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.-18. (canceled)

19. A compound of formula (1): ##STR00458## where the following applies to the symbols and indices used: Ar.sup.1, Ar.sup.2 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 C aromatic ring atoms, which may in each case also be substituted by one or more radicals R.sup.5, Ar.sup.1 and Ar.sup.2 here may also be connected to one another by a group E; E is on each occurrence, identically or differently, a single bond, N(R.sup.5), O, S, C(R.sup.5).sub.2, C(R.sup.5).sub.2—C(R.sup.5).sub.2, Si(R.sup.5).sub.2 or B(R.sup.5); R.sup.1, R.sup.2, R.sup.3, R.sup.4 are selected on each occurrence, identically or differently, from the group consisting of D, F, Cl, Br, I, CN, Si(R.sup.6).sub.3, N(R.sup.6).sub.2, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R.sup.6, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by Si(R.sup.6).sub.2, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S or CONR.sup.6 and where one or more H atoms may be replaced by D, F, Cl, Br or I, 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.sup.6, an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R.sup.6, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.6, where two or more adjacent substituents R.sup.1 or R.sup.2 or R.sup.3 or R.sup.4 may optionally form a mono- or polycyclic ring system, which may be substituted by one or more radicals R.sup.6; R is selected on each occurrence, identically or differently, from the group consisting of D, F, Cl, Br, I, CN, Si(R.sup.6).sub.3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R.sup.6, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by Si(R.sup.6).sub.2, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S or CONR.sup.6 and where one or more H atoms may be replaced by D, F, Cl, Br or I, 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.sup.6, an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R.sup.6, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.6, where two or more adjacent substituents R.sup.5 may optionally form a mono- or polycyclic ring system, which may be substituted by one or more radicals R.sup.6; R.sup.5 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, Cl, Br, I, CN, Si(R.sup.6).sub.3, N(R.sup.6).sub.2, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R.sup.6, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by Si(R.sup.6).sub.2, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S or CONR.sup.6 and where one or more H atoms may be replaced by D, F, Cl, Br or I, 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.sup.6, an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R.sup.6, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.6, where two or more adjacent substituents R.sup.5 may optionally form a mono- or polycyclic ring system, which may be substituted by one or more radicals R.sup.6; R.sup.6 is selected from the group consisting of H, D, F, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic or heteroaromatic ring system having 5 to 30 C atoms, in which one or more H atoms may be replaced by D or F, where two or more adjacent substituents R.sup.6 may form a mono- or polycyclic ring system with one another; m is 0, 1, 2 or 3; n is 0, 1, 2, 3 or 4; p, q are, identically or differently, 0 or 1; r, s are, identically or differently, 0, 1, 2, 3 or 4; where p+r≦4 and q+s≦4; t is, on each occurrence, identically or differently, 0, 1, 2 or 3.

20. The compound according to claim 19, selected from compounds of the following formulae (2) to (9), ##STR00459## ##STR00460## where the symbols and indices used are defined as in claim 19.

21. The compound according to claim 19, selected from compounds of the following formulae (2a) to (9a), ##STR00461## ##STR00462## where the symbols and indices used are defined as in claim 19.

22. The compound according to claim 19, selected from compounds of the following formulae (2b) to (9b), ##STR00463## ##STR00464## where m, n, r and s are, identically or differently, 0 or 1; and the other symbols used are defined as claim 19.

23. The compound according to claim 19, selected from compounds of the following formula (2c) or (9c), ##STR00465## ##STR00466## where m, n, r and s are, identically or differently, 0 or 1; and the other symbols used are defined as claim 19.

24. The compound according to claim 19, wherein at least one of the groups Ar.sup.1 and Ar.sup.2 is selected, identically or differently, on each occurrence, from phenyl, fluorenyl, spirobifluorenyl, biphenyl, terphenyl, quaterphenyl, carbazoyl, dibenzofuranyl and dibenzothiophenyl, each of which may be substituted by one or more radicals R.sup.5.

