MATERIALS FOR ORGANIC ELECTROLUMINESCENT DEVICES

Abstract

The present invention relates to compounds of the formula (1) which are suitable for use in electronic devices, in particular organic electroluminescent devices, and to electronic devices which comprise these compounds.

Claims

1.-16. (canceled)

17. A compound of the formula (1), ##STR00054## wherein W is CR.sup.1, CR.sup.2 or N; V is CR, N, and at least two adjacent groups V stand for a group of the formula (V-1), ##STR00055## X.sup.1, X.sup.2 are on each occurrence, identically or differently, selected from groups of formulae (X-1) to (X-9), ##STR00056## where the dashed bonds in formulae (X-1) to (X-9) indicate the bonds to the 5-membered ring comprising X.sup.1 or X.sup.2; R, R.sup.1 stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(Ar).sub.2, C(O)Ar, P(O)(Ar).sub.2, S(O)Ar, S(O).sub.2Ar, NO.sub.2, Si(R.sup.3).sub.3, B(OR.sup.3).sub.2, OSO.sub.2R.sup.3, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 40 C atoms or branched or a cyclic alkyl, alkoxy or thioalkyl groups having 3 to 40 C atoms, each of which may be substituted by one or more radicals R.sup.3, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by R.sup.3CCR.sup.3, CC, Si(R.sup.3).sub.2, Ge(R.sup.3).sub.2, Sn(R.sup.3).sub.2, CO, CS, CSe, P(O)(R.sup.3), SO, SO.sub.2, O, S or CONR.sup.3 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO.sub.2, an aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.3, or an aryloxy groups having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R.sup.3, where two radicals R and/or two radicals R.sup.1 may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R.sup.3; R.sup.2 stands on each occurrence, identically or differently, for C(O)Ar, P(O)(Ar).sub.2, S(O)Ar.sup.1, S(O).sub.2Ar.sup.1, SAr.sup.1, B(Ar.sup.1).sub.2 or P(Ar.sup.1).sub.2; R.sup.3 stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(Ar).sub.2, C(O)Ar, P(O)(Ar).sub.2, S(O)Ar, S(O).sub.2Ar, NO.sub.2, Si(R.sup.4).sub.3, B(OR.sup.4).sub.2, OSO.sub.2R.sup.4, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 40 C atoms, each of which may be substituted by one or more radicals R.sup.4, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by R.sup.4CCR.sup.4, CC, Si(R.sup.4).sub.2, Ge(R.sup.4).sub.2, Sn(R.sup.4).sub.2, CO, CS, CSe, P(O)(R.sup.4), SO, SO.sub.2, O, S or CONR.sup.4 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO.sub.2, an aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.4, or an aryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R.sup.4, where two radicals R.sup.3 may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R.sup.4; R.sup.4 stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by SO, SO.sub.2, O, S and where one or more H atoms may be replaced by D, F, Cl, Br or I, or an aromatic or heteroaromatic ring system having 5 to 24 C atoms; Ar, Ar.sup.1 are on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may in each case also be substituted by one or more radicals R.sup.4; and where both 6-membered rings comprising the groups W in formulae (1) and (V-1) carry at least one substituent R.sup.2.

18. The compound according to claim 17, wherein the compounds of formula (1) are selected from compounds of the following formulae (2) to (5), ##STR00057## where the symbols X.sup.1, X.sup.2, V, R and R.sup.2 have the same meaning as in claim 17, and where the index n is equal to 0, 1, 2 or 3.

19. The compound according to claim 17, wherein the compounds are selected from compounds of formulae (2a) to (5a), ##STR00058## where the symbols X.sup.1, X.sup.2, V, R.sup.1 and R.sup.2 and the index n have the same meaning as in claim 17.

20. The compound according to claim 17, wherein the compounds of formula (1) are selected from compounds of formulae (2b-1) to (5b-3), ##STR00059## ##STR00060## where the symbols X.sup.1, X.sup.2 and R.sup.2 have the same meaning as in claim 17.

