JP2021006523A - Spiroacridan-based compound, hole transport material comprising compound, and organic electronic device comprising compound in hole transport layer - Google Patents

Abstract

To provide a compound usable as a hole transport material excellent in hole injection and transport performance, electron blocking performance, optical stability, electrical stability, and thermal stability, to provide a hole transport material comprising the compound, and to provide an organic electronic device including an organic EL element or an organic photoelectric conversion element of which hole transport layer comprises the compound, in particular an organic electronic device including an organic EL element with long life and high light emission efficiency.SOLUTION: Provided is a compound represented by general formulae (1-1) to (1-3). (n, L, R and Ar1 to Ar5 are as defined in the specification.)SELECTED DRAWING: Figure 1

Description

The present invention relates to the provision of a novel compound, the use of the compound as a hole transport material or a material for an organic electronic device, and the provision of an organic electronic device using the compound.

As an organic electronic device that mutually converts electrical energy and light energy, a device including an organic electroluminescence element (organic EL element) or an organic photoelectric conversion element is known.

Of these, the organic EL element has a structure in which a light emitting material that emits light by an electric field is sandwiched between a cathode and an anode. The organic EL element is an element that causes a light emitting material to emit light by recombining holes and electrons injected from an electrode in a light emitting layer.

The organic EL element is a self-luminous type, has a wide viewing angle, and has excellent visibility. Therefore, the organic EL element is used as a display element for a display or the like. Further, the organic EL element is a thin solid element, which can be reduced in weight and has excellent strength. Therefore, a display using an organic EL element is useful not only for stationary types such as televisions but also for mobile applications. Further, the display element using the organic EL element can be easily changed in size and emits light on the entire surface, and is therefore useful for lighting applications.

Issues of the organic EL device include improvement of luminous efficiency (external quantum efficiency) and extension of life. Various devices have been devised to solve the above problems.
For example, an organic EL element is often provided with a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer in addition to the electrode and the light emitting layer. Usually, these layers are laminated in the order of anode, hole injection layer, hole transport layer, light emitting layer, electron transport layer, electron injection layer, and cathode. By providing these layers in addition to the electrodes and the light emitting layer, the probability that holes and electrons are recombined in the light emitting layer can be increased, and the luminous efficiency of the organic EL element can be improved.

The light emitting layer of an organic EL device is generally formed by doping a charge-transporting compound called a host material with a fluorescent compound or a phosphorescent compound called a guest material. The holes and electrons injected from the electrodes are recombined in the light emitting layer formed by the host material and the guest material, the energy of the excited host material is transferred to the guest material, and the guest material is excited by the energy. Efficient light emission can be obtained by being emitted as light energy.

In order to improve the recombination probability of holes and electrons, it is important to efficiently transfer both charges to the light emitting layer, so it is necessary to adjust the transport balance of holes and electrons.
To adjust the transport balance between holes and electrons, the hole mobility of hole injection materials and hole transport materials, the electron mobility of electron injection materials and electron transport materials, the charge injection barrier at the layer interface, and The balance must be adjusted after considering many factors such as the thickness of each film.
However, the transportability of holes and electrons of the material itself differs depending on the material, and a charge injection barrier occurs at the interface between layers formed of different materials, so holes and electrons are recombined in a well-balanced manner in the light emitting layer. It's not easy to get it done. An example of an imbalance between charge injection and transport is when either holes or electrons are few, or either is extremely large and passes through without recombination. When the charge flows out to the opposite electrode, there is also a method of providing a layer that blocks the charge and confining the charge in the light emitting layer to improve the recombination efficiency. Furthermore, high luminous efficiency can be obtained by the effect of confining the excitation energy generated in the light emitting layer. Normally, the hole transport layer and the electron transport layer often play the role of confining the outflowing charge and excitation energy in the light emitting layer, so the role played by the hole transport material is very important.

The properties required for hole transport materials used to increase the recombination efficiency of organic EL devices are high hole transport and low electron transport, as well as bandgap, ionization potential (IP), and electron affinity. It is important that the value of (Ea) has an appropriate value. The ionization potential of the hole transport material should be a value between the work function of the anode or the ionization potential of the hole injection material and the ionization potential of the light emitting material, thereby reducing the hole injection barrier to the light emitting layer. it can. It is desirable that the electron affinity of the hole transporting material is larger than the electron affinity of the light emitting material, whereby the electron blocking effect can be obtained. The HOMO level is used, which is almost synonymous with the ionization potential (IP), which is one of the indexes of the charge injection characteristics, and the LUMO level is used, which is almost synonymous with the electron affinity (Ea).

Regarding the life of the organic EL element, the optical stability and the electrical stability of the material are important (see, for example, Non-Patent Document 1 and Non-Patent Document 2). In a material having low photostability, the material deteriorates due to the excitation energy in the light emitting layer. Further, when the excitation energy of the hole transport layer is smaller than the excitation energy of the light emitting layer, the excitation energy generated in the light emitting layer moves to the hole transport layer, promotes deterioration of the hole transport material, and reduces the efficiency of the device. It is desirable that the excitation energy of the hole transport layer is higher than the excitation energy of the light emitting layer because it leads to conversion. On the other hand, in a material having low electrical stability, the material is deteriorated by holes and electrons flowing through the element, which causes low efficiency and short life.

Heat resistance and amorphousness are also important for extending the life of the device. In a material having low heat resistance, thermal decomposition occurs due to the heat generated when the element is driven, and the material deteriorates. A material with low amorphousness tends to crystallize, which accelerates the deterioration of the device. Therefore, the material used for the device is required to have high heat resistance and good amorphous property.
The glass transition temperature (Tg) is used as a measure of amorphousness, and when the Tg of the material is low, it crystallizes over a long period of time even under room temperature conditions and changes to a non-uniform film. It is said that the higher the Tg, the better. Considering the usage environment of the device, Tg is preferably at least 135 ° C. or higher.

Similar problems can occur in organic photoelectric conversion elements.

For example, Patent Document 1 reports a compound (P) represented by the following formula as a hole transport material used for a hole transport layer. The compound (P) has a different methylene group substituent in the acridane skeleton of the corresponding compound of the present invention, and has a phenyl group as the substituent, so that the electrical stability and the thermal stability are lowered. Can be considered. On the other hand, it is impossible to obtain a compound containing the spiroacridane skeleton of the present invention by the synthetic method described in Patent Document 1, and no clue for predicting the excellent effect of the compound is found.

Further, Patent Document 2 reports a compound (Q) represented by the following formula as a hole transport material used for a hole transport layer. The compound (Q) has a different methylene group substituent in the acridane skeleton of the corresponding compound of the present invention, and has a methyl group as the substituent, so that the electrical stability and the thermal stability are lowered. Can be considered. On the other hand, it is impossible to obtain a compound containing the spiroacridane skeleton of the present invention by the synthetic method described in Patent Document 2, and no clue for predicting the excellent effect of the compound is found.

Further, Patent Document 3 reports a compound (R) represented by the following formula as a hole transport material used for the hole transport layer. It is impossible to obtain a compound containing the spiroacridane skeleton of the present invention by the synthetic method described in Patent Document 3, and no clue for predicting the excellent effect of the compound is found.

Further, Patent Document 4 reports a compound (S) represented by the following formula as a material having a spiroacridane skeleton of the present invention. Since the compound (S) is used in the light emitting layer as a delayed fluorescent material, its use is different from that of the compound containing the spiroacrydan skeleton of the present invention.

Patent No. 6279647 Patent No. 6193215 European Patent No. 1840120 International Publication No. 2018/207750

Adv. Mater. , 24, 3212 (2012) Adv. Mater. , 22, 2468 (2010)

An object of the present invention is to provide a compound that can be used as a hole transport material having excellent hole injection or transport performance, electron blocking performance, photostability, electrical stability and thermal stability.
The present invention also provides a hole transport material containing the above compound, and an organic EL element or an organic electronic device including an organic photoelectric conversion element having a hole transport layer containing the above compound, particularly. An object of the present invention is to provide an organic electronic device including an organic EL element having a long life and high light emission efficiency.

