be used for light emission without waste. Further, it is expected that by assigning the functions of up-conversion and light emission to two kinds of molecules whose respective functions are highlighted, the retention time of high energy is reduced, and the load on the compound is reduced.
In this embodiment, the polycyclic aromatic compound of the present invention is preferably used as the host compound.
From the viewpoint of promoting but not inhibiting the generation of TADF in the light-emitting layer, the lowest excited triplet level E (1, t, sh) of the host compound, which is determined from a shoulder on the short wavelength side of the peak of the phosphorescence spectrum, is preferably higher than the lowest excited triplet levels E (2, t, sh) and E (3, t, sh) of the emissive dopant or the assist dopant having the highest lowest excited triplet level in the light-emitting layer, and specifically, the lowest excited triplet level E (1, t, sh) of the host compound is preferably 0.01eV or more, more preferably 0.03eV or more, and still more preferably 0.1eV or more, as compared with E (2, t, sh) and E (3, t, sh). In addition, a compound having TADF activity may also be used as the host compound.
The thermally active retardation phosphor (TADF compound) used in the TAF element is preferably a donor-acceptor type thermally active retardation phosphor (D-a type TADF compound) as follows: it is designed to localize the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) within a molecule using an electron donating substituent called donor and an electron accepting substituent called acceptor to produce efficient reverse interbody crossing.
Here, the "electron donating substituent" (donor) refers to a substituent and a partial structure locally existing in the HOMO in the molecule of the thermally active retardation phosphor, and the "electron accepting substituent" (acceptor) refers to a substituent and a partial structure locally existing in the LUMO in the molecule of the thermally active retardation phosphor.
Generally, a thermally active retardation phosphor using a donor or acceptor has a large Spin Orbit Coupling (SOC) and a small exchange interaction between HOMO and LUMO, Δ E, due to the structure ST Small and therefore very fast reverse inter-system crossing speeds can be achieved. On the other hand, a thermally active type delayed phosphor using a donor or an acceptor has a large structural relaxation in an excited state (in a molecule, since a stable structure is different between a ground state and an excited state, when a transition from the ground state to the excited state occurs by an external stimulus, the structure is changed to a stable structure in the excited state thereafter), and provides a broad emission spectrum, and thus when used as a light emitting material, there is a possibility that the color purity is lowered. However, by using a thermally active type retardation phosphor using a donor or an acceptor together with an appropriate emission dopant such as a compound represented by formula (12), formula (13), or formula (14) as an auxiliary dopant, high color purity can be provided.
As the thermally active type retardation phosphor in the TAF element, for example, a compound in which a donor and an acceptor are bonded directly or via a spacer can be used. Examples of the electron donating group (donor structure) and the electron accepting group (acceptor structure) used in the thermally active retardation phosphor of the present invention include the structures described in "Materials Chemistry of Materials" (2017, 29, 1946-1963). Examples of the structure of the applicator include: carbazole, dimethylcarbazole, di-t-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenylindolinocarbazole, phenylbicarbazole, bicarbazole, tercarbazole (tercarbazole), diphenylcarbazolylamine, tetraphenylcarbazolylamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis (t-butylphenyl) amine, N1- (4- (diphenylamino) phenyl) -N4, N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridine diamine, tetramethyl-dihydro-indenocridine, and diphenyl-dihydrodibenzoazasilaline. Examples of acceptor structures include: sulfonylbenzophenones, benzophenones, phenylenebis (phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile, benzenetricarbonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis (thiazole), benzoxazole, benzobis (oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxide, dimethylanthrone, anthracenedione, 5H-cyclohepta [1,2-b:5,4-b' ] bipyridine, fluorenedicarbonitrile, triphenyltriazine, pyrazinedicarboxonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, bis (phenylsulfonyl) benzene, dimethylthioxanthene dioxide, thianthrene tetraoxide and tris (dimethylphenyl) borane. In particular, the compound having a thermally active delayed fluorescence in the TAF element is preferably a compound having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone as a partial structure.
The compound used as an auxiliary dopant for the light-emitting layer in the TAF element is a thermally active retardation phosphor, and is preferably a compound whose emission spectrum overlaps at least a part of the absorption peak of the emitting dopant.
< Electron injection layer, electron transport layer in organic electroluminescent element >
The electron injection layer 107 functions to efficiently inject electrons transferred from the cathode 108 into the light-emitting layer 105 or the electron transport layer 106. The electron transport layer 106 functions to efficiently transport electrons injected from the cathode 108 or electrons injected from the cathode 108 through the electron injection layer 107 to the light-emitting layer 105. The electron transporting layer 106 and the electron injecting layer 107 are formed by laminating and mixing one or more kinds of electron transporting/injecting materials, or are formed by mixing an electron transporting/injecting material and a polymer binder.
The electron injection/transport layer is a layer that is responsible for injecting electrons from the cathode and transporting the electrons, and is preferably a layer that has high electron injection efficiency and transports the injected electrons efficiently. Therefore, a substance having a high electron affinity, a high electron mobility, and excellent stability is preferable, and impurities that become traps are less likely to be generated during production and use. However, when a balance between transport of holes and transport of electrons is considered, if a function of efficiently preventing holes from the anode from flowing to the cathode side without being recombined is mainly exerted, even if the electron transport ability is not so high, the effect of improving the light emission efficiency is obtained as well as the effect of a material having a high electron transport ability. Therefore, the electron injection/transport layer in this embodiment mode may also include a function of a layer that can efficiently prevent hole transfer.
