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.

##STR00001##

Claims

1.-19. (canceled)

20. A compound of the formula (1), ##STR00502## where the following applies to the symbols and indices used: A stands for a group of formula (A-1), (A-2) or (A-3), ##STR00503## where the dashed bonds represent the bonds to the rest of the formula (1); Z stands, on each occurrence, identically or differently, for CR.sup.Z or N; Z.sup.1, Z.sup.3, Z.sup.4 correspond to Z; with the proviso that, when n?1, then the group Ar.sup.L is bonded to one of the group Z.sup.1, Z.sup.3, Z.sup.4, which stands for C in this case and when n=0, then the group Ar.sup.L is absent and the carbazole moiety represented in formula (1) is directly bonded via its nitrogen atom to one of the groups Z.sup.1, Z.sup.3, Z.sup.4, which stands for C in this case; X stands, on each occurrence, identically or differently, for CR.sup.X or N; X.sup.1, X.sup.2, X.sup.3, X.sup.4 correspond to X; with the proviso that the group NAr.sup.1Ar.sup.1 as depicted in formula (1) is bonded to one of the groups X.sup.1, X.sup.2, X.sup.3, X.sup.4, which stands for C in this case; Ar.sup.L stands on each occurrence, identically or differently, for an aromatic ring system having 6 to 40 aromatic ring atoms and which may be substituted by one or more R radicals, or for an heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which may be substituted by one or more R radicals; Ar.sup.1 stands on each occurrence, identically or differently, for an aromatic ring system having 6 to 60 aromatic ring atoms and which may be substituted by one or more R radicals, or for an heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which may be substituted by one or more R radicals; R.sup.A, R.sup.X, R.sup.Z 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).sub.3, B(OR).sub.2, OSO.sub.2R, a straight-chain alkyl, alkoxy or thioalkyl group 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, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by RC?CR, C?C, Si(R).sub.2, Ge(R).sub.2, Sn(R).sub.2, C?O, C?S, C?Se, P(?O)(R), SO, SO.sub.2, O, S or CONR 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 system having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R, an aryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, or an aralkyl or heteroaralkyl group which has 5 to 60 aromatic ring atoms, which may be substituted by one or more R radicals; where two adjacent radicals R.sup.A, two adjacent radicals R.sup.X, two adjacent radicals R.sup.Z may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R; R 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).sub.3, B(OR).sub.2, OSO.sub.2R, a straight-chain alkyl, alkoxy or thioalkyl group 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, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by RC?CR, C?C, Si(R).sub.2, Ge(R).sub.2, Sn(R).sub.2, C?O, C?S, C?Se, P(?O)(R), SO, SO.sub.2, O, S or CONR 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 system having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R, or an aryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, where two adjacent radicals R may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R; Ar is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which may in each case also be substituted by one or more radicals R; R stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl group 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; and n is 0, 1, 2 or 3.

21. The compound according to claim 20, wherein it is selected from compounds of the formula (2), (3) or (4), ##STR00504## where the symbols have the same meaning as in claim 20.

22. The compound according to claim 20, wherein it is selected from compounds of one of the formulae (2-1) to (4-2), ##STR00505## ##STR00506## where the symbols have the same meaning as in claim 20.

23. The compound according to claim 20, wherein Z is CR.sup.Z.

24. The compound according to claim 20, wherein X is CR.sup.X.

25. The compound according to claim 20, wherein n is 0 or 1.

26. The compound according to claim 20, wherein it is selected from the compounds of one of the formulae (2-1-1) to (4-2-2), ##STR00507## ##STR00508## ##STR00509## ##STR00510## where the symbols have the same meaning as in claim 20.

27. The compound according to claim 20, wherein it is selected from the compounds of one of the formulae (2-1-1-1) to (4-2-2-4), ##STR00511## ##STR00512## ##STR00513## ##STR00514## ##STR00515## ##STR00516## ##STR00517## ##STR00518## ##STR00519## ##STR00520## ##STR00521## ##STR00522## ##STR00523## where the symbols have the same meaning as in claim 20.

28. The compound according to claim 20, wherein R.sup.A, R.sup.X and R.sup.Z stand on each occurrence, identically or differently, for H, D, F, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by RC?CR, C?C, O or S and where one or more H atoms may be replaced by D, F, Cl or CN, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may in each case be substituted by one or more radicals R; where two adjacent radicals R.sup.X, two adjacent radicals R.sup.Z, two adjacent radicals R.sup.A may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R.

29. The compound according to claim 20, wherein R.sup.X stands on each occurrence, identically or differently, for H, a straight-chain alkyl group having 1 to 20 C atoms, each of which may be substituted by one or more radicals R, or an aromatic ring system having 5 to 40 aromatic ring atoms or an heteroaromatic ring system having 5 to 40, each of which may be substituted by one or more radicals R; where two adjacent radicals R.sup.X may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R.

30. The compound according to claim 20, wherein R.sup.Z stands on each occurrence, identically or differently, for H, a straight-chain alkyl group having 1 to 20 C atoms or a branched alkyl group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R, or an or an aromatic ring system having 6 to 40 aromatic ring atoms or an heteroaromatic ring system having 5 to 40, each of which may be substituted by one or more radicals R; where two adjacent radicals R.sup.Z may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R.

