DE112013002910T5 - Connections for electronic devices - Google Patents

Abstract

The present invention relates to organic electroluminescent devices comprising compounds of the formula (1), in particular as blue singlet emitting materials in an electroluminescent layer

Description

The present invention describes novel compounds and their use in electronic devices.

• 1. Der Wirkungsgrad ist noch immer nicht hoch genug und sollte verbessert werden.
• 2. Es besteht noch immer Bedarf an einer Verbesserung der Betriebslebensdauer, insbesondere bei blauer (und auch grüner) Emission.
• 3. Die Betriebsspannung ist insbesondere bei Fluoreszenz-OLEDs hoch und sollte daher weiter abgesenkt werden, um die Energieausbeute zu verbessern.

The general structure of organic electroluminescent devices is z. Tie JP3564859B . US2008 / 0119671A1 . JP2007-224171A and KR20110002155A described. However, these devices still have significant problems that require urgent improvement:

• 1. The efficiency is still not high enough and should be improved.
• 2. There is still a need to improve operating life, especially with blue (and greener) emissions.
• 3. The operating voltage is high, especially in the case of fluorescent OLEDs, and should therefore be further lowered in order to improve the energy yield.

In particular, there is a strong demand for devices with a long life of the device and devices which exhibit consistently good efficiency and low operating voltage and have blue or green emitters. This is especially important for large-scale display applications. Here further improvements are desired, especially with blue emitting materials.

State of the art for emitter materials are pyrene derivatives which are substituted by two to four amino groups, according to KR2011002155A , However, no examples are disclosed of one or two electron-donating groups in combination with electron-withdrawing groups substituted in certain positions of the pyrene backbone.

The inventors of the present invention have surprisingly found that pyrene derivatives having one or two electron-withdrawing groups in ortho position to an electron-donating group have significant improvements here. In particular, these connections enable a long service life while maintaining a consistently high efficiency and low operating voltage compared to the corresponding conventional connections. The present invention therefore relates to these compounds and their use, in particular in OLEDs.

wo für die verwendeten Symbole und Indizes Folgendes gilt:
Y bedeutet eine elektronenabgebende Gruppe;
X bedeutet bei jedem Auftreten gleich oder verschieden F, Cl, -P(=O)(Ar)₂, -SO₂Ar, -SOAr oder CN;
dadurch gekennzeichnet, dass X sich in ortho-Position zum Y befinden muss;
Ar bedeutet bei jedem Auftreten gleich oder verschieden ein aromatisches oder heteroaromatisches Ringsystem mit 5 bis 40 aromatischen Ringatomen, das durch einen oder mehrere Reste R¹ substituiert sein kann, wobei zwei Ar durch E miteinander verbunden sein können;
E bedeutet bei jedem Auftreten gleich oder verschieden eine Einfachbindung, N(R¹), O, S, C(R¹)₂, C(R¹)₂-C(R¹)₂ oder Si(R¹)₂;
W bedeutet bei jedem Auftreten gleich oder verschieden CR¹ oder N, wenn W keinen Substituenten X oder Y aufweist; und W bedeutet C, wenn W einen Substituenten X oder Y aufweist;
R¹ bedeutet bei jedem Auftreten gleich oder verschieden H, D, F, Cl, Br, I, CN, NO₂, B(OR²)₂, Si(R²)₃, eine geradkettige Alkyl-, Alkoxy- oder Thioalkoxygruppe mit 1 bis 40 C-Atomen oder eine geradkettige Alkenyl- oder Alkinylgruppe mit 2 bis 40 C-Atomen oder eine verzweigte oder cyclische Alkyl-, Alkenyl-, Alkinyl-, Alkoxy- oder Thioalkoxygruppe mit 3 bis 40 C-Atomen, die jeweils durch einen oder mehrere Reste R² substituiert sein können, wo eine oder mehrere nicht benachbarte CH₂-Gruppen durch -R²C=CR²-, -C≡C-, Si(R²)₂, Ge(R²)₂, Sn(R²)₂, C=O, C=S, C=S, C=Se, C=NR², -O-, -S-, -COO- oder -CONR²- ersetzt sein können und wo ein oder mehrere H-Atome durch F, Cl, Br, I, CN oder NO₂ ersetzt sein können, oder ein aromatisches oder heteroaromatisches Ringsystem mit 5 bis 40 aromatischen Ringatomen, das durch einen oder mehrere nichtaromatische Reste R¹ substituiert sein kann, oder eine Aryloxy- oder Heteroaryloxygruppe mit 5 bis 40 aromatischen Ringatomen, die durch einen oder mehrere nichtaromatische Reste R¹ substituiert sein kann, oder eine Kombination dieser Systeme; zwei oder mehr Substituenten R¹ können hier auch ein mono- oder polycyclisches Ringsystem miteinander bilden;
R² bedeutet bei jedem Auftreten gleich oder verschieden H, D, F oder einen aliphatischen oder aromatischen Kohlenwasserstoffrest mit 1 bis 20 C-Atomen;
n steht bei jedem Auftreten gleich oder verschieden für 0 oder 1.The invention therefore relates to compounds of the formula (1)