As a result of various studies, the inventors have succeeded in synthesizing a novel compound represented by the following general formulas (1-1) to (1-3), and further, the compound is contained in an organic electronic device. The present invention has been completed by finding that it is extremely useful as a hole transport material for an EL element or an organic photoelectric conversion element, and in particular, it is possible to achieve high efficiency, long life, and low voltage drive of the organic EL element. ..

By using the compounds represented by the following general formulas (1-1) to (1-3) as the hole transport layer material, the inventors can obtain an organic EL element or an organic photoelectric conversion element contained in an organic electronic device. The reasons for higher efficiency and longer life are estimated as shown below.
That is, the compounds represented by the following general formulas (1-1) to (1-3) have a bulky and rigid structure due to the inclusion of the spiroacridane skeleton defined in the general formula, and the molecules of the compounds have a bulky structure. Stacking is suppressed. As a result, it is presumed that the compound exhibits high excitation energy, so that energy transfer from the light emitting layer is suppressed, and the device becomes highly efficient. In addition, by increasing the rigidity of the compound, electrical stability, optical stability and thermal stability are increased, which also contributes to extending the life of the organic EL element or organic photoelectric conversion element contained in the organic electronic device. It is estimated to be.

The gist of the present invention is as follows.
[1] General formula (1-1)

During the ceremony
n is 0 or 1;
L represents a divalent aromatic heterocyclic group formed from a single bond, a phenylene group, a naphthylene group, or any of a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or a triazine ring. The phenylene group, the naphthylene group, or the divalent aromatic heterocyclic group may further have a substituent;
Ar ^{1 to} Ar ⁵ each have an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a substituent independently of each other. It is a fused polycyclic aromatic group that may be present.
The compound represented by the above, except for the following compound (T).

[2] General formula (1-2) or (1-3)

During the ceremony
n is 0 or 1;
L represents a divalent aromatic heterocyclic group formed from a single bond, a phenylene group, a naphthylene group, or any of a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or a triazine ring. The phenylene group, the naphthylene group, or the divalent aromatic heterocyclic group may further have a substituent;
Ar ^{1 to} Ar ⁵ each have an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a substituent independently of each other. It is a fused polycyclic aromatic group that may be;
R is a linear, branched or cyclic alkyl group which may have a hydrogen, a heavy hydrogen, a halogen group or a substituent, a linear or a branched chain which may have a substituent. It is an aromatic hydrocarbon group which may have a cyclic or cyclic alkoxy group or a substituent, and is an aromatic hydrocarbon group.
The compound represented by.

[3] The compound according to [1] or [2], wherein L is a single bond, a phenylene group, or a naphthylene group.
[4] The compound according to any one of [1] to [3], wherein Ar ⁴ and Ar ⁵ are independent of each other and are a phenylene group, a biphenylene group, or a naphthylene group.
[5] The compound according to any one of [2] to [4], wherein R is a hydrogen or phenyl group.
[6] A hole transport material containing the compound according to any one of [1] to [5].

[7] An organic electronic device including an organic electroluminescence device or an organic photoelectric conversion element having a hole transport layer between a cathode and an anode.
An organic electronic device, wherein the hole transport layer contains the compound according to any one of the above [1] to [5].

[8] The organic electronic device according to the above [7], which includes an organic electroluminescence element having a light emitting layer between a hole transport layer and a cathode.
[9] The light emitting layer contains a host material and a guest material made of the light emitting material.
The organic electronic device according to the above [8], wherein the host material is an electron transporting material or a charge transporting material having both hole transporting property and electron transporting property.

The compound of the present invention can be used as a hole-transporting material for obtaining a hole-transporting layer having excellent photostability, electrical stability and thermal stability.
In particular, in the organic EL element of the present invention, the organic electronic device including the organic EL element provided with the hole transport layer containing the compound of the present invention has a long life, high light emission efficiency, and can be driven at a low voltage.

FIG. 1 is a schematic cross-sectional view for explaining an example of an organic EL element included in the organic electronic device of the present invention.

Hereinafter, the present invention will be described in more detail.
The present invention has the general formula (1-1).

During the ceremony
n is 0 or 1;
L represents a divalent aromatic heterocyclic group formed from a single bond, a phenylene group, a naphthylene group, or any of a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or a triazine ring. The phenylene group, the naphthylene group, or the divalent aromatic heterocyclic group may further have a substituent;
Ar ^{1 to} Ar ⁵ each have an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a substituent independently of each other. It is a fused polycyclic aromatic group that may be present.
With respect to the compound represented by.
However, the following compound (T) is excluded from the compound represented by the general formula (1-1).

The present invention also has the general formula (1-2) or (1-3).

During the ceremony
n is 0 or 1;
L represents a divalent aromatic heterocyclic group formed from a single bond, a phenylene group, a naphthylene group, or any of a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or a triazine ring. The phenylene group, the naphthylene group, or the divalent aromatic heterocyclic group may further have a substituent;
Ar ^{1 to} Ar ⁵ have an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a substituent, respectively, independently of each other. It is a condensed polycyclic aromatic group that may be;
R is a linear, branched or cyclic alkyl group which may have a hydrogen, a heavy hydrogen, a halogen group or a substituent, or a linear or a fraction which may have a substituent. It is an aromatic hydrocarbon group which may have a branched or cyclic alkoxy group or a substituent.
With respect to the compound represented by.

L in the general formulas (1-1) to (1-3) is more preferably a single bond, a phenylene group, or a naphthylene group.
N in the general formulas (1-1) to (1-3) is 0 or 1, and the electrical stability and thermal stability of the compounds represented by the general formulas (1-1) to (1-3) are sufficient. It is preferably 1 when the stability, the film-forming property, the ease of synthesis and purification, and the like are comprehensively judged.

As the aromatic hydrocarbon group, aromatic heterocyclic group and condensed polycyclic aromatic group in Ar ^{1 to} Ar ³ in the general formulas (1-1) to (1-3), or the aromatic hydrocarbon group in R. , For example, phenyl group, biphenyl group, terphenyl group, naphthyl group, anthracenyl group, phenanthrenyl group, fluorenyl group, indenyl group, pyrenyl group, perylenyl group, fluoranthenyl group, triphenylenyl group, pyridyl group, pyrimidyl group, triazinyl group. , Frill group, pyrrolyl group, thienyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, quinoxalinyl group, benzoimidazolyl group, pyrazolyl group, dibenzofuranyl Included are groups, dibenzothienyl groups, naphthyldinyl groups, phenanthrolinyl groups, acridinyl groups, and carborinyl groups.
The aromatic hydrocarbon group, aromatic heterocyclic group and condensed polycyclic aromatic group in Ar ^{1 to} Ar ³ preferably have a total of 6 to 25 carbons and heteroatoms forming a ring, and 6 to 20. Those of 6 to 18 are more preferable.

Substituents R, which may be possessed by the aromatic hydrocarbon group, aromatic heterocyclic group and condensed polycyclic aromatic group in Ar ^{1 to} Ar ³ in the general formulas (1-1) to (1-3). Examples of the substituent which the aromatic hydrocarbon group in the above may have, or the substituent which L may have, include a heavy hydrogen atom; a cyano group; a nitro group; a halogen group; a methyl group and an ethyl group. , A linear or branched alkyl group such as propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group; alkyloxy group such as methyloxy group, ethyloxy group, propyloxy group; vinyl group, allyl Alkenyl groups such as groups; aryloxy groups such as phenyloxy groups and phenyltrioxy groups; arylalkyloxy groups such as benzyloxy groups; phenyl groups, biphenyl groups, terphenyl groups, naphthyl groups, anthracenyl groups, phenanthrenyl groups and fluorenyl groups. Aromatic hydrocarbon groups such as groups, indenyl groups, pyrenyl groups, perylenyl groups, fluoranthenyl groups, triphenylenyl groups or condensed polycyclic aromatic groups; pyridyl groups, pyrimidyl groups, triazinyl groups, furyl groups, pyrrolyl groups, thienyl groups , Kinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, quinoxalinyl group, benzoimidazolyl group, pyrazolyl group, dibenzofuranyl group, dibenzothienyl group, naphthyldinyl group, Aromatic heterocyclic groups such as phenanthrolinyl group, acridinyl group, and carborinyl group or fused polycyclic aromatic groups; arylvinyl groups such as styryl group and naphthylvinyl group; acyl groups such as acetyl group can be mentioned. ..
Two or more of the substituents may be present, and when two or more of the substituents are present, each of them may be different.