The material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107 can be selected and used as desired from compounds conventionally used as electron transport compounds in photoconductive materials, and known compounds used in electron injection layers and electron transport layers of organic EL devices. The polycyclic aromatic compound of the present invention is also preferably used as a material for an electron transporting layer.
The material used for the electron transport layer or the electron injection layer preferably contains at least one compound selected from the following compounds: a compound containing an aromatic ring or a heteroaromatic ring containing at least one atom selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus; pyrrole derivatives and condensed ring derivatives thereof; and a metal complex having electron-accepting nitrogen. Specifically, there may be mentioned: aromatic ring derivatives of condensed ring systems such as naphthalene and anthracene, styrene aromatic ring derivatives represented by 4,4' -bis (diphenylvinyl) biphenyl, perinone derivatives, coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, phosphine oxide derivatives, arylnitrile derivatives, and indole derivatives. Examples of the metal complex having electron-accepting nitrogen include: and hydroxyoxazole complexes such as hydroxyphenyl oxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials may be used alone or in combination with different materials.
Specific examples of the other electron transport compound include: pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis [ (4-tert-butylphenyl) 1,3,4-oxadiazolyl ] phenylene) and the like), thiophene derivatives, triazole derivatives (N-naphthyl-2,5-diphenyl-1,3,4-triazole and the like), thiadiazole derivatives, metal complexes of 8-hydroxyquinoline derivatives, hydroxyquinoline metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzoxazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (2,2 '-bis (benzo [ h ] quinolin-2-yl) -9,9' -spirobifluorene and the like), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (tris (N-phenylbenzimidazole-2-yl) benzene, benzo [ h ] quinolin-2-yl ] benzene, oligoquinoline derivatives, benzo [ 4264 '-quinoline ] pyridine derivatives (4264' -tris- (3-zzylphenyl) pyridine derivatives, 4234 '-terphenyl) pyridine derivatives, tris (3' -terphenyl-naphthyridine derivatives and the like), terphenyl-pyridine derivatives (3-4232-pyridine derivatives and the like), terphenyl-naphthalene derivatives, 4234-pyridine derivatives and the like), and the like, aldazine derivatives, carbazole derivatives, indole derivatives, phosphine oxide derivatives, bisstyryl derivatives, and the like.
In addition, a metal complex having electron-accepting nitrogen may also be used, and examples thereof include: hydroxyoxazole complexes such as hydroxyquinoline metal complexes and hydroxyphenyl oxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.
The materials can be used alone or in admixture with different materials.
Among the above materials, preferred are borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and hydroxyquinoline-based metal complexes.
The electron transport layer or the electron injection layer may further contain a substance capable of reducing a material forming the electron transport layer or the electron injection layer. As long as the reducing substance has a certain degree of reducibility, various substances can be used, and for example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals can be preferably used.
Preferable reducing substances include alkali metals such as Na (work function 2.36 eV), K (work function 2.28 eV), rb (work function 2.16 eV), and Cs (work function 1.95 eV), and alkaline earth metals such as Ca (work function 2.9 eV), sr (work function 2.0 to 2.5 eV), and Ba (work function 2.52 eV), and particularly preferable substances have a work function of 2.9eV or less. Among these, the reducing substance is more preferably an alkali metal of K, rb or Cs, still more preferably Rb or Cs, and most preferably Cs. These alkali metals have particularly high reducing power, and by adding a relatively small amount of the alkali metals to a material forming the electron transporting layer or the electron injecting layer, improvement in light emission luminance or prolongation in the organic EL element can be achieved. In addition, as the reducing substance having a work function of 2.9eV or less, a combination of two or more of these alkali metals is also preferable, and a combination including Cs, for example, a combination of Cs and Na, cs and K, cs and Rb, or Cs and Na and K is particularly preferable. By including Cs, the reducing ability can be efficiently exerted, and by adding Cs to a material for forming an electron transporting layer or an electron injecting layer, improvement in light emission luminance or prolongation in life of the organic EL element can be achieved.
< cathode in organic electroluminescent element >
The cathode 108 functions to inject electrons into the light-emitting layer 105 through the electron injection layer 107 and the electron transport layer 106.
The material forming the cathode 108 is not particularly limited as long as it can efficiently inject electrons into the organic layer, and the same material as the material forming the anode 102 can be used. Among them, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, and alloys thereof (e.g., magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys such as lithium fluoride and aluminum) are preferable. In order to improve the electron injection efficiency to improve the element characteristics, lithium, sodium, potassium, cesium, calcium, magnesium, or an alloy containing these low work function metals is effective. However, in general, these low work function metals are most often unstable in the atmosphere. In order to improve this, for example, a method of doping a minute amount of lithium, cesium, or magnesium into an organic layer and using an electrode having high stability is known. As the other dopant, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide can be used. However, the present invention is not limited to these examples.
Further, the following are preferable examples: metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, alloys using these metals, inorganic substances such as silicon dioxide, titanium dioxide, and silicon nitride, polyvinyl alcohol, vinyl chloride, and hydrocarbon-based polymer compounds are laminated to protect the electrodes. The method for producing these electrodes is not particularly limited as long as conduction can be achieved by resistance heating, electron beam evaporation, sputtering, ion plating, coating, or the like.