where the following applies to the symbols and indexes used:
Y represents an electron-donating group;
X is the same or different at each occurrence and represents F, Cl, -P (= O) (Ar) ₂ , -SO ₂ Ar, -SOAr or CN;
characterized in that X must be orthogonal to the Y;
Ar means the same or different at each occurrence an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R ¹ , wherein two Ar may be linked together by E;
E is the same or different at each occurrence and is a single bond, N (R ¹ ), O, S, C (R ¹ ) ₂ , C (R ¹ ) ₂ -C (R ¹ ) ₂ or Si (R ¹ ) ₂ ;
W is the same or different CR ¹ or N at each occurrence, when W has no substituent X or Y; and W is C when W has a substituent X or Y;
R ¹ is the same or different at each occurrence as H, D, F, Cl, Br, I, CN, NO ₂ , B (OR ² ) ₂ , Si (R ² ) ₃ , a straight-chain alkyl, alkoxy or thioalkoxy group 1 to 40 carbon atoms or a straight-chain alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms, each represented by a or several radicals R ² can be substituted, where one or more non-adjacent CH ₂ groups by -R ² C = CR ² -, -C≡C-, Si (R ² ) ₂ , Ge (R ² ) ₂ , Sn (R ² ) ₂ , C = O, C = S, C = S, C = Se, C = NR ² , -O-, -S-, -COO- or -CONR ² - may be replaced and where one or several H atoms may be replaced by F, Cl, Br, I, CN or NO ₂ , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one or more non-aromatic radicals R ¹ , or an aryloxy or heteroaryloxy group having from 5 to 40 aromatic ring atoms en, which may be substituted by one or more non-aromatic radicals R ¹ , or a combination of these systems; two or more substituents R ¹ can here also form a mono- or polycyclic ring system with each other;
R ² each time identically or differently represents H, D, F or an aliphatic or aromatic hydrocarbon radical having 1 to 20 C atoms;
n stands for each occurrence the same or different for 0 or 1.

The group X, which identically or differently represents F, Cl, -P (OO) (Ar) ₂ , -SO ₂ Ar, -SOAr or CN at each occurrence, represents an electron-withdrawing group, ie a group which is a negative has mesomeric effect (-M effect).

An electron-donating group according to this invention is a monovalent group linked via an electron-rich heteroatom. In particular, an electron-donating group according to the invention is a group which has a positive mesomeric effect (+ M effect).

Electron-donating groups according to the invention are, for example, -N (Ar) ₂ , -P (Ar) ₂ , -OAr or -SAr. Preferably, an electron donating group is -N (Ar) ₂ or -P (Ar) ₂ .

For the purposes of the present invention, an aryl group or heteroaryl group is to be understood as meaning an aromatic or heteroaromatic group having a common aromatic electron system, where an aryl group contains 6 to 24 C atoms and a heteroaryl group contains 2 to 24 C atoms and a total of at least 5 contains aromatic ring atoms. The heteroatoms are preferably selected from N, O and / or S. For the purposes of this invention, it may be a single homo- or heterocyclic ring, for example, benzene, pyridine, thiophene, etc., or it may be a fused aromatic ring system in which at least two aromatic or heteroaromatic rings, e.g. B. benzene rings are fused, d. H. fused together by annulation, d. H. have at least one common edge and thus also a common aromatic system. This aryl or heteroaryl group may be substituted or unsubstituted; For example, existing substituents can form further ring systems. Thus, for example, systems such as naphthalene, anthracene, phenanthrene, pyrene, etc., are to be considered as aryl groups for purposes of this invention, and quinoline, acridine, dibenzothiophene, dibenzofuran, carbazole, etc. are to be considered heteroaryl groups for the purposes of this invention while, for example, biphenyl, Fluoren, spirobifluorene, etc. do not represent aryl groups, since there are separate aromatic electron systems.

For the purposes of this invention, an aromatic ring system contains 6 to 40 C atoms in the ring system. For the purposes of this invention, a heteroaromatic ring system contains from 2 to 40 carbon atoms and at least one heteroatom in the ring system, provided that the total number of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. For the purposes of this invention, an aromatic or heteroaromatic ring system is intended to mean a system which does not necessarily contain only aryl or heteroaryl groups, but in which additionally a plurality of aryl or heteroaryl groups are replaced by a short, non-aromatic moiety (less than 10% of the atoms, which are not H, preferably less than 5% of the atoms which are not H), e.g. B. a C, N or O atom can be interrupted. Thus, for example, systems such as 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ethers, etc. may also be considered as aromatic ring systems for purposes of this invention.

For the purposes of the present invention it is particularly preferred that a C ₁ to C ₄₀ alkyl group, a C ₂ to C ₄₀ alkenyl or a C ₂ to C ₄₀ alkynyl group, in the individual H atoms or CH ₂ groups can also be substituted by the abovementioned groups, the radicals methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n- Pentyl, s-pentyl, tert-pentyl, 2-pentyl, cyclopentyl, n-hexyl, s-hexyl, tert-hexyl, 2-hexyl, 3-hexyl, cyclohexyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1-methylcyclohexyl, n-octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo [2.2.2] octyl, 2-bicyclo [2.2.2] octyl, 2- (2,6 Dimethyl) octyl, 3- (3,7-dimethyl) octyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, heptynyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, Cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl or octynyl. A C ₁ - to C ₄₀ -alkoxy group is particularly preferably to be understood as meaning methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy or 2-methylbutoxy. Under a C ₂ -C ₂₄ -aryl or heteroaryl group, which may be monovalent or divalent depending on the use, in each case by the above Groups R ¹ may be substituted and may be linked to the aromatic or heteroaromatic ring system via any desired positions, are understood in particular groups which are derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene, benzanthracene, Tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzoin 6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazine imidazole, quinoxaline imidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1, 2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, pyrazine, phenazine, naphthyridine, azacarbazole, benzocarbo lin, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3, 4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4- Triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine, benzothiadiazole , For the purposes of this invention, aromatic and heteroaromatic ring systems are, in addition to the abovementioned aryl and heteroaryl groups, to be understood in particular to mean biphenyls, terphenyls, fluorene, spirobifluorene, dihydrophenanthrene, tetrahydropyrenes or cis- or trans-indenofluorene.

In a preferred embodiment of the invention, the group W is CH when W has no substituent Y or X; and W is C when W has a substituent Y or X.

wo die verwendeten Symbole und Indizes die vorstehend angegebenen Bedeutungen besitzen.Preferred embodiments of the invention are the compounds of one of the formulas (2) to (3),

where the symbols and indices used have the meanings given above.