25. Compound according to claim 19, wherein at least one of the groups Ar.sup.1 and Ar.sup.2 are selected, identically or differently on each occurrence, from the groups of the following formulae (10) to (66), ##STR00467## ##STR00468## ##STR00469## ##STR00470## ##STR00471## ##STR00472## ##STR00473## ##STR00474## ##STR00475## where the dashed bond indicates the bond to the nitrogen, and the groups may be substituted by one or more radicals R.sup.5.

26. The compound according to claim 19, wherein the groups Ar.sup.1 and Ar.sup.2 are selected identically.

27. The compound according to claim 19, wherein the groups Ar.sup.1 and Ar.sup.2 are selected differently from one another.

28. The compound according to claim 19, wherein R.sup.1 to R.sup.4 are selected, identically or differently on each occurrence, from the group consisting of F, CN, a straight-chain alkyl or alkoxy group having 1 to 10 C atoms or a branched or cyclic alkyl or alkoxy group having 3 to 10 C atoms, each of which may be substituted by one or more radicals R.sup.6, where one or more non-adjacent CH.sub.2 groups may be replaced by O and where one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.6.

29. The compound according to claim 19, wherein the radical R.sup.5 which is bonded to Ar.sup.1 or Ar.sup.2 is selected, identically or differently on each occurrence, from the group consisting of H, F, CN, N(R.sup.6).sub.2, a straight-chain alkyl group having 1 to 10 C atoms, a branched or cyclic alkyl group having 3 to 10 C atoms or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R.sup.6.

30. The compound according to claim 19, wherein: Ar.sup.1, Ar.sup.2 are, identically or differently, a group of one of the formulae (10) to (66); or —NAr.sup.1Ar.sup.2 stands for a group of one of the formulae (67) to (74); ##STR00476## ##STR00477## ##STR00478## E is on each occurrence, identically or differently, a single bond or C(R.sup.5).sub.2, N(R.sup.5), O or S; R.sup.1 to R.sup.4 are selected, identically or differently on each occurrence, from the group consisting of H, F, CN, a straight-chain alkyl or alkoxy group having 1 to 10 C atoms or a branched or cyclic alkyl or alkoxy group having 3 to 10 C atoms, each of which may be substituted by one or more radicals R.sup.6, where one or more non-adjacent CH.sub.2 groups may be replaced by O and where one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.6; R is selected, identically or differently on each occurrence, from the group consisting of F, CN, a straight-chain alkyl or alkoxy group having 1 to 10 C atoms or a branched or cyclic alkyl or alkoxy group having 3 to 10 C atoms, each of which may be substituted by one or more radicals R.sup.6, where one or more non-adjacent CH.sub.2 groups may be replaced by O and where one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.6. R.sup.5 is, if the radical R.sup.5 is bonded to Ar.sup.1 or Ar.sup.2, selected, identically or differently on each occurrence, from the group consisting of H, F, CN, N(R.sup.6).sub.2, a straight-chain alkyl group having 1 to 10 C atoms, a branched or cyclic alkyl group having 3 to 10 C atoms or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R.sup.6; or R.sup.5 which is bonded to the carbon bridge in the formulae (20) to (23), (53), (54), (68) and (72) is, identically or differently, an alkyl group having 1 to 10 C atoms, or a phenyl group, which may be substituted by one or more radicals R.sup.6; or R.sup.5 which is bonded to the nitrogen bridge in the formulae (28) to (31), (40) to (43) or (55) to (58), (63) to (66), (71) and (73) is a phenyl group, which may be substituted by one or more radicals R.sup.6; R.sup.6 is selected on each occurrence, identically or differently, from the group consisting of H, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms or an aromatic ring system having 5 to 24 C atoms; m is 0 or 1; n is 0 or 1; p+q is 0 or 1; r is 0 or 1; s is 0 or 1; t is 0 or 1.

31. An oligomer, a polymers or a dendrimer comprising one or more compounds according to claim 19, where the bond(s) to the polymer, oligomer or dendrimers may be localised at any desired positions in formula (I).

32. A formulation comprising at least one compound according to claim 19 and at least one solvent.

33. A process for the preparation of a compound according to claim 19, comprising a C—C Suzuki coupling reaction between a spirobifluorene boronic ester derivative and an halogenated diaminobenzene.