< method for manufacturing organic electroluminescent element >
Each layer constituting the organic EL element can be formed by forming a material to be each layer into a thin film by a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, printing, spin coating, casting, or coating. The film thickness of each layer formed in the above-described manner is not particularly limited, and may be appropriately set according to the properties of the material, but is usually in the range of 2nm to 5000 nm. The film thickness can be measured by a quartz oscillation type film thickness measuring apparatus or the like. When a thin film is formed by a vapor deposition method, the vapor deposition conditions vary depending on the type of material, the target crystal structure and association structure of the film to be formed, and the like. The deposition conditions are preferably set to +50 ℃ to +400 ℃ in a boat heating temperature and 10 degrees of vacuum -6 Pa～10 -3 Pa, a deposition rate of 0.01nm/sec to 50nm/sec, a substrate temperature of-150 ℃ to +300 ℃, and a film thickness of 2nm to 5 μm.
When a dc voltage is applied to the organic EL element obtained as described above, the anode may be applied with a + polarity and the cathode may be applied with a-polarity, and when a voltage of about 2V to 40V is applied, light emission can be observed from the transparent or translucent electrode side (anode or cathode, or both). In addition, the organic EL element emits light even when a pulse current or an alternating current is applied thereto. In addition, the waveform of the applied alternating current may be arbitrary.
Next, as an example of a method for manufacturing an organic EL element, a method for manufacturing an organic EL element including an anode, a hole injection layer, a hole transport layer, a light-emitting layer including a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode will be described.
< vapor deposition method >
An anode is formed by forming a thin film of an anode material on an appropriate substrate by vapor deposition or the like, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A target organic EL element is obtained by co-evaporating a host material and a dopant material on the thin film to form a thin film as a light-emitting layer, forming an electron transport layer and an electron injection layer on the light-emitting layer, and further forming a thin film containing a substance for a cathode as a cathode by an evaporation method or the like. In the production of the organic EL element, the order of production may be reversed, and the organic EL element may be produced by using a cathode, an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, a hole injection layer, and an anode in this order.
< Wet film Forming method >
A low-molecular-weight compound capable of forming each organic layer of an organic EL element is prepared as a liquid composition for forming an organic layer, and a wet film-forming method is performed using the composition. In the case where an appropriate organic solvent for dissolving the low-molecular compound is not present, the composition for forming an organic layer may be prepared from a high-molecular compound which is polymerized together with another monomer or main chain polymer having a solubility function as a reactive compound obtained by substituting a reactive substituent in the low-molecular compound, or the like.
In general, a wet film formation method forms a coating film by passing through a coating step of coating a substrate with an organic layer forming composition and a drying step of removing a solvent from the coated organic layer forming composition. In the case where the polymer compound has a crosslinkable substituent (also referred to as a crosslinkable polymer compound), the polymer compound is further crosslinked by the drying step to form a crosslinked polymer. Depending on the coating process, a method using a spin coater is called a spin coating method, a method using a slit coater is called a slit coating method, a method using a plate is called a gravure, offset, reverse offset, or flexo printing method, a method using an ink jet printer is called an ink jet method, and a method of spraying in a mist form is called a spray method. The drying step may be carried out by air drying, heating, drying under reduced pressure, or the like. The drying step may be performed only once, or may be performed a plurality of times by using different methods or conditions. Alternatively, for example, different methods may be used in combination as in the case of calcination under reduced pressure.
The wet film formation method refers to a film formation method using a solution, and examples thereof include a partial printing method (ink jet method), a spin coating method, a casting method, and a coating method. Unlike the vacuum deposition method, the wet film formation method can form a film under atmospheric pressure without using an expensive vacuum deposition apparatus. In addition, the wet film formation method can be performed in a large area or in a continuous manner, which leads to a reduction in manufacturing cost.
On the other hand, in the case of a wet film formation method, lamination may be difficult as compared with a vacuum deposition method. In the case of producing a laminated film by a wet film formation method, it is necessary to prevent the dissolution of the lower layer by the composition of the upper layer, and to use a composition whose solubility is controlled, a cross-linking of the lower layer, and an Orthogonal solvent (mutually insoluble solvent), or the like. However, even with these techniques, it is sometimes difficult to apply the wet film formation method to the coating of all the films.
Therefore, the following method is generally employed: only a plurality of layers were formed by a wet film formation method, and the remaining layers were formed by a vacuum evaporation method, thereby producing an organic EL element.
For example, a part of the procedure for producing an organic EL element by applying a wet film formation method is shown below.
(procedure 1) deposition of Anode by vacuum deposition
(procedure 2) film formation by Wet film formation method of composition for Forming hole injection layer containing Material for hole injection layer
(program 3) film formation by Wet film formation method of composition for Forming hole transport layer containing Material for hole transport layer
(procedure 4) film formation by Wet film formation method of light-emitting layer-Forming composition containing host Material and dopant Material
(program 5) deposition of Electron transport layer by vacuum deposition
(program 6) deposition of an Electron injection layer by vacuum deposition
(program 7) film formation of cathode by vacuum vapor deposition
By going through the procedure, an organic EL element including an anode/a hole injection layer/a hole transport layer/a light emitting layer containing a host material and a dopant material/an electron transport layer/an electron injection layer/a cathode can be obtained.
Of course, the electron transport layer and the electron injection layer may be formed by a wet film formation method using a composition for layer formation containing a material for the electron transport layer and a material for the electron injection layer, respectively. In this case, it is preferable to use a method of preventing the light-emitting layer of the lower layer from dissolving or a method of forming a film from the cathode side in reverse to the above procedure.
< other film formation method >
For forming a film of the composition for forming an organic layer, a Laser Induced Thermal Imaging (LITI) method may be used. LITI is a method of performing thermal vapor deposition of a compound attached to a substrate by using a laser, and the composition for forming an organic layer can be used for a material to be coated on a substrate.