As the substituent which the aromatic hydrocarbon group, the aromatic heterocyclic group and the condensed polycyclic aromatic group in Ar ^{1 to} Ar ³ in the general formulas (1-1) to (1-3) may have. , Electrical stability, thermal stability, film forming property, ease of synthesis and purification, etc. are comprehensively judged, and among the above examples, a linear alkyl group having 1 to 10 carbon atoms, or , A phenyl group, a biphenyl group, a terphenyl group or a naphthyl group in which one or more linear alkyl groups having 1 to 5 carbon atoms may be substituted is preferable, and a methyl group, an ethyl group, a propyl group or a butyl group. Alternatively, a phenyl group or a biphenyl group in which one or more linear alkyl groups having 1 to 3 carbon atoms may be substituted is more preferable, and a methyl group or a phenyl group is most preferable.

Ar ³ in the general formulas (1-1) to (1-3) may be bonded to L at an arbitrary position and may have a substituent, such as a phenyl group, a biphenyl group, or a tar-phenyl group. A naphthyl group, a carbazolyl group, a dibenzofuranyl group and a dibenzothienyl group are preferable, and a naphthyl group, a carbazolyl group and a dibenzofuranyl group which may be bonded to L at an arbitrary position and may have a substituent are particularly preferable. ..

Examples of the aromatic hydrocarbon group, aromatic heterocyclic group and condensed polycyclic aromatic group in Ar ⁴ and Ar ⁵ in the general formulas (1-1) to (1-3) include a phenylene group and a biphenylene group. Examples thereof include a turphenylene group, a naphthylene group, a fluorenylene group, a triphenylenyl group, a benzofuranylene group, a benzothienylene group, a carbazolylen group, a dibenzofuranyl group, and a dibenzothienyl group.
The aromatic hydrocarbon group, aromatic heterocyclic group and condensed polycyclic aromatic group in Ar ⁴ and Ar ⁵ preferably have a total of 6 to 18 carbons and heteroatoms forming a ring, preferably 6 to 12. The one is more preferable.

The curve connecting Ar ⁴ and Ar ⁵ in the general formula (1-1) indicates a single bond that may be bonded at any position. When Ar ⁴ or Ar ⁵ is an aromatic hydrocarbon group, an aromatic heterocyclic group, or a condensed polycyclic aromatic group containing two or more rings, such a single bond causes the two or more ring aromatic hydrocarbons. The group, aromatic heterocyclic group, or fused polycyclic aromatic group may be bonded to the other of Ar ⁴ or Ar ⁵ and to any of the rings of two or more rings.
Further, in the general formulas (1-2) and (1-3), Ar ⁴ and Ar ⁵ are together with the spiro ring of the five-membered ring or the six-membered ring sharing the solid line through the bond represented by the solid line. Form a fused ring.

As the substituents that the aromatic hydrocarbon group, the aromatic heterocyclic group and the condensed polycyclic aromatic group in Ar ⁴ and Ar ⁵ in the general formulas (1-1) to (1-3) may have. For example, a heavy hydrogen atom; a cyano group; a nitro group; a halogen group; a linear or branched alkyl group such as a methyl group, an ethyl group, a propyl group or an isopropyl group; an alkyloxy such as a methyloxy group or an ethyloxy group. Group; Alkenyl group such as vinyl group, allyl group; May have substituent, aryloxy group such as phenyloxy group, phenyltrioxy group; May have substituent, benzyloxy group, etc. Arylalkyloxy group; may have a substituent, an aromatic hydrocarbon group such as a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a triphenylenyl group or a condensed polycyclic aromatic group; Aromatic heterocyclic groups such as benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, dibenzofuranyl group, dibenzothienyl group, naphthyldinyl group, and phenanthrolinyl group, which may have a group A ring aromatic group; an arylvinyl group such as a styryl group or a naphthylvinyl group which may have a substituent; an acyl group such as an acetyl group can be mentioned.
Two or more of the substituents may be present, and when two or more of the substituents are present, each of them may be different.

As the substituents that the aromatic hydrocarbon group, the aromatic heterocyclic group and the condensed polycyclic aromatic group in Ar ⁴ and Ar ⁵ in the general formulas (1-1) to (1-3) may have. , Electrical stability, thermal stability, film forming property, ease of synthesis and purification, etc. are comprehensively judged, and among the above examples, a linear alkyl group having 1 to 10 carbon atoms, or , A phenyl group, a biphenyl group, a terphenyl group or a naphthyl group in which one or more linear alkyl groups having 1 to 5 carbon atoms may be substituted is preferable, and a methyl group, an ethyl group, a propyl group or a butyl group. Alternatively, a phenyl group or a biphenyl group in which one or more linear alkyl groups having 1 to 3 carbon atoms may be substituted is more preferable, and a methyl group or a phenyl group is most preferable.

Examples of the linear alkyl group in R in the general formula (1-3) include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group and decyl. Examples thereof include a group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group and an octadecyl group.
Examples of the branched alkyl group in R in the general formula (1-3) include 1-methylethyl group, 1-methylpropyl group, 1-ethylpropyl group, 1-n-propylpropyl group, 1 -Methylbutyl group, 1-ethylbutyl group, 1-propylbutyl group, 1-n-butylbutyl group, 1-methylpentyl group, 1-ethylpentyl group, 1-n-propylpentyl group, 1-n-pentylpentyl group, 1-Methylhexyl group, 1-ethylhexyl group, 1-n-propylhexyl group, 1-n-butylhexyl group, 1-n-pentylhexyl group, 1-n-hexylhexyl group, 1-methylheptyl group, 1 Examples thereof include -ethylheptyl group, 1-n-propylheptyl group, 1-n-butylheptyl group and 1-n-pentylheptyl group.

Examples of the cyclic alkyl group in R in the general formula (1-3) include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group, or bicycloalkyl. Examples include polycyclic alkyl groups such as groups and tricycloalkyl groups.
The linear, branched or cyclic alkoxy group in R in the general formula (1-3) includes, for example, an oxygen atom at the 1-position of the above linear, branched or cyclic alkyl group. An alkoxy group in which is located can be mentioned.
The linear, branched or cyclic alkyl group or alkoxy group preferably has 1 to 25 carbon atoms and preferably 1 to 15 carbon atoms from the viewpoint of glass transition temperature, steric hindrance and the like. More preferably, the number of carbon atoms is 1 to 8.

As a substituent that the linear, branched or cyclic alkyl group in R in the general formula (1-3), or the linear, branched or cyclic alkoxy group may have. Examples include an alkoxy group and a halogen group.
Two or more of the substituents may be present, and when two or more of the substituents are present, each of them may be different.

R are independent of each other when the electrical stability, thermal stability, film forming property, and ease of synthesis and purification of the compound represented by the general formula (1-3) are comprehensively judged. Most preferably, it is a hydrogen or phenyl group.