21. The compound according to claim 17, wherein R.sup.2 is selected from P(O)(Ar).sub.2, S(O)Ar and S(O).sub.2Ar.sup.1.

22. The compound according to claim 17, wherein the group Ar.sup.1 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system selected from benzene, naphthalene, anthracene, biphenyl, terphenyl, fluorene, furan, benzofuran, dibenzofuran, thiophene, benzothiophene, dibenzothiophene, carbazole, indolocarbazole, indenocarbazole or pyridine, each of which may be substituted by one or more radicals R.sup.4 at any free positions.

23. The compound according to claim 17, wherein the group Ar.sup.1 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system selected from benzene, naphthalene, anthracene, biphenyl, terphenyl, fluorene, each of which may be substituted by one or more radicals R.sup.4 at any free positions.

24. The compound according to claim 17, wherein the group Ar.sup.1 is substituted by at least one fluorine atom or at least one straight-chain fluoroalkyl group having 1 to 20 C atom, or branched or cyclic fluoroalkyl groups having 3 to 20 C atoms.

25. The compound according to claim 17, wherein X.sup.1 and X.sup.2 are on each occurrence, identically or differently, selected from a group of formula (X-1), (X-2) or (X-9) as defined in claim 17.

26. The compound according to claim 25, wherein X.sup.1 stands for (X-1) and X.sup.2 stands for (X-9) or in that X.sup.1 stands for (X-9) and X.sup.2 stands for (X-1).

27. The compound according to claim 25, wherein X.sup.1 and X.sup.2 both stand for a group of formula (X-1) as defined in claim 17.

28. A formulation comprising at least one compound according to claim 17 and at least one solvent.

29. An electronic device comprising the least one compound according to claim 17, selected from the group consisting of organic electroluminescent devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, dye-sensitised organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, organic laser diodes and organic plasmon emitting devices.

30. The electronic device according to claim 29, which is an organic electroluminescent device, wherein the compound is a hole-injection material in a hole-injecting layer or as a p-dopant in a hole-injecting or in a hole-transporting layer.

31. The electronic device according to claim 30, wherein the organic electroluminescent device comprises a cathode, an anode, at least one emitting layer arranged between the anode and the cathode, at least one hole-transport layer arranged between the anode and the at least one emitting layer and at least one hole-injection layer arranged between the anode and the at least one hole-transport layer, wherein the at least one hole-injection layer comprises an electron acceptor material comprising the at least one compound.

32. The electronic device according to claim 30, wherein the organic electroluminescent device comprises a cathode, an anode, at least one emitting layer arranged between the anode and the cathode, at least one hole-transport layer arranged between the anode and the at least one emitting layer and at least one hole-injection layer arranged between the anode and the at least one hole-transport layer, wherein the at least one hole-injection layer or the at least one hole-transport layer comprises a p-dopant comprising the at least one compound.

Description

WORKING EXAMPLES

A) Synthesis Examples

Example 1

3,9-Bis(phenylsulfonyl)-6,12-bis(dicyanomethylene)indeno[1,2-b]fluorene

a) 4,4-Dibromo-[1,1;4,1 ]terphenyl-2,2-dicarboxylic acid dimethyl ester

[0113] ##STR00044##

[0114] 1,3-Phenylenediboronic acid (17.04 g, 102.8 mmol), 5-bromo-2-iodo-benzoic acid methyl ester (77.1 g, 226.2 mmol), Pd(PPh.sub.3).sub.4 (11.9 g, 10.3 mmol) and K.sub.2CO.sub.3 (55.8 g, 411.2 mmol) are dissolved in toluene (700 ml), ethanol (400 ml) and water (250 ml) under inert atmosphere. The reaction is degassed and heated to 70 C. for four days. After the reaction is stopped and cooled down, the reaction mixture is then poured into water (600 ml), stirred vigorously, and finally the layers are separated. The aqueous layer is extracted with ethyl acetate (2200 ml). The combined organic layers are washed with brine (150 ml) and dried over MgSO.sub.4. The product is concentrated in vacuo and the crude product is obtained as a yellow liquid. The mixture is purified by flash chromatography on silica gel with heptane and dichloromethane (1:2 respectively) as eluent. The product (31.4 g, 62.3 mmol, 61%) is obtained as white solid.