< optional Process >
Before and after each step of film formation, an appropriate treatment step, cleaning step and drying step may be added as appropriate. Examples of the treatment step include: exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment with an appropriate solvent, heat treatment, and the like. Further, a series of steps for producing banks (banks) can be exemplified.
Photolithography may be used in the fabrication of the banks. As the bank material that can be used for photolithography, a positive resist material and a negative resist material can be used. Further, a printing method capable of forming a pattern such as an ink jet method, gravure offset printing, reverse offset printing, screen printing, or the like may be used. At this time, a permanent resist material may also be used.
< composition for forming organic layer used in Wet film Forming method >
The composition for forming an organic layer is obtained by dissolving a low-molecular compound capable of forming each organic layer of an organic EL element or a high-molecular compound obtained by polymerizing the low-molecular compound in an organic solvent. For example, the composition for forming a light-emitting layer contains a polycyclic aromatic compound (or a polymer compound thereof) as a first component, which is at least one dopant material, at least one host material as a second component, and at least one organic solvent as a third component. The first component functions as a dopant component of the light-emitting layer obtained from the composition, and the second component functions as a host component of the light-emitting layer. The third component functions as a solvent for dissolving the first component and the second component in the composition, and obtains a smooth and uniform surface shape by utilizing a controlled evaporation rate of the third component itself at the time of application.
< organic solvent >
The composition for forming an organic layer contains at least one organic solvent. The film forming property, the presence or absence of defects in the film, the surface roughness, and the smoothness can be controlled and improved by controlling the evaporation rate of the organic solvent during film formation. In addition, when the film is formed by the ink jet method, the meniscus (meniscus) stability at the pin hole of the ink jet head can be controlled, and the ejection property can be controlled/improved. In addition, by controlling the drying rate of the film and the orientation of the derivative molecules, the electrical characteristics, light emission characteristics, efficiency, and lifetime of an organic EL element having an organic layer obtained from the composition for forming an organic layer can be improved.
The organic solvent is removed from the coating film by a drying step such as vacuum, reduced pressure, or heating after film formation. In the case of heating, from the viewpoint of improving coating film formability, it is preferable to perform the heating at a glass transition temperature (Tg) of at least one of the solutes) +30 ℃. From the viewpoint of reducing the residual solvent, it is preferable to heat at least one solute at a glass transition temperature (Tg) of-30 ℃. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is sufficiently removed because the film is thin. Further, the drying may be performed a plurality of times at different temperatures, or a plurality of drying methods may be used in combination.
(2) Specific examples of organic solvents
Examples of the organic solvent used in the composition for forming an organic layer include: an alkylbenzene solvent, a phenyl ether solvent, an alkyl ether solvent, a cyclic ketone solvent, an aliphatic ketone solvent, a monocyclic ketone solvent, a solvent having a diester skeleton, a fluorine-containing solvent, and the like, but the solvent is not limited thereto. The solvents may be used alone or in combination.
< optional component >
The composition for forming an organic layer may contain any component within a range not impairing the properties thereof. Examples of the optional component include a binder and a surfactant.
< composition and Property of composition for Forming organic layer >
The content of each component in the composition for forming an organic layer is determined in consideration of good solubility, storage stability and film forming property of each component in the composition for forming an organic layer, good film quality of a coating film obtained from the composition for forming an organic layer, good ejection property in the case of using an inkjet method, and good electrical characteristics, light emitting characteristics, efficiency and lifetime of an organic EL element having an organic layer formed using the composition.
The composition for forming an organic layer can be produced by appropriately selecting the above components by a known method, and stirring, mixing, heating, cooling, dissolving, dispersing, or the like. After the preparation, filtration, degassing (also referred to as degassing), ion exchange treatment, inert gas substitution/encapsulation treatment, and the like may be optionally performed.
< application example of organic electroluminescent element >
In addition, the present invention is also applicable to a display device including an organic EL element, an illumination device including an organic EL element, or the like.
A display device or an illumination device including an organic EL element can be manufactured by a known method such as connecting the organic EL element of this embodiment to a known driving device, and can be driven by a known driving method such as dc driving, pulse driving, or ac driving.
Examples of the display device include: a panel display such as a color flat panel display, a flexible display such as a flexible color organic Electroluminescence (EL) display, and the like (for example, refer to japanese patent laid-open publication nos. 10-335066, 2003-321546, 2004-281086, and the like). Examples of the display mode of the display include a matrix mode and a segment mode. Further, the matrix display and the segment display may coexist in the same panel.
In the matrix, pixels for display are two-dimensionally arranged in a lattice shape, a mosaic shape, or the like, and characters or images are displayed by a set of pixels. The shape or size of the pixel is determined according to the application. For example, in image and character display of a personal computer, a monitor, and a television, a rectangular pixel having a side of 300 μm or less is generally used, and in the case of a large-sized display such as a display screen, a pixel having a side of mm level is used. In the case of monochrome display, pixels of the same color may be arranged, and in the case of color display, pixels of red, green, and blue are arranged in parallel to perform display. In this case, a triangular shape and a striped shape are typical. Also, as a driving method of the matrix, any one of a line-sequential (line-sequential) driving method or an active matrix may be used. The line sequential driving has an advantage of a simple structure, but when the operation characteristics are taken into consideration, the active matrix may be more excellent, and therefore the driving method needs to be used separately depending on the application.
In the segment method (type), a pattern is formed so as to display predetermined information, and the determined region is caused to emit light. Examples thereof include: time and temperature display in a digital clock or a thermometer, operation state display of an audio device or an induction cooker, panel display of an automobile, and the like.