The methylene moiety of the acridane skeleton of the general formulas (1-1) to (1-3) is replaced with two predetermined (hetero) aryl groups, and the (hetero) aryl group forms a ring by a single bond. By substituting the benzene ring of the acrydan skeleton with Ar ² , the compound has a bulky and rigid molecular structure, and stacking of molecules is suppressed. As a result, the compound exhibits high excitation energy, and energy transfer from the light emitting layer to the hole transport layer containing the compound is suppressed, so that it is presumed that the electronic device including the organic EL element becomes highly efficient.
Further, the methylene portion of the acridane skeleton of the general formulas (1-1) to (1-3) is replaced with two predetermined (hetero) aryl groups, and the (hetero) aryl group forms a ring by a single bond. In addition, by substituting the benzene ring of the acridane skeleton with Ar ² , the rigidity of the compound is increased, so that the electrical stability, photostability and thermal stability are increased, and the compound is used as a hole transport layer. It is presumed that it also contributes to extending the life of the organic EL element including the organic EL element or the organic electronic device including the organic photoelectric conversion element.
Further, the methylene portion of the acridane skeleton of the general formulas (1-1) to (1-3) is replaced with two predetermined (hetero) aryl groups, and the (hetero) aryl group forms a ring by a single bond. In addition, by substituting the benzene ring of the acridane skeleton with Ar ² , the attack of the nucleophilic compound and the electrophilic compound on the N atom is sterically suppressed, so that electrical stability, photostability and thermal stability It is presumed that the stability is increased and the life of the organic EL element containing the compound in the hole transport layer or the organic electronic device including the organic photoelectric conversion element is extended.
The high excitation energy represented by the compounds represented by the general formulas (1-1) to (1-3) is particularly advantageous for use in electronic devices including blue light emitting organic EL elements.

Specific examples of the compounds represented by the general formulas (1-1) to (1-3) are shown below, but the present invention is not particularly limited thereto.

Among the compounds shown as the above specific examples, the compounds represented by the following chemical formulas (A) are examples of particularly preferable compounds from the viewpoints of charge injection characteristics, charge transport characteristics, electrical stability, thermal stability, and the like. ) To (I).

Since the compounds represented by the general formulas (1-1) to (1-3) have the above-mentioned characteristics, they can be used as a material for an organic EL element or a material for an organic photoelectric conversion element contained in an organic electronic device. In particular, it can be suitably used for the hole transport layer of the organic EL element, preferably the hole transport layer of the blue light emitting organic EL element. In particular, the compound enables high efficiency and long life of the organic EL element contained in the organic electronic device.
The present invention also relates to a hole transport material containing a compound represented by the general formulas (1-1) to (1-3).

The purity of the compounds represented by the general formulas (1-1) to (1-3) can be measured by high performance liquid chromatography (HPLC). High performance liquid chromatography applies pressure to the mobile phase into which the sample is introduced, passes the solvent through the mobile phase at a high flow velocity, separates the sample (mixture) on a column, and detects the separated sample with a detector. This is a method for measuring the purity of a sample.

The molecular weight of the compounds represented by the general formulas (1-1) to (1-3) can be measured by mass spectrometry (MS). Mass spectrometry is performed by applying a high voltage to a sample introduced from the sample introduction unit in a vacuum to ionize the sample, separating the ions according to the mass-to-charge ratio, and detecting the ions with the detection unit. ..
The sample introduction section can be directly connected to gas chromatography (GC / MS), high performance liquid chromatography (LC / MS), and capillary electrophoresis (CE / MS), and measures the molecular weight as well as the purity. be able to. A direct injection method (DI / MS), in which the sample is directly ionized, may also be adopted.
Various ionization methods are adopted as the ion source. For example, the electron ionization method (EI), the high-speed atomic collision method (FAB), the electrospray ionization method (ESI), the dielectric bond plasma method (ICP), and the like can be mentioned.

Nuclear magnetic resonance spectra (NMR) can be used to identify the compounds represented by the general formulas (1-1) to (1-3). In NMR measurement, information on chemical shifts and couplings can be obtained from the bonding state of atoms and the like, so that a spectrum peculiar to the compound can be obtained and the compound can be identified. The measurement is performed by dissolving a small amount of sample in various deuterated solvents.
The thermal stability of the compounds represented by the general formulas (1-1) to (1-3) can be evaluated by differential scanning calorimetry (DSC). The DSC measurement is performed by detecting the difference in the amount of heat from the standard sample when the sample undergoes a thermal change such as a phase transition or melting. By DSC measurement, the melting point of the compound and the glass transition temperature can be known.

By measuring the ultraviolet-visible absorption spectrum (UV / VIS), fluorescence spectrum (PL), and phosphorescence spectrum of the compounds represented by the general formulas (1-1) to (1-3), the UV absorption spectrum peculiar to the compound can be obtained. Not only can the fluorescence wavelength and phosphorescence wavelength be known, but also information such as the band gap of the compound, the fluorescence quantum yield, and the triplet energy can be known.
The HOMO level and LUMO level of the compounds represented by the general formulas (1-1) to (1-3) can be measured by cyclic voltammetry (CV). Ionization potential (IP) is also used as an index similar to the HOMO level.
Further, a method of obtaining the optical band gap from the UV absorption wavelength and calculating the LUMO level (or Ea) from the HOMO level (or IP) is also used.

One aspect of the organic electronic device of the present invention includes a light emitting layer and a hole transport layer arranged on the anode side of the light emitting layer between the cathode and the anode, and the hole transport layer is generally used. It contains an organic EL element containing the compounds represented by the formulas (1-1) to (1-3), and preferably contains a blue light emitting organic EL element.
FIG. 1 is a schematic cross-sectional view for explaining an example of an organic EL element included in the organic electronic device of the present invention. The organic EL element 1 shown in FIG. 1 has a first electrode 9 (anode), a hole injection layer 8, a hole transport layer 7, a light emitting layer 6, an electron transport layer 5, and an electron injection on the substrate 2. The layer 4 and the second electrode 3 (cathode) have a laminated structure formed in this order.
The organic EL element included in the organic electronic device of the present invention may have a hole transport layer in which one layer or two or more layers are laminated. Similarly, other layers of the organic EL device of the present invention (for example, a light emitting layer and an electron transporting layer) may also have one layer or two or more layers laminated.

In the organic EL element 1 shown in FIG. 1, all of the laminated structures constituting the organic EL element formed on the substrate 2 are made of an organic compound.
The organic EL element 1 shown in FIG. 1 is a hybrid organic-inorganic electroluminescent element (HOILED element) in which a layer made of an inorganic compound is contained in a laminated structure constituting the organic EL element 1 formed on the substrate 2. ) May be. In this case, for example, in the organic EL element 1 shown in FIG. 1, an electron injection layer 4 made of an inorganic oxide and a hole injection layer 8 made of an inorganic oxide are provided as layers made of an inorganic compound. Can be assumed to be. Since the inorganic compound is more stable than the organic compound, the HOILED device is preferable because it has higher resistance to oxygen and water than the organic EL device that does not contain a layer made of the inorganic compound.

Further, in the organic EL element 1 shown in FIG. 1, the case where the electron injection layer 4 and the hole injection layer 8 are provided will be described as an example. For example, the electron injection layer 4 and / or the hole The injection layer 8 may not be present. Further, in the organic EL element 1 shown in FIG. 1, an electron injection layer made of an inorganic compound may be provided instead of the electron injection layer 4 made of an organic compound, or the hole injection layer 8 made of an organic compound may be provided instead. A hole injection layer made of an inorganic compound may be provided.

The organic EL element 1 shown in FIG. 1 may be a top emission type that extracts light to the side opposite to the substrate 2 side, or may be a bottom emission type that extracts light to the substrate 2 side.
Further, the organic EL element 1 shown in FIG. 1 has a forward structure in which a first electrode 9 functioning as an anode is arranged between the substrate 2 and the light emitting layer 6.

Examples of the material of the substrate 2 include resin materials such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethylmethacrylate, polycarbonate and polyarylate, and quartz glass and soda glass. Examples include glass materials, and one or more of these can be used.

When the organic EL element 1 is a bottom emission type, a transparent material is used as the material of the substrate 2.
When the organic EL element 1 is of the top emission type, not only a transparent material but also an opaque material can be used as the material of the substrate 2. Examples of the opaque substrate include a substrate made of a ceramic material such as alumina, a metal substrate such as stainless steel in which an oxide film (insulating film) is formed on the surface, and a substrate made of a resin material. ..