[0115] LC-APLI-MS (100 Hz, pos.): 92.1%, m/z=501.9 (M.sup.+)

b) Dimethyl 4,4-bis(phenylsulfonyl)-[1,1:4,1-terphenyl]-2,2-dicarboxylate

[0116] ##STR00045##

[0117] 4,4-Dibromo-[1,1;4,1 ]terphenyl-2,2-dicarboxylic acid dimethyl ester (25 g, 49.6 mmol), sodium benzenesulfinate (17.9 g, 109.1 mmol), Xantphos (1.43 g, 2.48 mmol), Pd.sub.2(dba).sub.3 (1.36 g, 1.49 mmol), CsCO.sub.3 (24.2 g, 74.4 mmol) and Bu.sub.4NC*H.sub.2O (16.5 g, 59.5 mmol) are dissolved in toluene (1 L) under argon. The solution is degassed and subsequently heated up to 105 C. for three days. After cooling to room temperature the reaction mixture is poured into water (300 ml), stirred vigorously, and finally the layers are separated. The aqueous layer is extracted with DCM (2200 ml). The combined organic layers are concentrated and the crude product is recrystallized from heptane, DCM and toluene. The product (19.1 g, 30.5 mmol, 62%) is obtained as bright yellow solid.

[0118] APCI-MS (neg.) m/z=626.3 (M.sup.)

[0119] FT-IR (ATR)=1726 cm.sup.1 (OCO), 1242 cm.sup.1 (OCO)

c) 3,9-Bis(phenylsulfonyl)indeno[1,2-b]fluorene-6,12-dione

[0120] ##STR00046##

[0121] Dimethyl 4,4-bis(phenylsulfonyl)-[1,1:4,1-terphenyl]-2,2-dicarboxylate (15.3 g, 24.4 mmol) is dissolved in conc. H.sub.2SO.sub.4 (500 ml). The mixture is heated up to 75 C. overnight, and the solution color was dark red. The reaction progress was followed via FT-IR (ATR) measurements. When the reaction is stopped, it is cooled to room temperature, then the reaction mixture is poured slowly into iced water. The fine solid is filtered off, washed with a large amount of water and dichloromethane, and dried in vacuo at 60 C. The product is obtained as a dark brown solid (9.37 g, 16.7 mmol, 68%).

[0122] MALDI-TOF-MS (DHB, 100 Hz, neg.)=562 (100%, M.sup.1)

[0123] FT-IR (ATR)=1716 cm.sup.1 (CO)

d) 3,9-Bis(phenylsulfonyl)-6,12-bis(dicyanomethylene)indeno[1,2-b]fluorene

[0124] ##STR00047##

[0125] 3,9-Bis(phenylsulfonyl)indeno[1,2-b]fluorene-6,12-dione (250 mg, 0.44 mmol), with malononitrile (191 mg, 2.9 mmol) are dissolved in pyridine (5 ml) and toluene (20 ml). The mixture is heated up to 180 C. overnight. After the reaction is finished, it is concentrated and the remaining crystals are washed with heptane and dichloromethane. The product is obtained as a dark brown solid (143 mg, 0.22 mmol, 49%). It is further purified via sublimation.

[0126] MALDI-TOF-MS (DHB, 100 Hz, neg.)=658 (M.sup.), 696 ([M.sup.+H+K].sup.+)

[0127] FT-IR (ATR)=2209 cm.sup.1 (CN)

Example 2

2,8-Bis(phenylsulfonyl)-10,12-bis(dicyanomethylene)indeno[2,1-b]fluorene

a) Methyl 2-bromo-5-(phenylsulfonyl)benzoate

[0128] ##STR00048##

[0129] Reaction is carried out in analogy of Chem. Cat. Chem. 2015, 7, 1539-1542. Preparation of the catalyst: Cu(I)Br (2.00 g, 14 mmol) and 1,10-phenanthroline (2.51 g, 14 mmol) are dissolved in dichloromethane (70 ml) under argon. Stirring is continued for 2 h at room temperature. The solvent is removed in vacuo and the catalyst phenCu(I)Br is obtained as a solid and is directly used in the next reaction.