Examples of the illumination device include an illumination device such as an indoor illumination, and a backlight of a liquid crystal display device (see, for example, japanese patent laid-open nos. 2003-257621, 2003-277741, and 2004-119211). Backlights are used mainly for improving visibility of display devices that do not emit light, and are used for liquid crystal display devices, clocks, audio devices, automobile panels, display panels, signs, and the like. In particular, as a backlight for personal computer applications in which thinning is an issue in liquid crystal display devices, considering that thinning is difficult in the conventional method because of including a fluorescent lamp or a light guide plate, the backlight using the light emitting element of the present embodiment has characteristics of thinness and lightweight.
3-2. Other organic devices
The polycyclic aromatic compound of the present invention can be used for the production of an organic field effect transistor, an organic thin film solar cell, or the like, in addition to the organic electroluminescent element.
[ examples ]
The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. First, a synthesis example of the polycyclic aromatic compound will be described below.
Synthesis of Compound (10-1)
[ solution 95]
Figure BDA0003858194960001011
1,2-dibromobenzene 65g, aniline 77g, bis (dibenzylideneacetone) palladium (0) (Pd (d)ba) 2 ) 4.8g of tri-tert-butylphosphonium tetrafluoroborate (tBu) 3 P-HBF 4 ) 4.8g of sodium tert-butoxide (NaOtBu) 79.4g and 650ml of toluene were put in a flask and refluxed for 2 hours while being stirred. After the reaction, the reaction mixture was cooled to room temperature, and water and toluene were added to separate the reaction mixture. Then, the organic layer was purified by silica gel short-path column chromatography (solvent: toluene), and then purified by silica gel column chromatography (solvent: toluene/heptane = 1/1), to obtain an intermediate compound N 1 ,N 2 Diphenylbenzene-1,2-diamine 63.7g.
[ solution 96]
Figure BDA0003858194960001021
Under nitrogen atmosphere, adding N 1 ,N 2 56g of-diphenylbenzene-1,2-diamine, 43.1g of 2-nitrophenylboronic acid, 4.1g of methanesulfonic acid and 1680ml of toluene were placed in a flask equipped with a dean-stark trap and refluxed for 9 hours while being stirred. After the reaction, the reaction solution was cooled to room temperature, refined by a silica gel short-path column (solvent: toluene), and washed with a Solmikus solvent to obtain an intermediate compound, 2- (2-nitrophenyl) -1,3-diphenyl-2,3-dihydro-1H-benzo [ d ] n][1,3,2]48.6g of diazaboropentadine.
[ solution 97]
Figure BDA0003858194960001022
2- (2-Nitrophenyl) -1,3-diphenyl-2,3-dihydro-1H-benzo [ d ] [1,3,2] diazaborine 36g with triphenylphosphine 84.5g and 1,2,4-trichlorobenzene 1800ml were placed in a flask under nitrogen, stirred and refluxed for 8 hours. After the reaction, the solvent was removed by distillation under reduced pressure, followed by purification by silica gel column chromatography (solvent: toluene/heptane = 1/1) and further by washing with a methanol solvent to obtain 3.5g of an intermediate compound, 16-phenyl-10H, 16H-dibenzo [ c, f ] benzo [4,5] [1,3,2] diazaborine-pentalene [1,2-a ] [1,5,2] diazaborine-heptatriene.
[ solution 98]
Figure BDA0003858194960001023
16-phenyl-10H, 169H-dibenzo [ c, f ] benzo [4,5] [1,3,2] diazaborole [1,2-a ] [1,5,2] diazaborene 1.4g, copper 0.5g, potassium carbonate 2.0g, and iodobenzene 35ml were placed in a flask under nitrogen atmosphere, and refluxed for 6 hours while being stirred. After the reaction, the reaction mixture was cooled to room temperature, and the reaction mixture was purified by a silica gel short-path column (solvent: toluene). Then, the resulting extract was purified by silica gel column chromatography (solvent: toluene/heptane = 1/4), and then reprecipitated several times with methanol, followed by sublimation purification to obtain the objective compound (10-1) (0.7 g).
[ solution 99]
Figure BDA0003858194960001031
The structure of the compound of formula (10-1) was confirmed by Mass Spectrometry (MS) spectroscopy and Nuclear Magnetic Resonance (NMR) measurement.
1 H-NMR(CDCl 3 )：δ＝7.97(dd,1H),7.70(d,1H),7.65(dd,1H),7.55(d,1H),7.49～7.42(m,4H),7.38～7.24(m,4H),7.15(dd,1H),7.10～7.01(m,6H),6.63(t,1H),6.55(d,2H)
Further, the glass transition temperature (Tg) of the compound of formula (10-1) was 93.7 ℃.
[ measurement apparatus: dai Mengde (Diamond) Differential Scanning Calorimeter (DSC) (manufactured by Perkin Elmer (PERKIN-ELMER)); the measurement conditions were as follows: cooling rate of 200 deg.C/Min, heating rate of 10 deg.C/Min
Synthesis of Compound (10-49)
[ solution 100]
Figure BDA0003858194960001032
Under nitrogen atmosphere, 16-phenyl-10H, 169H-dibenzo [ c, f ] is mixed]Benzo [4,5][1,3,2]Diazaborole [1,2-a][1,5,2]1.7g of diazaboroheptatriene, 1.24g of 55% sodium hydride (NaH), and 77ml of Dimethylformamide (DMF) were put in a flask and stirred at room temperature for 1 hour. Thereafter, 3.8g of 2-chloro-4,6-diphenyl-1,3,5-triazine was added, followed by stirring at room temperature for 64 hours. After the reaction, water was slowly added while cooling with an ice water bath, and extraction was performed with ethyl acetate. Then, using NH 2 The crude product obtained by distilling the solvent of the organic layer under reduced pressure was purified by silica gel column chromatography (solvent: toluene/heptane =1/2 (volume ratio)), and then reprecipitated several times using solmikus (Solmix) solvent, followed by sublimation purification, to obtain the target compound (10-49) (1.4 g).
