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.-15. (canceled)

16. A compound of the formula (1), ##STR00441## where exactly one ring A, B, or C as depicted in formula (1) is present, and where the following applies to the symbols and indices used: A, B and C stand for a condensed aryl or a condensed heteroaryl group having 5 to 18 aromatic ring atoms, which may be substituted at each free position with a substituent R; E.sup.1, E.sup.2 are identically or differently on each occurrence, selected from B(R.sup.0), C(R.sup.0).sub.2, Si(R.sup.0).sub.2, CO, CNR, CC(R.sup.0).sub.2, O, S, SO, SO.sub.2, N(R.sup.0), P(R.sup.0) and P(O)R.sup.0; Ar.sup.L is 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; R, R.sup.0 stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, C(O)Ar.sup.3, P(O)(Ar.sup.3).sub.2, S(O)Ar.sup.3, S(O).sub.2Ar.sup.3, N(Ar.sup.3).sub.2, NO.sub.2, Si(R.sup.1).sub.3, B(OR.sup.1).sub.2, OSO.sub.2R.sup.1, 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.1, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by R.sup.1CCR.sup.1, CC, Si(R.sup.1).sub.2, Ge(R.sup.1).sub.2, Sn(R.sup.1).sub.2, CO, CS, CSe, P(O)(R.sup.1), SO, SO.sub.2, O, S or CONR.sup.1 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.1, or an aryloxy groups having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R.sup.1, where two adjacent substituents R and/or two adjacent substituents R.sup.0 may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R.sup.1; R.sup.1 stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, C(O)Ar.sup.3, P(O)(Ar.sup.3).sub.2, S(O)Ar.sup.3, S(O).sub.2Ar.sup.3, N(Ar.sup.3).sub.2, NO.sub.2, Si(R.sup.2).sub.3, B(OR.sup.2).sub.2, OSO.sub.2R.sup.2, 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.2, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by R.sup.2CCR.sup.2, CC, Si(R.sup.2).sub.2, Ge(R.sup.2).sub.2, Sn(R.sup.2).sub.2, CO, CS, CSe, P(O)(R.sup.2), SO, SO.sub.2, O, S or CONR.sup.2 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.2, or an aryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R.sup.2, where two adjacent substituents 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.2; R.sup.2 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.sup.3 is 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.sup.3; n is 0, 1, 2 or 3; m is on each occurrence, identically or differently, 0, 1, 2, 3 or 4; p is on each occurrence, identically or differently, 0, 1, 2 or 3; q, s are on each occurrence, identically or differently, 0 or 1; r is on each occurrence, identically or differently, 0, 1 or 2.

17. The compound according to claim 16, wherein n=0.

18. The compound according to claim 16, wherein q=1 and/or s=1.

19. The compound according to claim 16, wherein the rings A, B and C stand for a benzene, a naphthalene, a pyridine, a pyrimidine or a pyrazine ring, which may be substituted at each free position with a substituent R.

20. The compound according to claim 16, selected from compound of formulae (1A-1) to (1C-1) and (1A-2) to (1C-2), ##STR00442## ##STR00443## where the symbols and indices have the same meaning as in claim 16.

21. The compound of according to claim 16, selected from compound of formulae (1A-1-2) to (1A-1-5), (1B-1-2) to (1B-1-5), (1C-1-2) to (1C-1-5), (1A-2-2) to (1A-2-5), (1B-2-2) to (1B-2-5) and (1C-2-2) to (1C-2-5), ##STR00444## ##STR00445## ##STR00446## ##STR00447## ##STR00448## ##STR00449## ##STR00450## ##STR00451## where the symbols and indices have the same meaning as in claim 16.

22. The compound according to claim 16, wherein E.sup.1 and E.sup.2 are, identically or differently, on each occurrence, selected from C(R.sup.0).sub.2, O, S and N(R.sup.0).

23. The compound according to claim 16, wherein R.sup.0 stands on each occurrence, identically or differently, for H, D, F, CN, Si(R.sup.1).sub.3, a straight-chain alkyl groups having 1 to 10 C atoms or a branched or cyclic alkyl groups having 3 to 10 C atoms, each of which may be substituted by one or more radicals R.sup.1, where in each case one or more H atoms may be replaced by F, or an aryl or heteroaryl groups having 5 to 40 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.1, where two adjacent substituents R.sup.0 may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R.sup.1.