The first electrode 9 in the organic EL element 1 shown in FIG. 1 functions as an anode. Examples of the material of the first electrode 9 include ITO (indium oxide tin), IZO (indium zinc oxide), FTO (fluorinated tin oxide), In ₃ O ₃ , SnO ₂ , Sb-containing SnO ₂ , Al-containing ZnO, and the like. Oxides can be mentioned. Among these, it is preferable to use ITO, IZO, and FTO as the material of the first electrode 9.

The material used for the hole injection layer 8 is selected from the viewpoint of the relationship between the work function of the anode and the IP of the hole transport layer, the charge transport characteristics, and the like. For example, poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (abbreviation: PEDOT: PSS), phthalocyanine compound typified by copper phthalocyanine (abbreviation: CuPc), molybdenum oxide (MoO _x ), oxidation. Acceptable heterocycles such as vanadium (V ₂ O ₅ ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN) Compounds can be used. Various organic compounds and inorganic compounds can be selected regardless of whether they are small molecules or polymers, as long as they have appropriate IP and charge transport properties. In addition, two or more of these materials can be used in combination.

The hole transport layer 7 contains compounds represented by the general formulas (1-1) to (1-3). By having a 2-substituted fluorene skeleton defined in the above general formula, the compound has appropriate HOMO and LUMO levels, and is excellent in photostability, electrical stability and thermal stability. Therefore, the charge recombination efficiency in the light emitting layer can be increased, and an organic EL device having a higher luminous efficiency and a long life can be realized.

The compounds represented by the general formulas (1-1) to (1-3) can be used alone as a hole transporting material, but existing hole transporting materials are mixed with one or more. It can also be used. Existing hole transporting materials include, for example, N, N-dibiphenyl-N'-terphenyl-N'-phenylbenzidine (abbreviation: HT1), N, N'-diphenyl-N, N'-di (abbreviation: HT1). α-naphthyl) benzidine (abbreviation: NPD), N, N'-diphenyl-N, N'-di (m-tolyl) benzidine (abbreviation: TPD), 1,1-bis [4- [N, N-di] Aromatic amine compounds such as (p-tolyl) amino] phenyl] cyclohexane (abbreviation: TAPC) or 4,4', 4''-tri-9-carbazolyltriphenylamine (abbreviation: TCTA), 1, Carbazole derivatives such as 3-bis (carbazole-9-yl) benzene (abbreviation: mCP) can be used.

A fluorescent material or a phosphorescent material can be used for the light emitting layer 6. As the luminescent material, a luminescent material (guest material) may be contained in a host material that carries out charge transport and charge recombination.
As the host material, a material having both hole transporting property and electron transporting property can be used. Further, since the hole transporting material of the present invention is also excellent in electron blocking performance, an electron transporting material can be used as the host material.

As the host material, for example, a metal complex such as an aluminum complex or a berylium complex, an anthracene derivative, an oxadiazole derivative, a benzimidazole derivative, or a phenanthrene derivative can be used.

The luminescent material is not particularly limited, but as the fluorescent material, for example, quinacridone, coumarin, rubrene, perylene and its derivatives, benzopyrane derivatives, rhodamine derivatives, aminostyryl derivatives, pyrene derivatives, aromatic amine derivatives, and tetracene derivatives can be used. it can. Further, as the phosphorescent material, for example, a metal complex such as iridium or platinum can be used. A green light emitting material such as Ir (ppy) ₃ , a blue light emitting material such as FIrpic, and a red light emitting material such as (Btp) ₂ Ir (acac) are used.

Examples of the material used for the electron transport layer 5 include metal complexes of quinolinol derivatives such as Alq ₃ and BAlq, anthracene derivatives, pyridine derivatives, pyrimidine derivatives, benzoimidazole derivatives, quinoxaline derivatives, phenanthroline derivatives, triazine derivatives, and carbazole derivatives. , Triazole derivatives can be used.
An electron transport layer containing a suitable LUMO level material is provided between the light emitting layer and the cathode or electron injection layer to alleviate the electron injection barrier from the cathode or electron injection layer to the electron transport layer, and further, the electron transport layer. The barrier to electron injection into the light emitting layer can be relaxed. Further, when the material has an appropriate HOMO level, the holes that flow out to the counter electrode without recombination in the light emitting layer are blocked, the holes are confined in the light emitting layer, and the recombination efficiency in the light emitting layer is enhanced. be able to.

The material used for the electron injection layer 4 is selected from the viewpoint of the work function of the cathode and the LUMO level of the electron transport layer. When the electron transport layer is not provided, the LUMO level of the light emitting material or the host material described later is taken into consideration. The electron injection material may be an organic compound or an inorganic compound.
When the electron injection layer is made of an inorganic compound, for example, lithium fluoride, sodium fluoride, potassium fluoride, cesium fluoride, or cesium carbonate may be used in addition to alkali metal and alkaline earth metal. Can be done.

The cathode of the organic EL element plays a role of injecting electrons into the electron injection layer or the electron transport layer. As the cathode, a material that acts as a cathode, such as various metal materials having a relatively small work function and various alloys, is used. Examples thereof include aluminum, silver, magnesium, calcium, gold, indium tin oxide (ITO), indium zinc oxide (IZO), magnesium indium alloy (MgIn), and silver alloy.
When the bottom emission method is adopted, an opaque electrode made of metal can be used as the cathode. Further, the cathode can be used as a reflective electrode.
When the top emission method is adopted, a transparent electrode such as ITO or IZO can be used as the cathode. Here, since ITO has a large work function, electron injection becomes difficult, and in order to form an ITO film, a sputtering method or an ion beam vapor deposition method is used, but it is applied to an electron transport layer or the like during film formation. May cause damage. Therefore, in order to improve electron injection and reduce damage to the electron transport layer during film formation, a magnesium layer or a copper phthalocyanine layer can be provided between the electron transport layer and ITO.

The organic photoelectric conversion element included in the organic electronic device of the present invention can also be manufactured according to the above-mentioned organic EL element.

Hereinafter, the present invention will be described in more detail with reference to examples of the present invention, but this is a specific specific example of the present invention, and the present invention is not limited thereto.

[Compound synthesis]
Example 1
Compound (A) was synthesized by the synthetic route shown below.

Compound (a-1) was synthesized by the method shown below.
2-Bromotriphenylamine (5.31 g, 16.4 mmol) and tetrahydrofuran (328 mL) were placed in a 500 mL four-necked flask equipped with a stir bar and substituted with argon, stirred, and cooled to −78 ° C. N-Butyllithium (1.6 M hexane solution, 12.5 mL, 19.7 mmol) was added dropwise thereto. After stirring for 1 hour, fluorenone (4.43 g, 24.6 mmol) was added, and the mixture was further stirred for 1 hour. Distilled water (50 mL) was added in small portions to terminate the reaction. The contents were transferred to a separating funnel, ethyl acetate was added to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 3/1) to obtain the target compound (a-1) (yield 6.21 g, yield 89%).

Compound (a-2) was synthesized by the method shown below.
Compound (a-1) (6.21 g, 14.6 mmol), dichloromethane (292 mL), and trifluoromethanesulfonic acid (0.50 mL, 5.65 mmol) in a 500 mL one-necked flask equipped with a stir bar and substituted with argon. ) Was added, and the mixture was stirred at room temperature for 30 minutes. Then, a saturated aqueous sodium hydrogen carbonate solution (30 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was purified by washing with methanol to obtain the target compound (a-2) (yield 5.41 g, yield 91%).

Compound (a-3) was synthesized by the method shown below.
Compound (a-2) (2.00 g, 4.91 mmol) and dichloromethane (98 mL) were placed in a 300 mL Schlenck tube equipped with a stirrer and substituted with argon, and the mixture was stirred and bromine (0.78 mL, 15) was placed therein. .2 mmol) was added dropwise. The mixture was stirred at room temperature for 3 hours. Then, the reaction vessel was cooled to 0 ° C., and a saturated aqueous sodium thiosulfate solution (30 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was purified by washing with methanol to obtain the target compound (a-3) (yield 2.96 g, yield 94%).