Preference is given to compounds of the formulas (2) to (3) in which the symbol Y, identically or differently on each occurrence, represents -N (Ar) ₂ , -P (Ar) ₂ , -OAr or -SAr. The symbol Y more preferably represents -N (Ar) ₂ or -P (Ar) ₂ .

Preference is furthermore given to compounds of the formulas (2) to (3) in which the symbol n = 1.

Preference is furthermore given to compounds of the formulas (2) to (3) in which the symbol Ar is identical or different at each occurrence for an aromatic or heteroaromatic ring system having 5 to 16 aromatic ring atoms, for a triarylamine or for spirobifluorene, each being replaced by a or more radicals R ¹ may be substituted, in which case it is particularly preferred if the symbol Ar is an aryl or a heteroaryl group having 5 to 14 C atoms, which may be substituted by one or more radicals R ¹ .

It is particularly preferred if an aromatic or heteroaromatic ring system consists of benzene, ortho, meta or para biphenyl, fluorene, naphthalene, anthracene, phenanthrene, benzanthracene, pyridine, pyrene, thiophene, triphenylamine, diphenyl-1-naphthylamine, diphenyl 2-naphthylamine, phenyldi (1-naphthyl) amine and phenyldi (2-naphthyl) amine, each of which may be substituted by R ¹ . It is very particularly preferred if the symbol Ar, identical or different in each occurrence, represents phenyl, 1-naphthyl or 2-naphthyl, each of which may be substituted by one or two radicals R ¹ .

Preference is furthermore given to compounds of the formulas (1) to (3) in which the symbol R ^{1 is} identical or different at each occurrence for H, F, CN, a straight-chain alkyl group having 1 to 5 C atoms or a branched alkyl group having 3 to 5 C atoms, where in each case one or more non-adjacent CH ₂ groups can be replaced by -R ² C =CR ² -, -O- or -S- and where one or more H atoms can be replaced by F, or a monovalent aryl or heteroaryl group having 5 to 16 aromatic ring atoms which may be substituted by one or more non-aromatic radicals R ¹ , where two or more radicals R ^{1 may} together form a ring system.

R ¹ particularly preferably represents H, F, CN, methyl, tert-butyl or a monovalent aryl or heteroaryl group having 5 to 14 C atoms, which may be substituted by one or more non-aromatic radicals R ¹ , where two aromatic radicals R ¹ can form a ring system with each other.

Preferred structures of the formula (2) and (3) are the structures of the formulas (4) to (7) shown below.

The symbols and indices have the abovementioned meanings, where the compounds in all free positions can be substituted by groups R ¹ and are preferably unsubstituted.

Preference is given to compounds of the formulas (4) to (7) in which the symbol Y, identically or differently on each occurrence, represents -N (Ar) ₂ , -P (Ar) ₂ , -OAr or -SAr. Most preferably, the symbol Y represents -N (Ar) ₂ or -P (Ar) ₂ .

Preference is furthermore given to compounds of the formulas (1) to (7) in which the symbol X on each occurrence is identical or different from the group consisting of F, Cl, -P (OO) (Ar) ₂ , -SO ₂ Ar, -SOAr and CN is selected as electron withdrawing group. Particular preference is given to compounds of the formulas (1) to (7) in which the symbol X on each occurrence is identically or differently selected from F or CN, in particular CN.

The above statements indicate the preferred embodiments of the symbols and indices used. Particular preference is given to compounds of the formulas (1) to (7) in which the preferred embodiments indicated above are combined with one another.

Very preferred embodiments of the compounds according to the present invention are compounds according to one of the formulas (4) to (7), where
X is the same or different at each occurrence, F or CN;
YN (Ar) ₂ means;
Ar is the same or different at each occurrence, an aryl or a heteroaryl group having 5 to 14 carbon atoms, which may be substituted by one or more radicals R ¹ ; and
R ^{1 is} as defined above.

Examples of preferred compounds of the formulas (1) to (7) are the structures (1) to (50) shown below.

The compounds of the invention can be prepared by synthetic steps known in the art, such as bromination, Suzuki coupling, Hartwig-Buchwald coupling, etc. The compounds of formula (1) to formula (7) can be prepared as shown in Synthetic Schemes 1 and 2 ,

The 1,6- and 1,8-diaminopyrene derivatives (Scheme 1) can be synthesized according to the following reactions. The bromination of pyrene initially gives a mixture of two isomeric compounds (1,6- and 1,8-dibromopyrene). The isomers can be separated by recrystallization, for example. Subsequent Buchwald-Hartwig amination leads to diamino derivatives. The final products are obtained by subsequent bromination and cyanation of diamino derivatives.

The 2,7-diaminopyrene derivatives (Scheme 2) can be synthesized according to the following reactions. Pyren-2,7-bis (boronate) ester is obtained in a one-step synthesis using an iridium-based catalyst.

Syntheseschema 2:

The bromination of pyrene-2,7-bis (boronate) esters using a catalyst, for. As CuBr ₂ , provides 2,7-dibromopyrene. Subsequent Buchwald-Hartwig amination leads to diamino derivatives. The end products are obtained by subsequent bromination, optionally separation of the isomers and cyanation of diamino derivatives. Synthetic Scheme 1:

Synthesis Scheme 2:

Other compounds of this invention can be readily synthesized by these and similar synthetic schemes in procedures known to one skilled in the art of organic synthesis.

• a) Ausführen einer Bromierung eines Pyren-Derivats,
• b) gegebenenfalls Durchführen einer Auftrennung zur Isolierung des gewünschten Isomers;
• c) Ausführen einer Buchwald-Hartwig-Kupplungsreaktion mit einem Arylamin;
• d) Durchführen einer Bromierung und einer Cyanierung des Diaminopyren-Derivats.

The present invention therefore furthermore relates to a process for the preparation of a compound according to the invention which comprises

• a) carrying out a bromination of a pyrene derivative,
• b) optionally, carrying out a separation to isolate the desired isomer;
• c) performing a Buchwald-Hartwig coupling reaction with an arylamine;
• d) carrying out a bromination and a cyanation of the diaminopyrene derivative.