[ solution 101]
Figure BDA0003858194960001041
The structure of the compound of formula (10-49) was confirmed by MS spectrum and NMR measurement.
1 H-NMR(CDCl 3 )：δ＝8.35(d,2H),8.32(d,2H),7.97(dd,1H),7.76～7.74(m,2H),7.63(d,1H),7.53～7.33(m,14H),7.20～7.16(m,2H),7.07～7.00(m,3H)
Synthesis of Compound (20-1)
[ solution 102]
Figure BDA0003858194960001042
Under a nitrogen atmosphere, 33.5g of 2-bromo-N, N-diphenylaniline, 19.2g of 2-aminobiphenyl, and palladium (0) (Pd (dba) bis (dibenzylideneacetone) 2 ) 1.8g of tri-tert-butylphosphonium tetrafluoroborate (tBu) 3 P-HBF 4 ) 1.8g of sodium tert-butoxide (NaOtBu) 19.9g and 302ml of toluene were placed in a flaskThe mixture was refluxed for 4 hours while being stirred. After the reaction, the reaction mixture was cooled to room temperature, and water and toluene were added to separate the reaction mixture. Thereafter, the organic layer was purified by silica gel short-path column chromatography (solvent: toluene) and then purified by silica gel column chromatography (solvent: toluene/heptane = 1/2), to obtain an intermediate compound N 1 - ([ 1,1' -biphenyl)]-2-yl) -N 2 ,N 2 Diphenylbenzene-1,2-diamine (39.9 g).
[ solution 103]
Figure BDA0003858194960001043
Under nitrogen atmosphere, putting N 1 - ([ 1,1' -biphenyl)]-2-yl) -N 2 ,N 2 A flask of 16.8g of-diphenylbenzene-1,2-diamine and 420ml of toluene was cooled to-70 ℃ and 16ml of a 2.6M hexane solution of n-butyllithium was added dropwise. After the completion of the dropwise addition, the mixture was stirred at-70 ℃ for 1 hour and at 0 ℃ for 1 hour. Thereafter, the mixture was cooled again to-70 ℃ and a solution of boron tribromide (10.2 g) in heptane was added dropwise. Then, the reaction solution was warmed to room temperature, and stirred at room temperature overnight. Thereafter, the solvent was distilled off under reduced pressure once. To this, 504ml of 1,2-dichlorobenzene, 11.1g of N, N-diisopropylethylamine, and 32.6g of aluminum trichloride were added, and the mixture was stirred at 160 ℃ for 6 hours. The reaction was cooled to room temperature and added to ice-water solution of sodium acetate. Toluene was added thereto for liquid separation. The organic layer was purified by silica gel short-path column chromatography (solvent: toluene) followed by silica gel column chromatography (solvent: toluene/heptane =1/3 (volume ratio)). The crude product obtained was dissolved with toluene, reprecipitated several times with soymilkos (Solmix) and further recrystallized several times from ethyl acetate. Finally, sublimation purification was carried out to obtain the objective compound (20-1) (0.5 g).
[ solution 104]
Figure BDA0003858194960001051
The structure of the compound of formula (20-1) was confirmed by MS spectrum and NMR measurement.
1 H-NMR(CDCl 3 )：δ＝8.64(d,1H),8.58(d,1H),8.30(d,1H),7.70(d,2H),7.63～7.60(m,4H),7.55～7.48(m,6H),7.41～7.37(m,2H),7.27～7.18(m,3H),7.06(d,1H)
Synthesis of Compound (20-17)
[ solution 105]
Figure BDA0003858194960001052
In the synthesis of compound (20-1), N is added 1 - ([ 1,1' -biphenyl)]-2-yl) -N 2 ,N 2 The same procedure was followed except that 16.8g of (E) -diphenylbenzene-1,2-diamine was changed to 20.8g of the compound (Int-20-17) to obtain (0.2 g) of the objective compound (20-17).
[ solution 106]
Figure BDA0003858194960001053
The target compound (20-17) was confirmed by Liquid Chromatography-Mass Spectrometry (LC-MS) at m/z = 575.2284.
Synthesis of Compound (10-33)
[ solution 107]
Figure BDA0003858194960001061
The same procedure was followed except that 35ml of iodobenzene was changed to 168g of compound (Int-I-mCP) in the synthesis of compound (10-1), to obtain the objective compound (10-33) (2.5 g).
[ solution 108]
Figure BDA0003858194960001062
The compound (10-33) as the target compound was confirmed by LC-MS at m/z = 765.3060.
Synthesis of Compound (20-79)
[ solution 109]
Figure BDA0003858194960001063
In the synthesis of compound (20-1), N is added 1 - ([ 1,1' -biphenyl)]-2-yl) -N 2 ,N 2 The same procedure was followed except that 16.8g of-diphenylbenzene-1,2-diamine was changed to 21.0g of compound (Int-20-79), and the amount of the objective compound (20-79) (0.4 g) was obtained.
[ solution 110]
Figure BDA0003858194960001071
The compound (20-79) as the target compound was confirmed by LC-MS at m/z = 740.2866.
Synthesis of Compound (10-82)
[ solution 111]
Figure BDA0003858194960001072
The same procedure was repeated except that 35ml of iodobenzene was changed to 190g of compound (Int-I-DBF-Trz) in the synthesis of compound (10-1), to obtain the objective compound (10-82) (5.1 g).