Compound (A) was synthesized by the method shown below.
Compound (a-3) (2.96 g, 4.60 mmol), 1-naphthalene boronic acid (2.45 g, 14.2 mmol), potassium carbonate (2.) were placed in a 300 mL Schlenk tube equipped with a stir bar and substituted with argon. 54 g, 18.4 mmol), toluene (83 mL), water (9.2 mL), and tetrakistriphenylphosphine palladium (0) (212 mg, 0.184 mmol) were added, sealed, and then stirred at 100 ° C. for 2 hours. Then, the reaction vessel was allowed to cool to around room temperature. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 30/1) and then washed with hexane to obtain the desired compound (A) (yield 928 mg). , Yield 26%). MS: m / z = 785

Example 2
Compound (B) was synthesized by the synthetic route shown below.

Compound (B) was synthesized by the method shown below.
Compound (a-3) (3.21 g, 4.99 mmol), 2-naphthalene boronic acid (2.66 g, 15.5 mmol), potassium carbonate (2.) were placed in a 300 mL Schlenk tube equipped with a stir bar and substituted with argon. 76 g, 19.9 mmol), toluene (90 mL), water (10 mL), and tetrakistriphenylphosphine palladium (0) (231 mg, 0.199 mmol) were added, sealed, and then stirred at 100 ° C. for 3 hours. Then, the reaction vessel was allowed to cool to around room temperature. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 1/1) and then washed with ethyl acetate to obtain the desired compound (B) (yield). 1.42 g, yield 36%). MS: m / z = 785

Example 3
Compound (C) was synthesized by the synthetic route shown below.

Compound (C) was synthesized by the method shown below.
Compound (a-3) (2.92 g, 4.53 mmol), dibenzofuran-4-boronic acid (3.07 g, 14.5 mmol), potassium carbonate (2) in a 300 mL Schlenk tube equipped with a stir bar and substituted with argon. .50 g, 18.1 mmol), toluene (65 mL), water (26 mL), and tetrakistriphenylphosphine palladium (0) (209 mg, 0.181 mmol) were added, sealed, and then stirred at 100 ° C. for 2 hours. Then, the reaction vessel was allowed to cool to around room temperature. The contents were transferred to a liquid separation funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated and obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 3/1) and then washed with hexane to obtain the desired compound (C) (yield 900 mg). , Yield 22%). MS: m / z = 905

Example 4
Compound (D) was synthesized by the synthetic route shown below.

Compound (d-1) was synthesized by the method shown below.
In a 300 mL four-necked flask equipped with a stir bar and substituted with argon, 10H-spiro [acridine-9,9'-fluorene] (2.43 g, 7.34 mmol), N, N-dimethylformamide (147 mL), and 1,3-Dibromo-5,5-dimethylhydantoin (2.31 g, 8.08 mmol) was added, and the mixture was stirred at room temperature for 2 hours. Then, the reaction vessel was cooled to 0 ° C., and a saturated aqueous sodium thiosulfate solution (30 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel, toluene was added to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 3/1) to obtain the target compound (d-1) (yield 2.60 g, yield 72%).

Compound (d-2) was synthesized by the method shown below.
Compound (d-1) (1.17 g, 2.93 mmol), dibenzofuran-4-boronic acid (1.06 g, 5.02 mmol), potassium phosphate (1.06 g, 5.02 mmol) in a 50 mL Schlenk tube equipped with a stir bar and substituted with argon. Add 870 mg, 7.17 mmol), toluene (16 mL), water (4 mL), and dichlorobis [di-tert-butyl (4-dimethylaminophenyl) phosphine] palladium (II) (16.9 mg, 0.0239 mmol). After sealing, the mixture was stirred at 100 ° C. for 3 hours. Then, the reaction vessel was allowed to cool to around room temperature. The contents were transferred to a liquid separation funnel, dichloromethane was added to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was washed with hexane to obtain the desired compound (d-2) (yield 1.47 g, yield 92%).

Compound (D) was synthesized by the method shown below.
Compound (d-2) (1.46 g, 2.19 mmol), 2- (4-bromophenyl) naphthalene (682 mg, 2.41 mmol), bis (tri) in a 50 mL Schlenk tube equipped with a stir bar and substituted with argon. -Tert-Butylphosphine) Palladium (0) (11.2 mg, 0.0219 mmol), toluene (22 mL), and tert-butoxysodium (316 mg, 3.29 mmol) are added, sealed, and then stirred at 100 ° C. for 2 hours. did. Then, the reaction vessel was allowed to cool to around room temperature, and water (30 mL) was put therein. The contents were transferred to a liquid separation funnel, dichloromethane was added to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated and obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 2/1) and then washed with toluene to obtain the desired compound (D) (yield 1). .52 g, yield 80%). MS: m / z = 865

Example 5
Compound (E) was synthesized by the synthetic route shown below.

Compound (e-1) was synthesized by the method shown below.
Compound (d-1) (3.35 g, 6.84 mmol), 2-naphthalene boronic acid (2.59 g, 15.0 mmol), potassium carbonate (2.) were placed in a 100 mL Schlenk tube equipped with a stir bar and substituted with argon. 84 g, 20.5 mmol), toluene (31 mL), water (3.4 mL), and dichlorobis [di-tert-butyl (4-dimethylaminophenyl) phosphine] palladium (II) (14.5 mg, 0.0205 mmol). After putting in and sealing, the mixture was stirred at 100 ° C. for 3 hours. Then, the reaction vessel was allowed to cool to around room temperature, hexane (30 mL) was put therein, and the precipitate was collected by filtration. The obtained precipitate was washed with hexane to obtain the target compound (e-1) (yield 3.42 g, yield 86%).

Compound (E) was synthesized by the method shown below.
Compound (e-1) (1.80 g, 3.08 mmol), 2-bromo-9,9'-spirobi [9H-fluorene] (1.34 g,) in a 100 mL Schlenk tube equipped with a stir bar and substituted with argon. 3.39 mmol), bis (tri-tert-butylphosphine) palladium (0) (15.8 mg, 0.0308 mmol), toluene (32 mL), and tert-butoxysodium (445 mg, 3.73 mmol) were added and sealed. Later, it was stirred at 100 ° C. for 4 hours. Then, the reaction vessel was allowed to cool to around room temperature, and water (30 mL) was put therein. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated obtained mixture was purified by silica gel column chromatography (developing solvent: cyclohexane / toluene = 1/1), and then washed with ethyl acetate to obtain the desired compound (E) (yield). 1.29 g, yield 42%). MS: m / z = 897

Example 6
Compound (F) was synthesized by the synthetic route shown below.

Compound (F) was synthesized by the method shown below.
Compound (d-2) (1.65 g, 2.48 mmol), 9- (4-bromophenyl) carbazole (1.04 g, 3.23 mmol), bis in a 200 mL Schlenk tube equipped with a stir bar and substituted with argon. (Tri-tert-butylphosphine) Palladium (0) (50.8 mg, 0.0993 mmol), toluene (60 mL), and tert-butoxysodium (358 mg, 3.73 mmol) were added, sealed, and then 23 at 100 ° C. Stir for hours. Then, the reaction vessel was allowed to cool to around room temperature, and water (30 mL) was put therein. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 3/1) and then washed with hexane to obtain the target compound (F) (yield 862 mg). , Yield 38%). MS: m / z = 904

Example 7
Compound (G) was synthesized by the synthetic route shown below.

Compound (g-1) was synthesized by the method shown below.
2-Bromoaniline (5.00 g, 29.1 mmol), 1-chloro-4-iodobenzene (17.3 g, 72.7 mmol), bis (tri-) in a 200 mL Schlenk tube equipped with a stir bar and substituted with argon. tert-Butylphosphine) Palladium (0) (594 mg, 1.16 mmol), toluene (291 mL), and tert-butoxysodium (6.98 g, 72.7 mmol) were added, sealed, and then stirred at 100 ° C. for 15 hours. .. Then, the reaction vessel was allowed to cool to around room temperature, and water (30 mL) was put therein. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated and obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 25/1) to obtain the target compound (g-1) (yield 6.49 g, yield 57%). ).