• a) Ausführen eines Borierungsschritts zu einem Pyren-2,7-bis(boronat)ester,
• b) Durchführen eines Bromierungsschritts, in dem Br in die Positionen des Bor eingeführt wird,
• c) Ausführen einer Buchwald-Hartwig-Kupplungsreaktion mit einem Arylamin,
• d) Durchführen einer Bromierung,
• e) gegebenenfalls Durchführen einer Auftrennung zum Abtrennen des gewünschten Isomers,
• f) Durchführen eines Cyanierungsschritts.

The present invention further relates to a process for the preparation of a compound of the invention which comprises

• a) carrying out a boration step to give a pyrene-2,7-bis (boronate) ester,
• b) carrying out a bromination step in which Br is introduced into the positions of boron,
• c) carrying out a Buchwald-Hartwig coupling reaction with an arylamine,
• d) carrying out a bromination,
• e) optionally carrying out a separation to separate off the desired isomer,
• f) performing a cyanation step.

The present invention also relates to the use of the compounds according to the invention in the corresponding devices and these devices as such.

The compounds of the formula (1) according to the invention are suitable for use in electronic devices, in particular in organic electroluminescent devices (OLEDs, PLEDs). The compounds are used in various functions and layers.

The invention further relates to organic electronic devices containing at least one compound of formula (1), in particular organic electroluminescent devices which comprise an anode, a cathode and at least one emitting layer, characterized in that at least one organic layer in which it is may be an emitting layer or another layer containing at least one compound of formula (1). Preferably, the layer containing the at least one compound according to formula (1) is an emitting layer.

In addition to the cathode, the anode and the emitting layer, the organic electroluminescent device may also contain further layers. These are, for example, each of one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, electron blocking layers, exciton blocking layers, charge generation layers (IDMC 2003, Taiwan, Session 21 OLED (5), T. Matsumoto, T. Nakada, J. Endo). K. Mori, N. Kawamura, A. Yokoi, J. Kido, Multiphoton Organic EL Device Having Charge Generation Layer) and / or organic or inorganic p / n junctions. It should be noted, however, that these layers need not necessarily be present in each case and the choice of layers always depends on the compounds used and in particular also on whether it is a fluorescent or phosphorescent electroluminescent device.

The organic electroluminescent device may also contain a plurality of emitting layers, wherein at least one organic layer contains at least one compound of the formula (1). These emission layers particularly preferably have a total of a plurality of emission maxima between 380 nm and 750 nm, which results in a white total emission, ie in the emitting layers different emitting compounds are used, which can fluoresce or phosphoresce and emit blue and yellow, orange or red light , Particularly preferred are three-layer systems, ie systems with three emitting layers, wherein at least one of these layers contains at least one compound of formula (1) and wherein the three layers show blue, green and orange or red emission (for basic structure see eg. WO 05/011013 ). Emitters that have broadband emission bands and thus exhibit white emission are also suitable for white emission.

The compounds of the formula (1) are particularly preferably used as emitter compounds, preferably in an emitting layer.

For the purposes of this invention, an emissive layer is a layer that can emit light. When the compounds of formula (1) are used as emitters, it may be preferable to use them in combination with one or more host materials. As the host material, it is preferable to use a material having a larger energy gap between HOMO level and LUMO level than the energy gap of the compounds of formula (1).

Preferred host materials are from the classes of oligoarylenes (e.g., 2,2 ', 7,7'-tetraphenylspirobifluorene according to U.S. Pat EP 676461 or dinaphthylanthracene), in particular the oligoarylenes containing condensed aromatic groups, the oligoarylenevinylenes (eg DPVBi or spiro-DPVBi according to US Pat EP 676461 ), the polypodal metal complexes (eg according to WO 04/081017 ), the hole-conducting compounds (eg according to WO 04/058911 ), the electron-conducting compounds, in particular ketones, phosphine oxides, sulfoxides, etc. (for example according to US Pat WO 05/084081 and WO 05/084082 ), the atropisomers (eg according to WO 06/048268 ), the boronic acid derivatives (eg according to WO 06/117052 ) or the benzanthracenes (eg according to WO 08/145239 ). Particularly preferred matrix materials are selected from the classes of the oligoarylenes comprising naphthalene, anthracene, benzanthracene and / or pyrene or atropisomers of these compounds, the oligoarylenevinylenes, the ketones, the phosphine oxides and the sulphoxides. Very particularly preferred matrix materials are selected from the classes of oligoarylenes, including anthracene, benzanthracene, benzophenanthrene and / or pyrene or atropisomers of these compounds, as described in US Pat WO 2008/145239 revealed anthracenes. For the purposes of this invention, an oligoarylene is to be understood as meaning a compound in which at least three aryl or arylene groups are bonded to one another.

If the compound of the formula (1) is used as an emitter in an emitting layer, then the proportion of the emitter of the formula (1) in the emitting layer is between 0.01% by volume and 100%, preferably between 0.1% by volume. % and 50% by volume. Particularly preferably, the proportion is between 0.5% by volume and 20% by volume, more preferably between 1% by volume and 10% by volume.

Further preferred is an organic electroluminescent device, characterized in that one or more layers have been applied by a sublimation process. The materials are vacuum deposited in vacuum sublimation units at an initial pressure of usually below 10 ^-5 mbar, preferably below 10 ^-6 mbar. However, the initial pressure may be even lower, e.g. B. below 10 ^-7 mbar.