24. The compound according to claim 16, wherein Ar.sup.L is selected from aromatic or heteroaromatic ring systems having 5 to 14 aromatic ring atoms, which may in each case also be substituted by one or more radicals R.

25. The compound according to claim 16, wherein R stands on each occurrence, identically or differently, for H, D, 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.1, 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 systems having 5 to 24 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.1.

26. A process for the preparation of a compound according to claim 16, wherein a diarylamino group is introduced by a CN coupling reaction between a halogenated spirobifluorene or halogenated aryl spirobifluorene and a diarylamine.

27. A formulation comprising at least one compound according to claim 16 and at least one solvent.

28. A method comprising incorporating the compound according to claim 16 in an electronic device.

29. An electronic device comprising at least one compound according to claim 16, wherein the device is 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 according to claim 16 is employed as hole-transport material in a hole-transport or hole-injection or exciton-blocking or electron-blocking layer or as matrix material for fluorescent or phosphorescent emitters.

Description

EXAMPLES

A) Synthesis Examples

Example 1

Synthesis of bis-(fluorenyl-2-yl)-spiro-(7H-benzo[c]fluorene-7,9-fluoren-4-yl)-amine (1-1) and derivatives (1-2) bis (1-14)

[0093] ##STR00343##

Synthesis of 4-bromo-spiro-(7H-benzo[c]fluorene-7,9-fluorene) (Intermediate I-1)

[0094] 20.0 g (71 mmol) of 1-(2-Bromo-phenyl)-naphthalene (CAS-Nr.: 18937-27-3) was suspended in 500 mL of THF under Ar atmosphere then cooled at 78 C. 30 mL of (75 mmol/2.5 M in hexane) n-BuLi was added dropwise and the mixture was stirred for 1 h at this temperature. 18.3 g (71 mmol) of compound (II) was added portionwise at 78 C. and the mixture was stirred overnight at RT. After reaction completion, 200 mL of H.sub.2O was added. The organic phase was separated off and washed three times with 300 mL of water, dried over magnesium sulfate, filtered and subsequently evaporated to dryness. The residue was washed with 500 mL of heptane, filtered and used without further purification. The yield was 27.6 g (60 mmol), corresponding to 84% of theory. 25 g (54 mmol) of this compound was stirred vigorously under Ar atmosphere in a flask with 54.6 mL of HCl (540 mmol/36% aqueous solution) and 700 mL of acetic acid at 115 C. for 3 hr. The reaction mixture was cooled to RT and the resulting precipitate was washed with 100 mL of water and with 250 mL of EtOH for 2 hr in order to give a pale yellow powder. The yield was 15.8 g (35 mmol), corresponding to 66% of theory.

[0095] The following compounds are synthesized analogously:

TABLE-US-00005 Ex. Bromo-biphenyl Aryl-fluorenone Product Overall yield I-1 [00344] [00345] [00346] 56% [18937-27-3] [4269-17-4] I-2 [00347] [00348] [00349] 65% [18937-27-3] [2041-19-2] I-3 [00350] [00351] [00352] 51% [18937-27-3] [36804-63-4] I-4 [00353] [00354] [00355] 70% [13029-09-9] [3074-03-1] I-5 [00356] [00357] [00358] 75% [13029-09-9] [479-79-8]

Synthesis of bis-(fluorenyl-2-yl)-spiro-(7H-benzo[c]fluorene-7,9-fluoren-4-yl) (1-1)

[0096] 42 g (94 mmol) of intermediate (I-1) and 39.8 g (99 mmol) of bis-fluoren-2-yl-amine were suspended in 960 mL of toluene under Ar atmosphere. 3.8 mL (3.8 mmol) of tri-tert-butyl-phosphine was added to the flask and stirred under Ar atmosphere. 1.7 g (1.8 mmol) of Pd.sub.2(dba).sub.3 was added to the flask and stirred under Ar atmosphere then 13.6 g (141 mmol) of sodium tert-butoxide was added to the flask. The reaction mixture was stirred under reflux for 15 hr. The reaction mixture was cooled to RT, the organic phase was separated off, washed three times with 200 mL of water, dried over magnesium sulfate, filtered and subsequently evaporated to dryness. The residue was purified by column chromatography on silica gel using a mixture of DCM/heptane (1:5) and by sublimation in vacuo. The yield was 36.3 g (47.4 mmol), corresponding to 50% of theory.