34. A method comprising utilizing the compound according to claim 19 in an electronic device.

35. An electronic device comprising at least one compound according to claim 19, 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, organic dye-sensitised solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, organic laser diodes and organic plasmon emitting devices.

36. The electronic device according to claim 35, selected from organic electroluminescent devices, wherein the compound according to claim 19 is comprised as hole-transport material in a hole-transport or hole-injection or exciton-blocking or electron-blocking layer, or is comprised as matrix material for fluorescent or phosphorescent emitters in an emitting layer.

Description

EXAMPLES

A) Synthesis Examples

Examples

[0133] The following syntheses are carried out under a protective-gas atmosphere, unless indicated otherwise. The starting materials can be purchased from ALDRICH or ABCR. The numbers in square brackets in the case of the starting materials known from the literature are the corresponding CAS numbers.

Example 1

Synthesis of Compound (1-1)

[0134] ##STR00260##

Intermediate (A-1): Synthesis of N,N,N′,N′-Tetrakis-biphenyl-4-yl-5-chloro-benzene-1,3-diamine

[0135] Tri-tert-butylphosphine (11.1 mL of a 1.0 M solution in toluene, 11.1 mmol), palladium acetate (1.25 g, 5.55 mmol) and cesium carbonate (75.0 g, 232 mmol) are added to a solution of bis-biphenyl-4-yl-amine (CAS Nr. 102113-98-4) (59.0 g, 185 mmol) and 1,3-Dibromo-5-chloro-benzene (25 g, 92 mol) in degassed toluene (600 ml), and the mixture is heated under reflux for 2 h. The reaction mixture is cooled to room temperature, extended with toluene and filtered through Celite. The filtrate is evaporated in vacuo, and the residue is crystallised from heptane/toluene. Yield: 67.7 g, 75%.

[0136] The following compounds are obtained analogously:

TABLE-US-00003 Educt 1 Amine Product Yield A-2 [00261] [00262] [00263] 65% A-3 [00264] [00265] [00266] 71% A-4 [00267] [00268] [00269] 80% A-5 [00270] [00271] [00272] 80% A-6 [00273] [00274] [00275] 87% A-7 [00276] [00277] [00278] 76% A-8 [00279] [00280] [00281] 73% A-9 [00282] [00283] [00284] 70% A-10 [00285] [00286] [00287] 81% A-11 [00288] [00289] [00290] 83% A-12 [00291] [00292] [00293] 78% A-13 [00294] [00295] [00296] 68% A-14 [00297] [00298] [00299] 74% A-15 [00300] [00301] [00302] 61% A-16 [00303] [00304] [00305] 40% A-17 [00306] [00307] [00308] 71%

Intermediate (B-1): Synthesis of the Spirobifluorene-Boronester Derivatives

1a) Synthesis of 4-bromospiro-9,9″-bifluorene

[0137] ##STR00309##

[0138] 60 g (188.5 mmol) 2,2′-Dibromo-biphenyl (CAS 13029-09-9) is dissolved in 750 mL of dry THF and cooled down to −78° C. 75.4 mL (188.5 mmol) of a 2.5M solution of nBuLi in heptane is added dropwise. After 1 h a solution of 34.6 g of fluorenone (188.5 mmol) (CAS 486-25-9) in 250 mL of THF is added dropwise. The reaction mixture is allowed to reach the room temperature overnight, then quenched with saturated NH.sub.4Cl (100 mL) solution, the mixture is stirred briefly, the organic phase is separated off, and the solvent is removed in vacuum. The residue is suspended in 500 ml of glacial acetic acid at 40° C., 0.5 ml of conc. hydrochloric acid is added to the suspension, and the mixture is subsequently stirred at 100° C. for a further 2 h. After cooling, the precipitated solid is filtered off with suction, washed once with 100 ml of glacial acetic acid, three times with 100 ml of ethanol each time and finally recrystallized from dioxane. Yield: 70.1 g (169 mmol), 90%; purity about 98% according to .sup.1H-NMR.