Likewise preferred is an organic electroluminescent device, characterized in that one or more layers by the OVPD method (organic vapor phase deposition - organic vapor deposition) or by means of carrier gas sublimation are applied. Here, the materials are applied at a pressure between 10 ^-5 mbar and 1 bar. A special case of this process is the OVJP process (organic vapor jet printing), in which the materials are applied directly by means of a nozzle and structured therewith (for example, BMS Arnold et al., Appl. Phys. Lett., 2008, 92, 053301). ,

Further preferred is an organic electroluminescent device, characterized in that one or more layers are prepared from the solution, for example by spin coating, or by means of any printing process, such as. As screen printing, flexographic printing or offset printing, but particularly preferably LITI (Light Induced Thermal Imaging, thermal transfer printing) or ink jet printing. For this purpose, soluble compounds of formula (1) are required. High solubility can be achieved by suitable substitution of the compounds, for example with long-chain alkyl groups or oligophenyl groups such as quaterphenyl groups.

The processing of the compounds of the invention from the liquid phase, for. B. by spin coating or by printing processes, requires formulations of the compounds of the invention. These formulations may, for example, be dispersions or miniemulsions. It may be preferable to use mixtures of two or more solvents for this purpose. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, dimethylanisole, mesitylene, tetralin, veratrol, THF, methyl THF, THP, chlorobenzene, dioxane, phenoxytoluene, especially 3-phenoxytoluene, or Mixtures of these solvents.

The present invention therefore furthermore relates to a formulation, in particular a solution or dispersion which comprises at least one compound of the formula (1) or the preferred embodiments indicated above and at least one solvent, in particular an organic solvent. The manner in which solutions of this kind can be made is known to the person skilled in the art and, for example, in US Pat WO 2002/072714 . WO 2003/019694 . WO 2010/093592 and the literature cited therein.

Although the description is mainly concerned with the use in OLEDs, it is possible for a person skilled in the art without further inventive step, the compounds according to the invention also for other applications in other electronic devices, for example, organic field effect transistors (O-FETs). , organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic integrated circuits (O-ICs), organic solar cells (O -SCs), organic field-quench devices (O-FQDs), light-emitting electrochemical cells (LECs), organic photoreceptors, or organic laser diodes (O-lasers), to name but a few applications call to use.

• 1. Bei der Verwendung als Emitter in der Emissionsschicht zeigen die erfindungsgemäßen Verbindungen eine längere Betriebslebensdauer als Verbindungen des Standes der Technik.
• 2. Vorzugsweise sind Wirkungsgrad, Betriebsspannung und Farbkoordinaten entsprechender Vorrichtungen der erfindungsgemäßen Verbindungen ebenfalls besser als Vorrichtungen mit Verbindungen nach dem Stand der Technik.

The compounds according to the invention have the following surprising advantages over the prior art when used in organic electroluminescent devices:

• 1. When used as an emitter in the emission layer, the compounds of the invention exhibit a longer service life than prior art compounds.
• 2. Preferably, the efficiency, operating voltage and color coordinates of corresponding devices of the compounds according to the invention are also better than devices with compounds according to the prior art.

applications

The invention will be explained in more detail by the following examples, without being restricted thereto.

The following syntheses were carried out under a protective gas atmosphere, unless stated otherwise. The starting materials were purchased from ALDRICH or ABCR unless otherwise specified. The starting point can be, for example, 1,6-, 2,7- or 1,8-dibromopyrene, Journal of the American Chemical Society, 2004, 126 (14), 4540; Angew. Chem. Int. Ed. 2008, 47, 10175, Chemical Reviews DOI: 10.1021 / cr100428a, Chem. Comm. 2005, 2172, his.

The intermediates can be prepared as follows. (Intermediates 1 to 19) Intermediate 1: Synthesis of 1,6- and 1,8-dibromopyrene

In 1750 ml of chloroform 58 g (0.287 mol) of pyrene are presented. Then, a solution of 31 ml (0.609 mol) of Br ₂ in 250 ml of chloroform is added dropwise at RT under exclusion of light. The reaction mixture is heated at reflux for 4 h. After cooling, the precipitated solid is filtered off with suction and washed with ethanol and dried. The resulting solid is recrystallized 3 times from CHCl ₃ . Yield: 1,6-dibromopyrene 73.4 g (0.201 mol), 71.1% of theory, and 1,8-dibromopyrene 20.6 g (0.06 mol), 20% of theory.

Intermediate 2: Synthesis of 2,7-dibromopyrene

Intermediate 2-1: Synthesis of 2,2 '- (2,7-pyrenediyl) bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolane)

12.03 g (59.5 mmol) of pyrene, 33.5 g (131.8 mmol) of bis (pinacolato) diborane and [Ir (OMe) COD] ₂ (5 mol%) and 4,4'-di- tert-butyl-2,2'-bipyridine (10 mol%) are suspended in 750 ml of cyclohexane. The reaction mixture is heated at reflux for 16 h. After cooling, the organic phase is separated, washed three times with 200 ml of water and then evaporated to dryness. The residue is recrystallized from toluene. The product content is by ¹ H-NMR about 97% with a total yield of 21.43 g (80%). Intermediate 2-2: Synthesis of 2,7-dibromopyrene

45.4 g (0.1 mol) of 2,2 '- (2,7-pyrenediyl) bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolane) and 111.5 g (0, 5 mol) of copper (II) bromide are suspended in 750 ml of i-PrOH and 300 ml of water. The reaction mixture is heated at reflux for 16 h. After cooling, the solid is separated and washed three times with 200 ml of water. The residue is recrystallized from toluene. The product content is by ¹ H-NMR about 96% with a total yield of 29.52 g (82%).