[ solution 112]
Figure BDA0003858194960001073
The compound (10-82) was confirmed as the target compound by LC-MS at m/z = 756.2810.
By appropriately changing the compound as a raw material, another polycyclic aromatic compound of the present invention can be synthesized by the method according to the above synthesis example.
Then, evaluation of basic properties of the compound of the present invention, and production and evaluation of an organic EL element using the compound of the present invention are described. The application of the compound of the present invention is not limited to the examples shown below, and the film thickness and the constituent material of each layer may be appropriately changed depending on the basic properties of the compound of the present invention.
< evaluation of vapor deposition type organic EL element >
The organic EL elements of examples and comparative examples were fabricated, and the luminance was measured at 1000cd/m 2 External quantum efficiency of (1), and LT50 (at initial luminance of 1000 cd/m) 2 The current density reaches 500cd/m when the motor is continuously driven 2 Time of (d).
< comparative example RS-1 >
A glass substrate (manufactured by Opto Science) having a thickness of 26mm by 28mm by 0.7mm obtained by polishing ITO deposited to a thickness of 200nm by sputtering to a thickness of 50nm was used as a transparent support substrate. The transparent support substrate was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa vacuum deposition (Strand)), and a molybdenum vapor deposition boat and a tungsten vapor deposition boat were set, each of which was filled with HAT-CN, HTL-1, tcTa, new-DABNA, ETL-1, and ET 7.
The following layers are sequentially formed on the ITO film of the transparent support substrate. The vacuum vessel was depressurized to 5X 10 -4 Pa, HAT-CN was first heated and evaporated to form a hole injection layer with a film thickness of 5 nm. Subsequently, the HTL-1 was heated to form a hole transport layer 1 by vapor deposition so that the film thickness became 90nm, and the TcTa was heated to form a hole transport layer 2 by vapor deposition so that the film thickness became 10 nm. Then, ETL-1 and new-DABNA were heated at the same time, and vapor-deposited to a film thickness of 20nm to form a light-emitting layer. The deposition rate was adjusted so that the mass ratio of ETL-1 to new-DABNA became approximately 99 to 1. Subsequently, ETL-1 was heated and vapor-deposited to have a film thickness of 20nm to form an electron transport layer 1, and ET7 was heated and vapor-deposited to have a film thickness of 10nm to form an electron transport layer 2 including two layers. The deposition rate of each layer is 0.01nm/sec to 1 nm/sec. Then, liF is heated and evaporated at a deposition rate of 0.01nm/sec to 0.1 nm/sec so that the film thickness becomes 1nmAfter the plating, aluminum was heated and vapor-deposited to a film thickness of 100nm to form a cathode, thereby obtaining an organic EL element. In this case, the deposition rate of aluminum is adjusted to 1nm/sec to 10 nm/sec.
< examples and comparative examples >
Each element was produced by changing the materials and concentrations of the hole transport layer 2, the light emitting layer, and the electron transport layer 1 of the comparative example to those shown in table 1. In table 1, "host 1" corresponds to a hole-transporting host material, and "host 2" corresponds to an electron-transporting host material. The evaluation results of the respective elements are shown in table 1.
As shown in examples S-1 and S-2, the organic electroluminescent element using the compound of the present invention as a single host exhibited high efficiency and long life as compared with comparative example RS-1. Similarly, as shown in examples D-1 to D-5, the organic electroluminescent element using the compound of the present invention as either of the two main components exhibited high efficiency and long life as compared with comparative example RD-1. The compound of the present invention has a deep HOMO or a shallow LUMO, and high T1 energy and charge transport properties, and therefore can be used as a hole transport layer or an electron transport layer adjacent to a light-emitting layer. Specifically, as shown in examples HD-1 to HD-3, DE-1, E-1 and E-2, and H-1 and H-2, the organic electroluminescent element using the compound of the present invention in the hole transport layer or the charge transport layer adjacent to the light-emitting layer has high efficiency and long life. Further, as shown in examples HD-1 and DE-1, the highest efficiency and the longest lifetime were obtained in the organic electroluminescent element using the compound of the present invention in any two layers of the light-emitting layer and the hole-transporting layer or the electron-transporting layer adjacent to the light-emitting layer. Further, as shown in examples HD-1 to HD-3, since the compound of the present invention has a high T1 energy, it can also be used as a host for a blue TADF dopant or a blue phosphorescent dopant having a high T1.
[ Table 1]
Figure BDA0003858194960001091
Figure BDA0003858194960001092
The chemical structures in table 1 are shown below.
[ solution 113]
Figure BDA0003858194960001101
< comparative example RDT-1 >
A glass substrate (manufactured by Opto Science) having a thickness of 26mm by 28mm by 0.7mm obtained by polishing ITO deposited to a thickness of 200nm by sputtering to a thickness of 50nm was used as a transparent support substrate. The transparent support substrate was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa vacuum deposition (Strand)), and a molybdenum vapor deposition boat and a tungsten vapor deposition boat were respectively placed therein, the molybdenum vapor deposition boat containing HAT-CN, HTL-1, tcTa, ETL-1, and ET7, and the tungsten vapor deposition boat containing LiF and aluminum.