Compound (g-2) was synthesized by the method shown below.
Compound (g-1) (9.11 g, 23.2 mmol) and tetrahydrofuran (232 mL) were placed in a 500 mL four-necked flask equipped with a stir bar and substituted with argon, stirred, and cooled to −78 ° C. N-Butyllithium (1.6 M hexane solution, 17.7 mL, 27.8 mmol) was added dropwise thereto. After stirring for 1 hour, fluorenone (6.27 g, 34.8 mmol) was added, and the mixture was further stirred for 1 hour. Then, distilled water (50 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel, ethyl acetate was added to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 3/1) to obtain the target compound (g-2) (yield 4.54 g, yield 40%).

Compound (g-3) was synthesized by the method shown below.
Compound (g-2) (4.64 g, 9.39 mmol), dichloromethane (188 mL), and trifluoromethanesulfonic acid (0.25 mL, 2.82 mmol) in a 500 mL one-necked flask equipped with a stir bar and substituted with argon. ) Was added, and the mixture was stirred at room temperature for 1 hour. Then, a saturated aqueous sodium hydrogen carbonate solution (30 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was washed with hexane to obtain the desired compound (g-3) (yield 2.68 g, yield 60%).

Compound (G) was synthesized by the method shown below.
Compound (g-3) (2.68 g, 5.61 mmol), dibenzofuran-4-boronic acid (4.17 g, 19.7 mmol), potassium phosphate (19.7 mmol) in a 300 mL Schlenk tube equipped with a stir bar and substituted with argon. 4.77 g, 22.5 mmol), dioxane (112 mL), and bis (di-tert-butyl (4-dimethylaminophenyl) phosphine) dichloropalladium (II) (159 mg, 0.225 mmol) were added, sealed, and then sealed. The mixture was stirred at 110 ° C. for 30 hours. Then, the reaction vessel was allowed to cool to around room temperature. The contents were transferred to a separating funnel, water was added to separate the organic phase from the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated and obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 1/1) and then washed with hexane to obtain the desired compound (G) (yield 1). .45 g, yield 35%). MS: m / z = 739

Example 8
Compound (H) was synthesized by the synthetic route shown below.

Compound (h-1) was synthesized by the method shown below.
2-Bromo-9-fluorenone (2.50 g, 9.65 mmol), phenylboronic acid (1.29 g, 10.6 mmol), potassium carbonate (2.67 g) in a 200 mL Schlenk tube equipped with a stir bar and substituted with argon. , 19.3 mmol), toluene (87 mL), water (9.7 mL), and tetrakistriphenylphosphine palladium (0) (223 mg, 0.193 mmol), sealed, and then stirred at 100 ° C. for 4 hours. Then, the reaction vessel was allowed to cool to around room temperature. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated obtained mixture was washed with hexane to obtain the target compound (h-1) (yield 2.33 g, yield 94%).

Compound (h-2) was synthesized by the method shown below.
2-Bromotriphenylamine (2.60 g, 8.02 mmol) and tetrahydrofuran (160 mL) were placed in a 500 mL four-necked flask equipped with a stir bar and substituted with argon, stirred, and cooled to −78 ° C. N-Butyllithium (1.6 M hexane solution, 6.13 mL, 9.62 mmol) was added dropwise thereto. After stirring for 1 hour, compound (h-1) (2.45 g, 9.62 mmol) was added, and the mixture was further stirred for 1 hour. Distilled water (50 mL) was added in small portions to terminate the reaction. The contents were transferred to a separating funnel, ethyl acetate was added to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 3/1) to obtain the target compound (h-2) (yield 3.63 g, yield 90%).

Compound (h-3) was synthesized by the method shown below.
Compound (h-2) (3.63 g, 7.24 mmol), dichloromethane (145 mL), and trifluoromethanesulfonic acid (0.25 mL, 2.82 mmol) are placed in a 300 mL one-necked flask equipped with a stir bar. , Stirred at room temperature for 30 minutes. Then, a saturated aqueous sodium hydrogen carbonate solution (30 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was washed with methanol to obtain the desired compound (h-3) (yield 3.22 g, yield 92%).

Compound (h-4) was synthesized by the method shown below.
Compound (h-3) (3.22 g, 6.66 mmol) and dichloromethane (133 mL) were placed in a 300 mL Schlenck tube equipped with a stirrer and substituted with argon, and the mixture was stirred and bromine (1.20 mL, 23) was placed therein. .3 mmol) was added dropwise. The mixture was stirred at room temperature for 2 hours. Then, the reaction vessel was cooled to 0 ° C., and a saturated aqueous solution of sodium thiosulfate (30 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was washed with methanol to obtain the target compound (h-4) (yield 5.01 g, yield 100%).

Compound (H) was synthesized by the method shown below.
Compound (h-4) (3.46 g, 4.80 mmol), 2-naphthalene boronic acid (2.64 g, 15.4 mmol), potassium carbonate (2.) in a 100 mL Schlenk tube equipped with a stir bar and substituted with argon. 65 g, 19.2 mmol), toluene (22 mL), water (2.4 mL), and bis (di-tert-butyl (4-dimethylaminophenyl) phosphine) dichloropalladium (II) (34.0 mg, 0.0480 mmol) Was put in and sealed, and then stirred at 100 ° C. for 3 hours. Then, the reaction vessel was allowed to cool to around room temperature. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated obtained mixture was purified by silica gel column chromatography (developing solvent: dichloromethane) and then washed with ethyl acetate to obtain the desired compound (H) (yield 734 mg, yield 18%). ). MS: m / z = 861

Example 9
Compound (I) was synthesized by the synthetic route shown below.

Compound (i-1) was synthesized by the method shown below.
2-Bromodiphenylamine (2.50 g, 10.1 mmol) and tert-butyl methyl ether (50 mL) were placed in a 500 mL four-necked flask equipped with a stirrer and substituted with argon, stirred, and cooled to 0 ° C. N-Butyllithium (1.6 M hexane solution, 13.0 mL, 20.2 mmol) was added dropwise thereto. After stirring for 1 hour, 11H-benzo [b] fluorene-11-one (4.64 g, 20.2 mmol) was added, and the mixture was further stirred for 1 hour. Then, distilled water (20 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel, ethyl acetate was added to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The resulting mixture was placed in a 200 mL one-necked flask equipped with a stir bar, dichloromethane (34 mL) and trifluoromethanesulfonic acid (0.267 mL, 3.02 mmol) were added and stirred at room temperature for 30 minutes. Then, a saturated aqueous sodium hydrogen carbonate solution (30 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 3/1) to obtain the target compound (i-1) (yield 3.78 g, yield 98%).

Compound (i-2) was synthesized by the method shown below.
Compound (i-1) (3.78 g, 9.91 mmol), N, N-dimethylformamide (99 mL), and 1,3-dibromo-5,5 in a 300 mL Schlenk tube equipped with a stir bar and substituted with argon. -Dimethylformamide (2.85 g, 9.91 mmol) was added and stirred at room temperature for 1 hour. Then, a 5% aqueous sodium sulfite solution (20 mL) was added little by little to stop the reaction. The contents were transferred to a separating funnel, toluene was added to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The obtained mixture was washed with hexane to obtain the desired compound (i-2) (yield 4.31 g, yield 81%).

Compound (i-3) was synthesized by the method shown below.
Compound (i-2) (2.30 g, 4.27 mmol), 2-naphthalenboronic acid (1.64 g, 9.38 mmol), potassium carbonate (1.) were placed in a 100 mL Schlenck tube equipped with a stirrer and substituted with argon. 77 g, 12.8 mmol), toluene (19 mL), water (2.1 mL), and bis (di-tert-butyl (4-dimethylaminophenyl) phosphine) dichloropalladium (II) (9.1 mg, 0.0128 mmol) Was put in and sealed, and then stirred at 100 ° C. for 3 hours. Then, the reaction vessel was allowed to cool to around room temperature. Distilled water (5 mL) and hexane (20 mL) were added thereto, and the precipitate was collected by filtration to obtain the target compound (i-3) (yield 2.35 g, yield 87%).