Unless stated otherwise, the following syntheses are carried out in dried solvents under a protective gas atmosphere. The starting materials can be purchased from ALDRICH. Intermediate 3: Synthesis of N, N, N ', N'-tetrakis (2,4-dimethylphenyl) pyrene-1,6-diamine

19.08 g (0.053 mol) of 1,6-dibromopyrene and 27.0 g (0.12 mol) of N- (2,4-dimethylphenyl) -2,4-dimethylphenylamine (Miguel Angel Chem Taiwan) are dissolved in 500 ml of xylene solved and degassed. 0.15 ml (0.66 mmol / 1 M solution in toluene) of tri-tert-butylphosphine, 15.61 g (0.162 mol) NaOtBu and 89.44 mg (0.398 mmol) Pd (OAc) ₂ are added, and the mixture is again degassed and heated at reflux for 12 hours. After completion of the reaction, the warm mixture is filtered through alumina B (activity level 1), washed with water, dried and evaporated. The residue is purified by Soxhlet extraction with toluene / heptane (1: 1) and crystallized from toluene. The product content is by HPLC 98% with a total yield of 14.8 g (43%).

Zwischenprodukt 11: Synthese von 2,7-Dibrom-N,N,N',N'-tetrakis(2,4-dimethylphenyl)-pyren-1,6-diamin

The following compounds can be obtained analogously:

Intermediate 11: Synthesis of 2,7-dibromo-N, N, N ', N'-tetrakis (2,4-dimethylphenyl) -pyrene-1,6-diamine

In 1850 ml of DMF 80.7 g (0.1 mol) of N, N, N ', N'-tetrakis (2,4-dimethylphenyl) pyrene-1,6-diamine are introduced. Then added dropwise at -15 ° C under exclusion of light, a solution of 11 ml (0.2 mol) of Br ₂ in 100 ml of acetonitrile, the mixture is allowed to come to room temperature and stirred for a further 4 h at this temperature. The mixture is then mixed with 250 ml of water and then extracted with ethyl acetate. The organic phase is dried over MgSO ₄ and the solvent removed in vacuo. The product is washed by stirring with hot heptane and filtered with suction. Yield: 16.94 g (0.02 mol), 21% of theory, purity according to ¹ H-NMR about 97%.

Verbindung 1: Synthese von 2,7-Dicyano-N,N,N',N'-tetrakis-(2,4-dimethylphenyl)-pyren-1,6-diamin

The following compounds can be obtained analogously:

Compound 1: Synthesis of 2,7-dicyano-N, N, N ', N'-tetrakis- (2,4-dimethylphenyl) -pyrene-1,6-diamine

16.94 g (0.02 mol) of 2,7-dibromo-N, N, N ', N'-tetrakis- (2,4-dimethylphenyl) -pyrene-1,6-diamine are initially charged in dimethylformamide and treated with pyridine (5 ml) and 5.16 g (0.058 mol) of copper (I) cyanide were added. The reaction mixture is heated at 150 ° C for 20 h at reflux. 200 ml of 10% NH ₄ OH solution are added dropwise to the cooled mixture and then 500 ml of heptane and a further 100 ml of water are added. The precipitated solid is filtered off with suction through a frit and dried at 40 ° C in a vacuum. The resulting solid is recrystallized 5x from dioxane / toluene and sublimed in vacuo (10 ^-5 mbar, 340 ° C), yielding 5.2 g (37%) of 2,7-dicyano-N, N, N ', N'. Tetrakis (2,4-dimethylphenyl) pyrene-1,6-diamine gives as a colorless solid. Purity> 99.9%.

Verbindung 9: Synthese von N,N,N',N'-Tetrakis-(2,4-dimethylphenyl)-2,7-difluor-pyren-1,6-diamin

The following compounds can be obtained analogously:

Compound 9: Synthesis of N, N, N ', N'-tetrakis (2,4-dimethylphenyl) -2,7-difluoropyrene-1,6-diamine

25 mmol of 2,7-dibromo-N, N, N ', N'-tetrakis (2,4-dimethylphenyl) pyrene-1,6-diamine are dissolved in 600 ml of dry THF and the mixture is brought to -78 ° C cooled. In the course of about 30 minutes 26.2 ml (65.7 mmol / 2.5 M in hexane) of n-BuLi are added at this temperature and the mixture is then stirred at -78 ° C for a further 2.5 h. At this temperature, 7.3 ml (65.7 mmol) of trimethyl borate are added as quickly as possible, and the reaction is allowed to come to RT slowly (about 18 h). The reaction mixture is mixed with 2.64 g (66 mmol) of NaOH in 20 ml of MeOH and then cooled to 0 ° C and treated with AgOTf (1.05 eq.). After 1 hour at 0 ° C, the organic phase is azeotroped using acetone. 200 ml of acetone are added dropwise to the cooled mixture, and then MS3Å (5.0 g) and 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo [2.2.2] octane-bis (trifluoroborate) (23.72 g, 66 mmol, 1.05 equiv.). After 3 hours at room temperature, the reaction solution is filtered through Celite and washed with water, and the precipitated solid is filtered off with suction through a frit and dried at 40 ° C in a vacuum.

The resulting solid is recrystallized 5x from dioxane / toluene and sublimed in vacuo (10 ^-5 mbar, 360 ° C), yielding 5.2 g (37%) of N, N, N ', N'-tetrakis- (2, 4-dimethylphenyl) -2,7-difluoropyrene-1,6-diamine as a colorless solid. Purity> 99.9%.

The following compounds can be obtained analogously:

Device Examples (V1 to Esol): Preparation of vacuum deposited OLEDs

Vacuum-evaporated OLEDs and OLEDs according to the prior art according to the invention are prepared by a general method according to WO 2004/058911 which is adapted to the circumstances described here (variation of layer thickness, materials used).

The data for various OLEDs are shown in Examples V1 to Esol below (see Table 2). For better processing, glass plates coated with structured ITO (Indium-Tin-Oxide) in a thickness of 50 nm are used with 20 nm PEDOT (poly (3,4-ethylenedioxy-2,5-thiophene), spun from water, purchased from Heraeus Precious Metals GmbH & Co. KG, Germany These coated glass plates form the substrates to which the OLEDs are applied.The OLEDs have, in principle, the following layer structure: Substrate / optional hole-injection layer (HIL) / hole transport layer (hole transport layer - HTL) / optional interlayer (IL) / electron-blocking layer (EBL) / emission layer (EML) / hole-blocking layer (HBL) / electron transport layer (electron transport layer) layer - ETL) / optional electron injection layer (EIL) and finally a cathode The cathode is passed through a 100 nm thick aluminum Sc The exact structure of the OLEDs is shown in Table 1. The materials required for the preparation of the OLEDs are shown in Table 3.