The following layers are sequentially formed on the ITO film of the transparent support substrate. The vacuum vessel was depressurized to 5X 10 -4 Pa, HAT-CN was heated and vapor-deposited to a film thickness of 5nm to form a hole injection layer. Subsequently, the HTL-1 was heated to form a hole transport layer 1 by vapor deposition so that the film thickness became 90nm, and the TcTa was heated to form a hole transport layer 2 by vapor deposition so that the film thickness became 10 nm. Then, ETL-1 and new-DABNA were simultaneously heated and vapor-deposited so that the film thickness became 20nm, thereby forming a light-emitting layer. The deposition rate was adjusted so that the mass ratio of ETL-1 to new-DABNA became approximately 99 to 1. Subsequently, ETL-1 was heated and vapor-deposited to a film thickness of 20nm to form an electron transit layer 1, and ET7 was heated and vapor-deposited to a film thickness of 10nm to form an electron transit layer 2. The deposition rate of each layer is set to 0.01nm/sec to 1 nm/sec. Then, liF is subjected toThe organic EL element can be obtained by heating and performing vapor deposition at a vapor deposition rate of 0.01 nm/second to 0.1 nm/second so that the film thickness becomes 1nm, and then heating aluminum and performing vapor deposition so that the film thickness becomes 100nm to form a cathode. In this case, the deposition rate of aluminum is adjusted to 1nm/sec to 10 nm/sec.
The hole transport layer 2, the light emitting layer, and the electron transport layer 1 of comparative example RDT-1 were changed to the materials and concentrations shown in Table 2, and the devices of examples DT-1 to DT-4 were fabricated.
[ Table 2]
Figure BDA0003858194960001111
The chemical structures of the compounds shown in table 2 are shown below.
[ chemical formula 114]
Figure BDA0003858194960001112
As described above, although some of the compounds of the present invention have been evaluated as excellent materials for organic EL devices, other compounds not evaluated also have the same basic skeleton and have similar structures as a whole, and those skilled in the art can similarly understand that the compounds are excellent materials for organic EL devices.

Claims (18)

1. A polycyclic aromatic compound having a structure containing one or more structural units represented by the following formula (1);
Figure FDA0003858194950000011
in the formula (1), the reaction mixture is,
ring A, ring B and ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,
y is > B-, > P (= O) -or > P (= S) -,
x is > C (-R) X1 ) -, > N-or > Si (-R) X3 )-，
R X1 And R X3 Each independently is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl,
z is > C (-R) Z1 ) 2 、＞N-R Z2 、＞O、＞Si(-R Z3 ) 2 Or is greater than the number of the first electrode wires,
R Z1 、R Z2 and R Z3 Each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, or together with the bonded elements and ring B or ring C, form a ring, wherein two R' s Z1 May be bonded to each other, and two R Z3 Can be bonded to each other and can be bonded to each other,
l is a shortest linking group having 1 to 4 atoms which links the ring A and the ring Y,
l may be bonded to the A ring by a linking group or a single bond,
at least one hydrogen in the structure may be substituted with deuterium, cyano, or halogen.
2. The polycyclic aromatic compound according to claim 1, wherein the structure comprises one of the structural units represented by formula (1).
3. The polycyclic aromatic compound of claim 1 or 2, wherein ring a, ring B and ring C are each a substituted or unsubstituted benzene ring.
4. The polycyclic aromatic compound of any one of claims 1 to 3, wherein L is > C (-R) L1 ) 2 、＞N-R L2 、＞O、＞Si(-R L3 ) 2 、＞S、＞C＝CR L1 2 、＞C＝NR L2 、＞C＝O、＞C＝S、-φ-、-φ-C(-R L1 ) 2 -、-φ-N(-R L2 )-、-φ-O-、-φ-Si(-R L3 ) 2 -、-φ-S-、-φ-C(＝CR L1 2 )-、-φ-C(＝NR L2 ) -, - φ -C (= O) -or- φ -C (= S) -,
R L1 、R L2 and R L3 Each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, two R's bonded to the same element L1 Or R L3 Each of which may be bonded to each other, R L1 At least one of R L2 And R L3 May be bonded to at least one of the A ring or phi by a linking group or a single bond, respectively,
φ is a substituted or unsubstituted arylene or a substituted or unsubstituted heteroarylene, both having a bond between two adjacent ring-constituting atoms.
5. The polycyclic aromatic compound of claim 4, wherein L is > N-R L2 。
6. The polycyclic aromatic compound of claim 4, wherein L is 1,2-phenylene.
7. The polycyclic aromatic compound of any one of claims 1 to 6, wherein X is > N-,
z is > N-R Z2 O, or S.
8. The polycyclic aromatic compound of any one of claims 1 to 7, wherein Y is B.
9. The polycyclic aromatic compound according to claim 1, which is represented by any one of the following formulae,
Figure FDA0003858194950000021
10. the polycyclic aromatic compound according to claim 1, represented by the following formula,
Figure FDA0003858194950000022
11. a material for organic devices, comprising the polycyclic aromatic compound according to any one of claims 1 to 10.
12. An organic electroluminescent element comprising: a pair of electrodes including an anode and a cathode; and an organic layer disposed between the pair of electrodes, the organic layer containing the polycyclic aromatic compound according to any one of claims 1 to 10.
13. The organic electroluminescent element according to claim 12, wherein the organic layer is a light-emitting layer.
14. The organic electroluminescent element according to claim 13, wherein the light-emitting layer contains the polycyclic aromatic compound as a host material, and a dopant material.
15. The organic electroluminescent element according to claim 12, wherein the organic layer is an electron transport layer.
16. The organic electroluminescent element according to claim 12, wherein the organic layer is a hole transport layer.
17. A display device comprising the organic electroluminescent element according to any one of claims 12 to 16.
18. A lighting device comprising the organic electroluminescent element as claimed in any one of claims 12 to 16.
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