[0097] The following compounds are obtained analogously:

TABLE-US-00006 Halogenated- Ex. spirobifluorene Amine Product Yield 1-1 [00359] [00360] [00361] 50% [500717-23-7] 1-2 [00362] [00363] [00364] 75% [1198395-24-2] 1-3 [00365] [00366] [00367] 55% [897671-69-1] 1-4 [00368] [00369] [00370] 70% [1372778-66-9] 1-5 [00371] [00372] [00373] 66% [1429508-81] 1-6 [00374] [00375] [00376] 65% [1644054-07-8] 1-7 [00377] [00378] [00379] 72% [1426933-82-5] 1-8 [00380] [00381] [00382] 68% [1644054-07-8] 1-9 [00383] [00384] [00385] 68% 1-10 [00386] [00387] [00388] 25% [897671-69-1] 1-11 [00389] [00390] [00391] 73% [1426933-82-5] 1-12 [00392] [00393] [00394] 50% [1354653-33-0] 1-13 [00395] [00396] [00397] 67% [1359833-89-8] 1-14 [00398] [00399] [00400] 66% [1456702-56-9]

Example 2Synthesis of Biphenyl-4-yl-(fluoren-2-yl)-spiro-(7H-benzo[c]fluorene-7,9-fluoren-4-yl)-4-phenyl-amine-(2-1) and Derivatives (2-2) to (2-4)

[0098] ##STR00401##

Synthesis of 4-chlorophenyl-spiro-(7H-benzo[c]fluorene-7,9-fluoren-4-yl (Intermediate II-1)

[0099] 30 g (67 mmol) of compound (I-1), 11.1 g (71 mmol) of 4-chlorophenyl boronic acid and 14.3 g (135 mmol) of sodium carbonate were suspended in 500 mL of EtOH, 500 mL of H.sub.2O and 200 mL of toluene and stirred under Ar atmosphere. 2.3 g (2 mmol) of tetrakis(triphenylphosphine)-palladium was added to the flask. The reaction mixture was stirred under reflux overnight. The reaction mixture was cooled to RT, the reaction mixture was quenched. The organic phase was separated, washed three times with 200 mL of water, dried over magnesium sulfate, filtered and subsequently evaporated to dryness. The residue was purified by column chromatography on silica gel using a mixture of DCM/heptane (1:10). The yield was 24.3 g (51 mmol), corresponding to 75.6% of theory.

[0100] The following compounds are obtained analogously:

TABLE-US-00007 Educt 1 Educt 2 Product Yield II-1 [00402] [00403] [00404] 76% [1679-18-1] II-2 [00405] [00406] [00407] 84% [63503-60-6] II-3 [00408] [00409] [00410] 89% [3900-89-8] II-4 [00411] [00412] [00413] 88% [3900-89-8] II-5 [00414] [00415] [00416] 85% [63503-60-6]

[0101] 10 g (22 mmol) of compound (11-1) and 8.3 g (23 mmol) of biphenyl-4-yl-2-(9,9-dimethylfluorenyl)-amine were suspended in 250 mL of toluene under Ar atmosphere. 0.90 mL (0.9 mmol) of tri-tert-butyl-phosphine was added to the flask and stirred under Ar atmosphere. 0.41 g (0.45 mmol) of Pd.sub.2(dba).sub.3 was added to the flask and stirred under Ar atmosphere then 3.22 g (33 mmol) of sodium tert-butoxide was added to the flask. The reaction mixture was stirred under reflux overnight. The reaction mixture was cooled to RT, the organic phase was separated off, washed three times with 100 mL of water, dried over magnesium sulfate, filtered and subsequently evaporated to dryness. The residue was purified by column chromatography on silica gel using a mixture of DCM/heptane (1:5). The yield was 12.9 g (16 mmol), corresponding to 72.9% of theory. The compound was sublimated in vacuo.