[0130] Methyl 2-bromo-5-(chlorosulfonyl)benzoate (40 g, 128 mmol), phenyl boronic acid (18.7 g, 153 mmol), K.sub.2CO.sub.3 (35.3 g, 255 mmol) and phenCu(I)Br (4.44 g, 14 mmol) are dissolved in dichloromethane (1.6 l) and water (20 ml) under ambient conditions. Stirring is continued at room temperature for three days. The reaction mixture is then poured into water (500 ml) and the layers are separated. The aqueous layer is extracted with dichloromethane (3100 ml). The combined organic layers are washed with brine (100 ml) and dried over MgSO.sub.4. The solvent is removed in vacuo and the crude product (35.7 g) is purified by silica column chromatography with dichloromethane/heptane (2:1) as eluent. The product (19.0 g, 53.3 mmol, 42%) is obtained as white solid. GC-MS (EI, 70 eV)=356/354 (60%), 325/323 (70%), 263/261 (30%), 125 (100%), 77 (70%)

b) Dimethyl 4,4-bis(phenylsulfonyl)-[1,1:3,1-terphenyl]-2,2-dicarboxylate

[0131] ##STR00049##

[0132] Methyl 2-bromo-5-(phenylsulfonyl)benzoate (17.6 g, 49.5 mmol), 1,3-phenylenediboronic acid (3.91 g, 23.6 mmol), K.sub.3PO.sub.4 (20.0 g, 94.4 mmol) and Pd(PPh.sub.3).sub.4 (2.18 g, 1.9 mmol) are dissolved in toluene (700 ml), ethanol (400 ml) and water (300 ml) under argon. The solution is degassed and subsequently heated up to 65 C. for two days. After cooling to room temperature the reaction mixture is poured into water (200 ml). The layers are separated and the aqueous layer is extracted with toluene (3100 ml). The combined organic layers are washed with brine and dried over MgSO.sub.4. The solvent is removed in vacuo and the crude product is obtained as a glue like material. It is further purified using silica column chromatography with heptane and ethyl acetate as eluent. The product (9.35 g, 14.9 mmol, 63%) is obtained as yellow solid.

[0133] GC-MS (EI, 70 eV)=626 (50%, M.sup.+), 563 (100%)

[0134] FT-IR (ATR, neat)=1728 cm.sup.1 (CO)

c) 2,8-Bis(phenylsulfonyl)indeno[2,1-b]fluorene-10,12-dione

[0135] ##STR00050##

[0136] Dimethyl 4,4-bis(phenylsulfonyl)-[1,1:3,1-terphenyl]-2,2-dicarboxylate (8.5 g, 13.6 mmol) and conc. sulfuric acid (170 ml) are heated to 90 C. with stirring for two days. The reaction mixture is cooled to room temperature and is poured into iced water. The yellow precipitate is collected by filtration and it is washed with water and heptane. It is dried in vacuo and the crude product is collected as yellow solid. The crude product is purified via silica column chromatography with heptane and ethyl acetate.

[0137] MALDI-MS (DHB, 100 Hz, pos.)=562 (100%, M.sup.1)

[0138] FT-IR (ATR, neat)=1704, 1720 cm.sup.1 (CO)

d) 2,8-Bis(phenylsulfonyl)-10,12-bis(dicyanomethylene)indeno[2,1-b]fluorene

[0139] ##STR00051##

[0140] Crude 2,8-bis(phenylsulfonyl)indeno[2,1-b]fluorene-10,12-dione (7.2 g, 12.8 mmol) and malonodinitrile (5.1 g, 76.8 mmol) are dissolved in pyridine (200 ml). The reaction mixture is heated to 65 C. for 5 h. After cooling to room temperature the precipitate is filtered off. The crude product is washed with water, heptane and dichloromethane and it is dried in vacuo. The crude product is obtained as orange powder. It is further purified via sublimation.