[0139] The synthesis of further brominated spirobifluorene derivatives is carried out analogously:

TABLE-US-00004 Product: Br- Br-biphenyl Br-fluorenone spirobifluorene Yield 1b [00310] [00311] [00312] 85% 1c [00313] [00314] [00315] 68% 1d [00316] [00317] [00318] 85% 1e [00319] [00320] [00321] 91% 1f [00322] [00323] [00324] 90% 1g [00325] [00326] [00327] 78% 1h [00328] [00329] [00330] 75% 1i [00331] [00332] [00333] 71% 1j [00334] [00335] [00336] 68% 1k [00337] [00338] [00339] 70%

2a) Synthesis of 4-bromospiro-9,9′-bifluorene (B-1)

[0140] ##STR00340##

[0141] 60 g (152 mmol) 4-bromospiro-9,9′-bifluorene, 47.2 g (182.1 mmol) bis-pinacolatediboron, 3.72 g (4.55 mmol) 1,1′-bis(diphenylphosphino)ferrocene-palladium(II)dichloride dichloromethane complex, 44.7 (455 mmol) potassium acetate and 600 ml of toluene is heated under reflux for 16 h. After cooling, 200 ml of water are added, the mixture is stirred for a further 30 min., the organic phase is separated off, filtered through a short Celite bed, and the solvent is then removed in vacuum. The residue is recrystallised several times from heptanes/toluene. Yield: 67.1 g, 96%.

[0142] The synthesis of further spirobifluorene boronic ester derivatives is carried out analogously:

TABLE-US-00005 Br-spirobifluorene Product Yield B-2 [00341] [00342] 90% B-3 [00343] [00344] 67% B-4 [00345] [00346] 87% B-5 [00347] [00348] 85% B-6 [00349] [00350] 85% B-7 [00351] [00352] 90% B-8 [00353] [00354] 92% B-9 [00355] [00356] 85% B-10 [00357] [00358] 93% B-11 [00359] [00360] 92% B-12 [00361] [00362] 87%

Synthesis of Compound (1.1)

[0143] 392 mg (0.53 mmol) Palladium dichloride-bis(tricyclohexylphosphine), 39 μL hydrazinium hydroxide (0.8 mmol) and sodium metaborate (11 g, 40 mmol) are added to a solution of 20 g (27 mmol) of N,N,N′,N′-tetrakis-biphenyl-4-yl-5-chloro-benzene-1,3-diamine (A-1) and 10 g (28 mmol) 4-Spirobifluorenboronic ester (B1) in 430 mL THF, and the mixture is heated under reflux for 20 h. The reaction mixture is cooled to room temperature, extended with toluene and filtered through Celite. The filtrate is extended with water, re-extracted with toluene, and the combined organic phases are dried and evaporated in vacuum. The residue is recrystallised from heptane/toluene and sublimated in vacuum. Compound (1-1) is obtained in the form of a pale-yellow solid (21.0 g, 76% of theory).

[0144] The synthesis of compound 1-2 to 1-29 is carried out analogously. After recrystallisation the materials are sublimated or tempered under high vacuum.

TABLE-US-00006 Intermediate B Intermediate A 1-2 [00363] [00364] 1-3 [00365] [00366] 1-4 [00367] [00368] 1-5 [00369] [00370] 1-6 [00371] [00372] 1-7 [00373] [00374] 1-8 [00375] [00376] 1-9 [00377] [00378] 1-10 [00379] [00380] 1-11 [00381] [00382] 1-12 [00383] [00384] 1-13 [00385] [00386] 1-15 [00387] [00388] 1-16 [00389] [00390] 1-17 [00391] [00392] 1-18 [00393] [00394] 1-19 [00395] [00396] 1-20 [00397] [00398] 1-21 [00399] [00400] 1-22 [00401] [00402] 1-23 [00403] [00404] 1-24 [00405] [00406] 1-25 [00407] [00408] 1-26 [00409] [00410] 1-27 [00411] [00412] 1-28 [00413] [00414] 1-29 [00415] [00416] 1-30 [00417] [00418] Product Yield 1-2 [00419] 78% 1-3 [00420] 81% 1-4 [00421] 75% 1-5 [00422] 68% 1-6 [00423] 70% 1-7 [00424] 65% 1-8 [00425] 77% 1-9 [00426] 68% 1-10 [00427] 71% 1-11 [00428] 71% 1-12 [00429] 80% 1-13 [00430] 64% 1-15 [00431] 62% 1-16 [00432] 70% 1-17 [00433] 83% 1-18 [00434] 65% 1-19 [00435] 73% 1-20 [00436] 77% 1-21 [00437] 60% 1-22 [00438] 64% 1-23 [00439] 71% 1-24 [00440] 76% 1-25 [00441] 80% 1-26 [00442] 65% 1-27 [00443] 74% 1-28 [00444] 69% 1-29 [00445] 73% 1-30 [00446] 60%