The materials are deposited by thermal vapor deposition in a vacuum chamber. In this case, the emission layer always consists of at least one matrix material (host material) and an emitting dopant (emitter), which is admixed to the matrix material or the matrix materials in a specific volume fraction by co-evaporation. An expression like H1 (95%): SEBV1 (5%) here means that the material SEBV1 is present in the layer in a volume fraction of 5%, H1 in a volume fraction of 95%. Similarly, the electron transport layer may also consist of a mixture of two materials.

The materials of the present invention can also be applied from solution and result in good device performance OLEDs that have a simpler device structure compared to vacuum processed devices, see Examples Esol vs Vsol.

The production of these devices proceeds in accordance with the production of polymer light emitting devices (PLEDs), which is described in various ways in the literature (for example in US Pat WO 2004/037887 A2 ). The configuration consists of substrate / ITO / PEDOT (80 nm) / interlayer / emission layer (50 nm) / ETL / cathode. The hole injection takes place via the intermediate layer; in this case, HIL-012 (HILsol) from Merck was used. In this application, the dopant of the invention to be used in the emission layer is dissolved in toluene together with the matrix. An expression such as Hsol (92%): SEBV1 (8%) here means that the material SEBV1 is present in the layer in a proportion by weight of 8% and Hsol in a proportion by weight of 92%. The typical concentration of these solutions is in the range between 16 and 25 g / L, if, as in this case, a layer thickness of 50 nm by spin-coating is required. The emission layer is spin-coated in an inert atmosphere, in this case argon, and dried at a temperature of 120 ° C. for 10 minutes. Between EML and cathode, the aforementioned layers HBL and ETL can be evaporated on the EML; the intermediate layer may equally be replaced by one or more layers, provided that the processing of the subsequent layers, such as the EML, does not dissolve the solution from the solution previously applied.

The OLEDs are characterized according to standard methods. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd / A), the energy yield (measured in Im / W) and the external quantum efficiency (EQE, measured in percent) as a function of the luminance, are calculated from electricity Voltage Luminance Characteristics (IUL characteristics), and the lifespan is determined. The electroluminescence spectra are measured at a brightness of 1000 cd / m ² and used to calculate the x and y color coordinates according to CIE 1931. The lifetime is defined as the time after which the light density has dropped from a certain initial light density to a certain level. The term LD70 @ 50 mA means that the stated lifetime is the time at which the light density has dropped to 70% of the initial light density when operating the device at a constant current of 50 mA / cm ² , see table. The values for the lifetime can be taken into account by means of conversion formulas known to those skilled in the art into a number for other initial light densities.

The data for the different OLEDs (Examples V1 to Esol) are summarized in Table 2. Examples V1 and Vsol are comparative examples of the prior art, examples E1-Esol show data for OLEDs in which materials according to the invention are used.

Some of the examples are explained in more detail below in order to demonstrate the advantages of the compounds according to the invention. It should be noted, however, that this is only a selection of the results shown in Table 2. As can be seen from the table, substantial improvements over the prior art are achieved even when using the compounds according to the invention, which are not described in detail. In some cases, improvement is achieved in all parameters, in some cases, however, only one improvement in one parameter, e.g. B. in the yield or voltage or life. However, the improvement of one of the mentioned parameters represents a significant advance.

Use of compounds according to the invention as emitters in fluorescent OLEDs

The use of compounds according to the invention as emitters (dopants) in OLEDs thus provides significant improvements in terms of their lifetime, in particular together with a deep blue color.

Examples are shown with green and blue emitting OLEDs using compounds of the invention. Compared with the comparison compound SEBV1 from the KR2011-0002155 shows SEBV1 compared to compounds according to this invention with similar CIE coordinates, e.g. B. V1 compared with E3, a shorter life.

The emitters of this invention exhibit a narrow emission spectrum, are effective, and exhibit long life. In addition, they can be used in low doping concentration.

In addition, many of the devices according to the invention show deeper blue color coordinates with a similar lifetime compared to the comparative example V1 (E1, E2, E4, E5).

Examples E6 and E7 according to the invention show green emission with a long service life (180 h and 220 h).

When processed from solution, the emitter according to the invention shows a good lifetime in combination with deep blue color (Esol). Table 1: Structures of the OLEDs Example IL HTL EBL EML ETL thickness thickness thickness thickness thickness V1 HIL1 5 nm HTM1 140 nm NPB 20 nm H1 (95%): SEBV1 (3%) 20 nm ETM1 (50%): LiQ (50%) 30 nm E1 HIL1 5 nm HTM1 140 nm NPB 20 nm H1 (95%): SEB1 (3%) 20 nm ETM1 (50%): LiQ (50%) 30 nm E2 HIL1 5 nm HTM1 140 nm NPB 20 nm H1 (95%): SEB2 (3%) 20 nm ETM1 (50%): LiQ (50%) 30 nm E3 HIL1 5 nm HTM1 140 nm NPB 20 nm H1 (95%): SEB3 (3%) 20 nm ETM1 (50%): LiQ (50%) 30 nm E4 HIL1 5 nm HTM1 140 nm NPB 20 nm H1 (95%): SEB4 (3%) 20 nm ETM1 (50%): LiQ (50%) 30 nm E5 HIL1 5 nm HTM1 140 nm NPB 20 nm H1 (95%): SEB5 (3%) 20 nm ETM1 (50%): LiQ (50%) 30 nm E6 HIL1 5 nm HTM1 140 nm NPB 20 nm H1 (95%): SEG1 (3%) 20 nm ETM1 (50%): LiQ (50%) 30 nm E7 HIL1 5 nm HTM1 140 nm NPB 20 nm H1 (95%): SEG2 (3%) 20 nm ETM1 (50%): LiQ (50%) 30 nm Vsol HILsol 20 nm - - Hsol (95%): SEBV1 (5%) 50 nm ETM1 (50%): LiQ (50%) 20 nm Esol HILsol 20 nm - - Hsol (95%): SEBsol (5%) 50 nm ETM1 (50%): LiQ (50%) 20 nm Table 2: Data for the OLEDs Example EQE at 1000 cd / m ² Voltage for 1000 cd / m ² CIE x / y at 1000 cd / m2 LD70 @ 50 mA / cm ² % [V] x y [H] V1 5.9% 4.7 0.145 0.166 50 E1 5.8% 4.6 0.138 0.144 50 E2 4.6% 4.7 0,139 0.109 40 E3 6.2% 4.7 0.144 0.172 90 E4 4.9% 4.9 0.140 0.094 50 E5 3.9% 4.8 0.144 0.126 50 E6 5.0% 4.9 0,278 0,575 180 E7 6.5% 4.6 0.282 0,577 220 Vsol 3.6% 5.7 0,136 0.156 20 Esol 4.9% 5.2 0,137 0.144 30 Table 3: Structural formulas of the materials of the OLEDs