[0141] MALDI-MS (DHB, 100 Hz, neg.)=658 (100%, M.sup.+)

[0142] FT-IR (ATR, neat)=2224 cm.sup.1 (CN)

Example 3

(2,9-Bis(phenylsulfonyl)-7-(dicyanomethylene))indeno[1,2-a]fluorene-12-one a) 2,9-Bis(phenylsulfonyl)indeno[1,2-a]fluorene-7,12-dione

[0143] ##STR00052##

[0144] Dimethyl 4,4-bis(phenylsulfonyl)-[1,1:3,1-terphenyl]-2,2-dicarboxylate (8.5 g, 13.6 mmol) and conc. sulfuric acid (170 ml) are heated to 90 C. with stirring for two days. The reaction mixture is cooled to room temperature and is poured into iced water. The yellow precipitate is collected by filtration and it is washed with water and heptane. It is dried in vacuo and the crude product is collected as yellow solid. The crude product is purified via silica column chromatography with heptane and ethyl acetate.

[0145] MALDI-MS (DHB, 100 Hz, pos.)=562 (100%, M.sup.+)

[0146] FT-IR (ATR, neat)=1714 cm.sup.1 (CO)

b) (2,9-Bis(phenylsulfonyl)-7-(dicyanomethylene))indeno[1,2-a]fluorene-12-one

[0147] ##STR00053##

[0148] Crude 2,8-bis(phenylsulfonyl)indeno[2,1-b]fluorene-10,12-dione (7.2 g, 12.8 mmol) and malonodinitrile (5.1 g, 76.8 mmol) are dissolved in pyridine (200 ml). The reaction mixture is heated to 65 C. for 5 h. After cooling to room temperature the precipitate is filtered off. The crude product is washed with water, heptane and dichloromethane and it is dried in vacuo. The crude product is obtained as orange powder. It is further purified via sublimation.

[0149] MALDI-MS (DHB, 100 Hz, neg.)=610 (100%, M.sup.+)

[0150] FT-IR (ATR, neat)=2224 cm.sup.1 (CN), 1711 cm.sup.1 (CO)

B) Fabrication of OLEDs

[0151] Substrate Pre-Treatment:

[0152] The substrates used are glass plates coated with structured ITO (indium tin oxide) with a thickness of 50 nm.

[0153] Freshly cleaned substrates are transferred into the evaporation tool. Here the substrates are either preconditioned with oxygen plasma for 130 s and afterwards treated with argon plasma for 150 s (Oxygen Argon) or only preconditioned with oxygen plasma for 130 s (Oxygen).

[0154] Afterwards several organic layers are deposited by physical vapour deposition. The thickness of the layers is determined by reference experiments, where thick layers of roughly 100 nm organic material are deposited. The thickness is measured during the evaporation by a thin-film thickness monitor, based on quartz crystal microbalance, e.g. Inficon. The organic layer is protected by evaporation of a thin aluminium film on top. Then the real thickness of the organic layer is measured by a surface profiler, e.g. K-LA-Tencor P7. The tooling factor of the thin-film monitor is adapted in a way that the film thickness of the surface profiler and the thin film monitor is the same.

[0155] The devices basically have the following layer structure: substrate/hole-injection layer (HIL)/hole-transport layer (HTL) and finally a cathode, or: substrate/HTM:HIM (X %)/hole-transport layer (HTL) and finally a cathode. The cathode is formed by an aluminium layer with a thickness of 100 nm.

[0156] All materials are applied by thermal vapour deposition in a vacuum chamber. An expression such as HTM:HIM (X %) here means that material HTM is present in the layer in a proportion by volume of (100X) % and HIM is present in the layer in a proportion of X %.

[0157] Use of Inventive Compounds as HIL Material in Hole Only Devices:

[0158] The devices are hole-only devices in which the inventive compounds of Examples 1, 2 and 3 are used in the HIL. It can be shown, that lowered voltages can be obtained with HILs made of the inventive compounds compared to devices without HIL.