[0102] The following compounds are obtained analogously:

TABLE-US-00008 Educt 1 Educt 2 Product Yield 2-1 [00417] [00418] [00419] 73% [897671-69-1] 2-2 [00420] [00421] [00422] 44% [1427556-50-0] 2-3 [00423] [00424] [00425] 57% [1609484-31-2] 2-4 [00426] [00427] [00428] 50% [500717-23-7]

B) Devices Examples

[0103] OLEDs according to the invention and OLEDs in accordance with the prior art are produced by a general process in accordance with WO 2004/058911, which is adapted to the circumstances described here (layer-thickness variation, materials).

[0104] The data for various OLEDs are presented in Examples E1 to E4 below (see Tables 1 to 3). 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)/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.

[0105] The precise structure of the OLEDs is shown in table 1.

[0106] The materials required for the production of the OLEDs are shown in table 3.

[0107] All materials are evaporated by thermal vapour deposition in a vacuum cham-ber. 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 co-evaporation. 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.

[0108] The OLEDs are characterised 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/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 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.

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

[0109] In particular, 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. Compared with components from prior art (V1 and V2), the samples comprising the compounds according to the invention exhibit both higher efficiencies and also improved lifetimes in singlet blue.

TABLE-US-00009 TABLE 1 Structure of the OLEDs HTL HTL2 EBL EML EIL HIL Thickness/ Thickness/ Thickness/ Thickness/ ETL Thickness/ Ex. Thickness/nm nm nm nm nm Thickness/nm nm E1 HIM:F4TCNQ (5%) HIM HTM1:F4TCNQ HTM1 H1:SEB (5%) ETM:LiQ (50%) LiQ 20 nm 160 nm (5%) 10 nm 20 nm 30 nm 1 nm 20 nm E2 HIM:F4TCNQ (5%) HIM HTM2:F4TCNQ HTM2 H1:SEB (5%) ETM:LiQ (50%) LiQ 20 nm 160 nm (5%) 10 nm 20 nm 30 nm 1 nm 20 nm E3 HIM:F4TCNQ (5%) HIM HTM3:F4TCNQ HTM3 H1:SEB (5%) ETM:LiQ (50%) LiQ 20 nm 160 nm (5%) 10 nm 20 nm 30 nm 1 nm 20 nm E4 HIM:F4TCNQ (5%) HIM HTM4:F4TCNQ HTM4 H1:SEB (5%) ETM:LiQ (50%) LiQ 20 nm 160 nm (5%) 10 nm 20 nm 30 nm 1 nm 20 nm V1 HIM:F4TCNQ (5%) HIM HTMv1:F4TCNQ HTMv1 H1:SEB (5%) ETM:LiQ (50%) LiQ 20 nm 160 nm (5%) 10 nm 20 nm 30 nm 1 nm 20 nm V2 HIM:F4TCNQ (5%) HIM HTMv2:F4TCNQ HTMv2 H1:SEB (5%) ETM:LiQ (50%) LiQ 20 nm 160 nm (5%) 10 nm 20 nm 30 nm 1 nm 20 nm

TABLE-US-00010 TABLE 2 Data for the OLEDs EQE LT80 @ 10 mA/cm.sup.2 @ 60 mA/cm.sup.2 Ex. % [h] E1 8.0 320 E2 7.9 330 E3 7.8 310 E4 7.7 310 V1 7.2 290 V2 7.4 280

TABLE-US-00011 TABLE 3 Structures of the materials used [00429] F4TCNQ [00430] HIM [00431] H1 [00432] SEB [00433] ETM [00434] LiQ [00435] HTM1 [00436] HTM2 [00437] HTM3 [00438] HTM4 [00439] HTMv1 [00440] HTMv2

Example 1

[0110] OLED devices with the structures shown in table 1 are produced. Table 2 shows the performance data of the examples described. The device is a singlet blue device with comparison of HTM1, HTM2, HTM3, HTM4, HTMv1 and HTMv2 as material in the electron blocking layer (EBL). It can be shown, that the external quantum efficiency of the device @ 10 mA/cm.sup.2 with inventive materials is at least 0.3% or more higher than both of the comparative examples. Even in lifetime the inventive examples E1 to E4 are much better than the references. The device with HTM2 has a lifetime down to 80% of its initial brightness @ 60 mA/cm.sup.2 constant driving current density of 330 h. The two comparative examples achieve 290 h and 280 h respectively. Also the other three inventive examples do show higher lifetimes than the references with 320 h and twice 310 h.