Compound (I) was synthesized by the method shown below.
Compound (i-3) (2.94 g, 4.65 mmol), 2- (4-bromophenyl) naphthalene (1.45 g, 5.11 mmol), bis in a 150 mL Schlenk tube equipped with a stir bar and substituted with argon. (Tri-tert-butylphosphine) Palladium (0) (23.7 mg, 0.047 mmol), toluene (67 mL), and tert-butoxysodium (670 mg, 6.97 mmol) were added, sealed, and then 2 at 100 ° C. Stir for hours. Then, the reaction vessel was allowed to cool to around room temperature, and water (30 mL) was put therein. The contents were transferred to a separating funnel to separate the organic phase and the aqueous phase, the aqueous phase was removed, and the organic phase was further washed with water. The organic phase was dried over sodium sulfate. Then, sodium sulfate was removed by filtration, and the organic phase was concentrated. The concentrated obtained mixture was purified by silica gel column chromatography (developing solvent: cyclohexane / tetrahydrofuran = 1/1) and then washed with ethyl acetate to obtain the desired compound (I) (yield). 1.67 g, yield 35%). MS: m / z = 835

Example 10
Compound (A) synthesized in Example 1, compound (B) synthesized in Example 2, compound (C) synthesized in Example 3, compound (D) synthesized in Example 4, the above-mentioned Examples. Compound (E) synthesized in Example 5, compound (F) synthesized in Example 6, compound (G) synthesized in Example 7, compound (H) synthesized in Example 8, and Example 9 above. The DSC measurement of the compound (I) synthesized in 1 and the following comparative compounds (X) to (Z) was performed.

Table 1 shows Tg and decomposition temperature.

As shown in Table 1, it can be seen that the compound of the present invention is a material having a Tg of 135 ° C. or higher, a high decomposition temperature, and excellent thermal stability. The methylene moiety of the acridane skeleton of the general formulas (1-1) to (1-3) is replaced with two predetermined (hetero) aryl groups, and the (hetero) aryl group forms a ring by a single bond. It is considered that the substitution of the benzene ring of the acridan skeleton with Ar ² acted as one factor to bring about suitable thermal stability.

[Creation of organic EL element]
Example 11
A hole injection layer was formed by vacuum-depositing a compound HAT-CN having the following structural formula to a thickness of 10 nm on a glass substrate on which ITO (indium tin oxide) having a film thickness of 110 nm was formed. The compound HT1 having the following structural formula was vacuum-deposited on the hole injection layer to a thickness of 80 nm to form a first hole transport layer. Next, the produced compound (A) was vacuum-deposited on the first hole transport layer to a thickness of 10 nm to form a second hole transport layer. Next, the compound BD1 having the following structural formula was used as the guest material on the second hole transport layer, and the compound BH1 having the following structural formula was used as the host material, and the content of the guest material in the light emitting layer was set to 4% by weight. A light emitting layer having a thickness of 25 nm was formed. Next, the compound HB1 (25 nm) having the following structural formula and the compound ET1 (10 nm) having the following structural formula were sequentially vacuum-deposited on the light emitting layer to form an electron transport layer. Next, lithium fluoride (LiF) (1 nm) and aluminum (80 nm) were sequentially vacuum-deposited on the electron transport layer to form an electron injection layer and a cathode.

Example 12
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with compound (B).

Example 13
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with compound (C).

Example 14
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with compound (D).

Example 15
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with compound (E).

Example 16
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with compound (F).

Example 17
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with compound (H).

Example 18
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with compound (I).

Comparative Example 1
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with the comparative compound (X).

Comparative Example 2
An organic EL device was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with the comparative compound (Y).

Comparative Example 3
An organic EL element was formed in the same manner as in Example 11 except that the material of the second hole transport layer was replaced with the comparative compound (Z).

The voltage, external quantum efficiency, and chromaticity coordinates at a brightness of 1000 cd / m ² were measured for the obtained organic EL devices of Examples 11 to 19 and Comparative Examples 1 to 3. The element life was measured, and the results are shown in Table 2 below.
The element life was measured as the time until the emission brightness (initial brightness) of the element decreased to 50% in the constant current measurement of 100 mA / cm ² .

The organic EL elements of Examples 11 to 18 and Comparative Examples 1 to 3 all emitted blue light.
As shown in Table 2, the organic EL devices of Examples 11 to 18 having a hole transport layer containing the compound of the present invention can be driven at a low voltage, and have high external quantum efficiency and long-term device life. Indicated. The methylene moiety of the acridane skeleton of formulas (1-1) to (1-3) is replaced with two predetermined (hetero) aryl groups, and the (hetero) aryl group forms a ring by a single bond, and acridane. By substituting the benzene ring of the skeleton with Ar ² , the material has excellent thermal stability, and the attack of the nucleating compound and the electron-forming compound on the N atom is sterically suppressed, resulting in photostability and electricity. It is considered that the material has excellent thermal stability, and the organic EL element containing the compound in the hole transport layer can have a low voltage, a high efficiency, and a long life.
On the other hand, the organic EL devices of Comparative Examples 1 to 3 having a hole transport layer containing a comparative compound do not always have good drive voltage and external quantum efficiency, and further, the device life is extremely short, so that the display, lighting, etc. It was not possible to obtain sufficient properties for use in.

1 Organic EL element 2 Substrate 3 Second electrode (cathode)
4 Electron injection layer 5 Electron transport layer 6 Light emitting layer 7 Hole transport layer 8 Hole injection layer 9 First electrode (anode)

Claims (9)

General formula (1-1)
During the ceremony
n is 0 or 1;
L represents a divalent aromatic heterocyclic group formed from a single bond, a phenylene group, a naphthylene group, or any of a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or a triazine ring. The phenylene group, the naphthylene group, or the divalent aromatic heterocyclic group may further have a substituent;
Ar ^{1 to} Ar ⁵ each have an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a substituent independently of each other. The compound which is a condensed polycyclic aromatic group which may be present, except for the following compound (T).
General formula (1-2) or (1-3)
During the ceremony
n is 0 or 1;
L represents a divalent aromatic heterocyclic group formed from a single bond, a phenylene group, a naphthylene group, or any of a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or a triazine ring. The phenylene group, the naphthylene group, or the divalent aromatic heterocyclic group may further have a substituent;
Ar ^{1 to} Ar ⁵ have an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a substituent, respectively, independently of each other. It is a condensed polycyclic aromatic group that may be;
R is a linear, branched or cyclic alkyl group which may have a hydrogen, a heavy hydrogen, a halogen group or a substituent, a linear or a branched chain which may have a substituent. It is an aromatic hydrocarbon group which may have a cyclic or cyclic alkoxy group or a substituent, and is an aromatic hydrocarbon group.
The compound represented by. The compound according to claim 1 or 2, wherein L is a single bond, a phenylene group, or a naphthalene group. The compound according to any one of claims 1 to 3, wherein Ar ⁴ and Ar ⁵ are independent of each other and are a phenylene group, a biphenylene group, or a naphthylene group. The compound according to any one of claims 2 to 4, wherein R is a hydrogen or phenyl group. A hole transporting material containing the compound according to any one of claims 1 to 5. An organic electronic device including an organic electroluminescence device or an organic photoelectric conversion element having a hole transport layer between a cathode and an anode.
An organic electronic device, wherein the hole transport layer contains the compound according to any one of claims 1 to 5. The organic electronic device according to claim 7, further comprising an organic electroluminescence device having a light emitting layer between the hole transport layer and the cathode. The light emitting layer contains a host material and a guest material made of the light emitting material.
The organic electronic device according to claim 8, wherein the host material is an electron transporting material or a dual charge transporting material having hole transporting property and electron transporting property.