Claims (12)

Compounds of the formula (1)

where the following applies to the symbols and indices used: Y represents an electron-donating group; X is the same or different at each occurrence and represents F, Cl, -P (= O) (Ar) ₂ , -SO ₂ Ar, -SOAr or CN; characterized in that X must be orthogonal to the Y; Ar is the same or different at each occurrence and is an aromatic or heteroaromatic ring system having from 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R ¹ , wherein two Ar may be joined together by a group E; E is the same or different on each occurrence and is a single bond, N (R ¹ ), o, S, C (R ¹ ) ₂ , C (R ¹ ) ₂ -C (R ¹ ) ₂ or Si (R ¹ ) ₂ ; W is the same or different CR ¹ or N at each occurrence, when W has no substituent X or Y; and W is C when W has a substituent X or Y; R ¹ is the same or different at each occurrence as H, D, F, Cl, Br, I, CN, NO ₂ , B (OR ² ) ₂ , Si (R ² ) ₃ , a straight-chain alkyl, alkoxy or thioalkoxy group 1 to 40 carbon atoms or a straight-chain alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms, each represented by a or several radicals R ² can be substituted, where one or more non-adjacent CH ₂ groups by -R ² C = CR ² -, -C≡C-, Si (R ² ) ₂ , Ge (R ² ) ₂ , Sn (R ² ) ₂ , C = O, C = S, C = S, C = Se, C = NR ² , -O-, -S-, -COO- or -CONR ² - may be replaced and where one or several H atoms may be replaced by F, Cl, Br, I, CN or NO ₂ , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one or more non-aromatic radicals R ¹ , or an aryloxy or heteroaryloxy group having from 5 to 40 aromatic ring atoms en, which may be substituted by one or more non-aromatic radicals R ¹ , or a combination of these systems; two or more substituents R ¹ can here also form a mono- or polycyclic ring system with each other; R ² each time identically or differently represents H, D, F or an aliphatic or aromatic hydrocarbon radical having 1 to 20 C atoms; n stands for each occurrence the same or different for 0 or 1. Compounds according to claim 1, characterized in that the index n = 1. Compounds according to claim 1 or 2, characterized in that W represents CH, when W has no substituent Y or X; and WC means when W has a substituent Y or X. Compounds according to one or more of Claims 1 to 2, selected from compounds of one of the formulas (2) to (3)

where the symbols and indices used have the meanings mentioned in claim 1 or 2. Compounds according to one or more of Claims 1 to 3, selected from compounds of one of the formulas (4) to (7)

where the symbols and indices used have the meanings given in claim 1 and where the compounds in all free positions can be substituted by groups R ¹ . Compounds according to one or more of claims 1 to 5, characterized in that X is the same or different CN or F at each occurrence. Compounds according to one or more of claims 1 to 6, characterized in that Y is the same or different at each occurrence -N (Ar) ₂ , -P (Ar) ₂ , -OAr or -SAr means. Use of compounds according to one or more of claims 1 to 7 in electronic devices, in particular in organic electroluminescent devices. Organic electronic devices comprising at least one compound according to one or more of Claims 1 to 7, in particular selected from the group consisting of organic field-effect transistors (O-FETs), organic thin-film transistors (O-FETs) and organic thin-film transistors (O-FETs). TFTs), organic light-emitting transistors (O-LETs), organic integrated circuits (O-ICs), organic solar cells (O-SCs), organic field quench devices (organic field-quench devices - O-FQDs), light-emitting electrochemical cells (LECs), organic electroluminescent devices (OLEDs), organic photoreceptors or organic laser diodes (O-lasers). The organic electroluminescent device of claim 9, comprising at least a cathode, an anode, an organic layer located between the cathode and anode, wherein the organic layer contains at least one host material and a compound according to one or more of claims 1 to 7. A process for the preparation of a compound according to one or more of claims 1 to 7, comprising a) carrying out a bromination of a pyrene derivative, b) optionally, carrying out a separation to isolate the desired isomer; c) performing a Buchwald-Hartwig coupling reaction with an arylamine; d) carrying out a bromination and a cyanation of the diaminopyrene derivative. A process for the preparation of a compound according to one or more of claims 1 to 7, comprising a) carrying out a boration step to give a pyrene-2,7-bis (boronate) ester, b) carrying out a bromination step in which Br is introduced into the positions of boron, c) carrying out a Buchwald-Hartwig coupling reaction with an arylamine, d) carrying out a bromination, e) optionally carrying out a separation to separate off the desired isomer, f) performing a cyanation step.