31. The compound according to claim 20, wherein Ar.sup.L is selected, identically or differently, from benzene, biphenyl, terphenyl, naphthalene, fluorene, indenofluorene, spirobifluorene, triazine, benzoquinoline, benzoquinazoline, dibenzofuran, dibenzothiophene, and carbazole, where each of the above-mentioned groups may be substituted by one or more radicals R.

32. The compound according to claim 20, wherein Ar.sup.1 is on each occurrence, identically or differently, selected from phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, fluorenyl, benzofluorenyl, spirobifluorenyl, indenofluorenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, benzofuranyl, benzothiophenyl, benzofused dibenzofuranyl, benzofused dibenzothiophenyl, benzimidazo-benzimidazolyl, naphthyl-substituted phenyl, fluorenyl-substituted phenyl, spirobifluorenyl-substituted phenyl, dibenzofuranyl-substituted phenyl, dibenzothiophenyl-substituted phenyl, benzimidazobenzimidazolyl-substituted phenyl and carbazolyl-substituted phenyl, each of which may optionally be substituted by one or more radicals R.

33. A process for preparation of a compound according to claim 20, wherein it comprises the following steps: i) coupling reaction of a diarylamine with a carbazole having a reactive group, to obtain a diarylamine-carbazole derivative; ii) coupling reaction of the diarylamine-carbazole derivative obtained in step i) with a 9,9-spirobifluorene or 9,9-fluorene.

34. An oligomer, polymer or dendrimer, comprising a compound according to claim 20, where the bond(s) to the polymer, oligomer or dendrimer may be localised at any desired positions in formula (1) substituted by R.sup.X, R.sup.Z or R.

35. A formulation, comprising a compound according to claim 20 and at least one solvent.

36. An electronic device, comprising a compound according to claim 20.

37. The electronic device according to claim 36, wherein the device is an organic electroluminescent device, comprising anode, cathode and at least one emitting layer, where at least one organic layer of the device, which is a hole transport layer, an electron blocking layer or a hole injection layer, comprises the at least one compound.

38. A method comprising utilizing the compound according to claim 20 in an electronic device.

Description

EXAMPLES

A) Synthesis Examples

[0139] All reactions are carried out under nitrogen and by using dried solvents unless stated otherwise.

Example 1: Preparation of Compound (V)

Synthetic Procedure for the Preparation of Compound (V):

[0140] ##STR00418##

Preparation of Compound (III)

[0141] 25.0 g (0.1 mol) of compound (I) and 32 g (0.1 mol) of compound (II) are suspended in 500 mL of toluene under Ar atmosphere. 1.1 g (0.05 mol) of Pd(OAc).sub.2 are added to the flask and stirred under Ar atmosphere then 2.0 mL of a 1 M tri-tert-butylphosphine solution and 57.6 g (0.6 mol) of sodium t-butoxide are added to the flask. The reaction mixture is stirred under reflux for 24 h. After cooling, the organic phase is separated off, washed three times with 200 mL of water, dried over magnesium sulfate, filtered and subsequently evaporated to dryness. The residue is purified by column chromatography on silica gel using a mixture of ethylacetate/heptane (1:3). The yield is 39.0 g (0.08 mol), corresponding to 80% of theory.

Preparation of Compound (V)

[0142] 39.0 g (0.08 mol) of compound (III) and 31.6 g (0.08 mol) of compound (IV) are suspended in 500 mL of toluene under Ar atmosphere. 1.1 g (0.05 mol) of Pd(OAc).sub.2 are added to the flask and stirred under Ar atmosphere then 2.0 mL of a 1 M tri-tert-butylphosphine solution and 57.6 g (0.6 mol) of sodium t-butoxide are added to the flask. The reaction mixture is stirred under reflux for 24 h. After cooling, the organic phase is separated off, washed three times with 200 mL of water, dried over magnesium sulfate, filtered and subsequently evaporated to dryness. The residue is purified by column chromatography on silica gel using a mixture of ethylacetate/heptane (1:3). The yield is 60.0 g (0.075 mol), corresponding to 75% of theory.

[0143] The following compounds can be obtained analogously:

TABLE-US-00003 Bromo-carbazole Amine Bromide Product [00419] [00420] [00421] [00422] [00423] [00424] [00425] [00426] [00427] [00428] [00429] [00430] [00431] [00432] [00433] [00434] [00435] [00436] [00437] [00438] [00439] [00440] [00441] [00442] [00443] [00444] [00445] [00446] [00447] [00448] [00449] [00450] [00451] [00452] [00453] [00454]

Example 2: Preparation of Compound (VII)

Synthetic Procedure for the Preparation of Compound (VII):

[0144] ##STR00455##

Preparation of Compound (VII)

[0145] 48.6 g (0.1 mol) of compound (III) and 39.7 g (0.1 mol) of compound (VI) are suspended in 500 mL of toluene under Ar atmosphere. 1.1 g (0.05 mol) of Pd(OAc).sub.2 are added to the flask and stirred under Ar atmosphere then 2.0 mL of a 1 M tri-tert-butylphosphine solution and 57.6 g (0.6 mol) of sodium t-butoxide are added to the flask. The reaction mixture is stirred under reflux for 24 h. After cooling, the organic phase is separated off, washed three times with 200 mL of water, dried over magnesium sulfate, filtered and subsequently evaporated to dryness. The residue is purified by column chromatography on silica gel using a mixture of ethylacetate/heptane (1:3). The yield is 62.0 g (0.077 mol), corresponding to 77% of theory.