B) Device Examples

[0145] OLEDs according to the invention and OLEDs in accordance with the prior art are produced by a general process in accordance with WO2004/058911, which is adapted to the circumstances described here (layer-thickness variation, materials).

[0146] The substrates used are glass plates coated with structured ITO (indium tin oxide) in a thickness of 50 nm. The OLEDs basically have the following layer structure: substrate/hole-injection layer (HIL)/hole-transport layer (HTL)/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 OLEDs is pointed out at each experiment described below. The structures of the materials used for the production of the OLEDs are shown in Table 1.

[0147] All materials are applied by thermal vapour deposition in a vacuum chamber. The emission layer always consists of at least 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%) means 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%. A layer composition, where only the percentage of the second material is given adds up to 100% with the percentage of the first material. Analogously, the electron-transport layer may also consist of a mixture of two materials.

[0148] The OLEDs are characterised by standard methods. For this purpose, the external quantum efficiency (EQE, measured in percent) as a function of the luminous density, calculated from current/voltage/luminous 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 luminous density of 10 mA/cm.sup.2. LT80 @ 60 mA/cm.sup.2 is defined as the time until the luminance of the OLED device drops to 80% of its initial luminous intensity at a constant driving current density of 60 mA/cm.sup.2. The data obtained for the various OLEDs are summarised in the text below.

Use of Compounds According to the Invention as Hole-Transport Materials in Fluorescent OLEDs

[0149] In particular, compounds according to the invention are suitable as HIL, HTL or EBL in OLEDs. They are suitable as a single layer, but also as mixed component as HIL, HTL, EBL or within the EML. The samples comprising the compounds according to the invention exhibit both high efficiency (Table 2 and 3) and also high lifetime (Table 3).

TABLE-US-00007 TABLE 1 Structures of the materials used [00447] [00448] [00449] [00450] [00451] [00452] [00453] [00454] [00455] [00456] [00457]

Example 1

[0150] Singlet blue devices with the following structures (E1, E2, E3 and E4) were produced:

TABLE-US-00008 TABLE 2 Structure of the OLEDs and results Layer type [Thickness (nm)] E1 E2 E3 E4 HIL HIM:F4TCNQ HIM:F4TCNQ HIM:F4TCNQ HIM:F4TCNQ [20] (5%) (5%) (5%) (5%) HTL HIM HIM HIM HIM [175] EBL HTM1 HTM2 HTM3 HTM4 [20] EML H1:SEB H1:SEB H1:SEB H1:SEB [20] (5%) (5%) (5%) (5%) ETL ETM:LiQ ETM:LiQ ETM:LiQ ETM:LiQ [30] (50%)  (50%)  (50%)  (50%)  EIL LiQ LiQ LiQ LiQ [1] EQE@10 mA/ 8.3 8.9 9.0 9.3 cm.sup.2 (%)

[0151] Further singlet blue devices with the structures E5 and E6 were produced:

TABLE-US-00009 TABLE 3 Structure of the OLEDS and results Layer type [Thickness (nm)] E5 E6 HIL HTM1:F4TCNQ HTM2:F4TCNQ [20] (5%) (5%) HTL HTM1 HTM2 [180] EBL HTM HTM [10] EML H1:SEB H1:SEB [20] (5%) (5%) ETL ETM:LiQ ETM:LiQ [30] (50%)  (50%)  EIL LiQ LiQ [1] EQE @ 10 mA/cm.sup.2 (%)    7.8    8.0 LT80 @ 60 mA/cm.sup.2 (h) 360 370

[0152] All devices exhibit an operating voltage of 3.9V-4.0V at a driving current density of 10 mA/cm.sup.2.