[0146] The following compounds can be obtained analogously:

TABLE-US-00004 Bromo-carbazole Amine Bromide Product [00456] [00457] [00458] [00459] [00460] [00461] [00462] [00463] [00464] [00465] [00466] [00467] [00468] [00469] [00470] [00471] [00472] [00473] [00474] [00475] [00476] [00477] [00478] [00479] [00480] [00481] [00482] [00483] [00484] [00485] [00486] [00487] [00488] [00489] [00490] [00491]

B) Device Examples

[0147] OLED devices are prepared according to the following process:

[0148] The substrates used are glass plates coated with structured ITO (indium tin oxide) in a thickness of 50 nm. The OLEDs have the following layer structure: substrate/hole-injection layer (HIL)/hole-transport layer (HTL)/hole-injection layer (HTL2)/electron-blocking layer (EBL)/emission layer (EML)/electron-transport layer (ETL)/electron-injection layer (EIL) and finally a cathode. The cathode is formed by an aluminium layer with a thickness of 100 nm. The precise structure of the prepared OLEDs is shown in Table 1. The materials required for the production of the OLEDs are shown in Table 3.

[0149] All materials are evaporated by thermal vapour deposition in a vacuum chamber. The emission layer always consists of minimum one matrix material (host material) and an emitting dopant (emitter), which is admixed with the matrix material or matrix materials in a certain proportion by volume by coevaporation. An expression such as H1:SEB (5%) denotes that material H1 is present in the layer in a proportion by volume of 95% and SEB is present in the layer in a proportion of 5%. Analogously, other layers may also consist of a mixture of two or more materials.

[0150] The OLEDs are characterized by standard methods. For this purpose, the electroluminescence spectra and the external quantum efficiency (EQE, measured in percent) as a function of the luminous density, calculated from current/voltagelluminous density characteristic lines (IUL characteristic lines) assuming Lambertian emission characteristics, and the lifetime are determined. The expression EQE @ 10 mA/cm.sup.2 denotes the external quantum efficiency at an operating current density of 10 mA/cm.sup.2. LT80 @ 60 mA/cm.sup.2 is the lifetime until the OLED has dropped from its initial luminance of i.e. 5000 cd/m.sup.2 to 80% of the initial intensity, i.e. to 4000 cd/m.sup.2 without using any acceleration factor. The data for the various OLEDs containing inventive and comparative materials are summarised in Table 2.

[0151] Compounds according to the invention are suitable as HIL, HTL, EBL or matrix material in the EML in OLEDs. They are suitable as a single layer, but also as mixed component as HIL, HTL, EBL or within the EML.

[0152] Compared with compounds from prior art (V1 and V2), the samples comprising the compounds according to the invention (E1 and E2) exhibit bath higher efficiencies and also improved lifetimes in singlet blue emitting devices.

TABLE-US-00005 TABLE 1 Structure of the OLEDs HIL HTL HTL2 EBL EML ETL EIL Thickness/ Thickness/ Thickness/ Thickness/ Thickness/ Thickness/ Thickness/ Ex nm nm nm nm nm nm nm E1 HIM:F4TCNQ HIM (V):F4TCNQ(5%) (V) H1:SEB(5%) ETM:LiQ LiQ (5%) 160 nm 20 nm 10 nm 20 nm (50%) 1 nm 20 nm 30 nm E2 HIM:F4TCNQ HIM (VII):F4TCNQ(5%) (VII) H1:SEB(5%) ETM:LiQ LiQ (5%) 160 nm 20 nm 10 nm 20 nm (50%) 1 nm 20 nm 30 nm V1 HIM:F4TCNQ HIM (A):F4TCNQ(5%) (A) H1:SEB(5%) ETM:LiQ LiQ (5%) 160 nm 20 nm 10 nm 20 nm (50%) 1 nm 20 nm 30 nm V2 HIM:F4TCNQ HIM (B):F4TCNQ(5%) ((B) H1:SEB(5%) ETM:LiQ LiQ (5%) 160 nm 20 nm 10 nm 20 nm (50%) 1 nm 20 nm 30 nm

TABLE-US-00006 TABLE 2 Data for the OLEDs EQE LT80 Ex. @ 10 mA/cm.sup.2 @ 60 mA/cm.sup.2 E1 8.0 380 E2 8.3 370 V1 7.1 290 V2 7.1 290

TABLE-US-00007 TABLE 3 Structures of the materials used [00492] [00493] [00494] [00495] [00496] [00497] [00498] [00499] [00500] [00501]