Compounds for electronic devices

Abstract

The present invention relates to a compound of the formula (I), to the use of this compound in an electronic device, and to an electronic device comprising one or more compounds of the formula (I). The invention furthermore relates to the preparation of the compound of the formula (I) and to a formulation comprising one or more compounds of the formula (I).

Claims

1. A compound of a formula (I) ##STR00273## wherein A is, identically or differently on each occurrence, a group of the following formula (II) or (III) ##STR00274## wherein the dashed line emanating from the nitrogen atom represents the bond from the group A to the central benzene ring; wherein the group HetAr including the nitrogen atom shown is, identically or differently on each occurrence, a heteroaryl group having 5 to 30 aromatic ring atoms, optionally substituted by one or more radicals R.sup.2; wherein the group Ar.sup.1 is, identically or differently on each occurrence, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, optionally substituted by one or more radicals R.sup.2, and wherein the two groups Ar.sup.1 may be connected via a group Y so that a ring is formed with the nitrogen atom of the group A, wherein Y is selected from a single bond, BR.sup.2, C(R.sup.2).sub.2, Si(R.sup.2).sub.2, NR.sup.2, PR.sup.2, P(?O)R.sup.2, P(?S)R.sup.2, O, S, S?O, and S(?O).sub.2; and R.sup.1 is, identically or differently on each occurrence, CN, C(?O)R.sup.3, C(?O)OR.sup.3, C(?O)N(R.sup.3).sub.2, P(?O)(R.sup.3).sub.2, OSO.sub.2R.sup.3, S(?O)R.sup.3, S(?O).sub.2R.sup.3, or a heteroaryl group selected from pyridyl, pyrazinyl, pyridazinyl, pyrimidyl and triazinyl, each of which optionally substituted by one or more radicals R.sup.3; R.sup.2 is, identically or differently on each occurrence, H, D, F, Cl, Br, I, B(OR.sup.3).sub.2, CHO, C(?O)R.sup.3, CR.sup.3?C(R.sup.3).sub.2, CN, C(?O)OR.sup.3, C(?O)N(R.sup.3).sub.2, Si(R.sup.3).sub.3, N(R.sup.3).sub.2, NO.sub.2, P(?O)(R.sup.3).sub.2, OSO.sub.2R.sup.3, OR.sup.3, S(?O)R.sup.3, S(?O).sub.2R.sup.3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms, a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms, or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein the above-mentioned groups are optionally substituted by one or more radicals R.sup.3 and wherein one or more CH.sub.2 groups in the above-mentioned groups are optionally replaced by R.sup.3C?CR.sup.3, Si(R.sup.3).sub.2, C?O, C?S, C?NR.sup.3, C(?O)O, C(?O)NR.sup.3, NR.sup.3, P(?O)(R.sup.3), O, S, SO, or SO.sub.2, and wherein one or more H atoms in the above-mentioned groups are optionally replaced by D, F, Cl, Br, I, CN, or NO.sub.2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R.sup.3, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R.sup.3, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R.sup.3, wherein two or more radicals R.sup.2 are optionally linked to one another and optionally form a ring; R.sup.3 is, identically or differently on each occurrence, H, D, F, Cl, Br, I, B(OR.sup.4).sub.2, CHO, C(?O)R.sup.4, CR.sup.4?C(R.sup.4).sub.2, CN, C(?O)OR.sup.4, C(?O)N(R.sup.4).sub.2, Si(R.sup.4).sub.3, N(R.sup.4).sub.2, NO.sub.2, P(?O)(R.sup.4).sub.2, OSO.sub.2R.sup.4, OR.sup.4, S(?O)R.sup.4, S(?O).sub.2R.sup.4, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms, or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms, or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein the above-mentioned groups are optionally substituted by one or more radicals R.sup.4 and wherein one or more CH.sub.2 groups in the above-mentioned groups are optionally replaced by R.sup.4C?CR.sup.4, C?C, Si(R.sup.4).sub.2, C?O, C?S, C?NR.sup.4, C(?O)O, C(?O)NR.sup.4, NR.sup.4, P(?O)(R.sup.4), O, S, SO, or SO.sub.2, and wherein one or more H atoms in the above-mentioned groups are optionally replaced by D, F, Cl, Br, I, CN, or NO.sub.2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R.sup.4, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R.sup.4, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R.sup.4, wherein two or more radicals R.sup.3 are optionally linked to one another and optionally form a ring; and R.sup.4 is, identically or differently on each occurrence, H, D, F, or an aliphatic, aromatic or heteroaromatic organic radical having 1 to 20 C atoms, in which, in addition, one or more H atoms are optionally replaced by D or F; two or more substituents R.sup.4 are optionally linked to one another and optionally form a ring.

2. The compound of claim 1, wherein the groups Ar.sup.1 of group A of formula (II) are identically or differently on each occurrence, an aryl group having 6 to 10 aromatic ring atoms.

3. The compound of claim 1, wherein the group A is identically or differently on each occurrence, of the formula (II), and each of the groups Ar.sup.1 are connected via the group Y.

4. The compound of claim 1, wherein the group of the formula (II) is a group of the following formulae (II-1) to (II-11): ##STR00275## ##STR00276## ##STR00277## wherein Z is, identically or differently on each occurrence, CR.sup.2 or N; and Y is selected from a single bond, BR.sup.2, C(R.sup.2).sub.2, Si(R.sup.2).sub.2, NR.sup.2, PR.sup.2, P(?O)R.sup.2, O, S, S?O, or S(?O).sub.2.

5. The compound of claim 1, wherein the group of the formula (III) is selected from the formulae (III-1) to (III-3): ##STR00278## wherein Z is, identically or differently on each occurrence, CR.sup.2 or N.

6. The compound of claim 1, wherein Y is selected from a single bond, C(R.sup.2).sub.2, NR.sup.2, O, or S.

7. The compound of claim 3, wherein Y is selected from a single bond, C(R.sup.2).sub.2, NR.sup.2, O, or S.

8. The compound of claim 1, wherein the group R.sup.1 is CN.

9. The compound of claim 1, wherein the radicals R.sup.1 in formula (I) are selected identically.

10. The compound of claim 8, wherein the radicals R.sup.1 in formula (I) are selected identically.

11. A process for the preparation of the compound of claim 1, wherein at least one intermediate of a formula (Z) ##STR00279## is reacted with at least one arylamino compound, or at least one heterocyclic compound containing at least one NH function, and X is, identically or differently on each occurrence, any reactive group.

12. An oligomer, polymer, or dendrimer, comprising one or more compounds of claim 1, wherein bonds to the oligomer, polymer, or dendrimer, are connected at any position of the formula (I) by R.sup.1, R.sup.2, or R.sup.3.

13. A formulation comprising at least one compound of claim 1 and at least one solvent.

14. A formulation comprising at least one oligomer, polymer, or dendrimer, of claim 10 and at least one solvent.

15. An electronic device comprising at least one compound of claim 1, wherein the the electronic device is selected from an organic integrated circuit (O-IC), organic field-effect transistor (O-FET), organic thin-film transistor (O-TFT), organic light-emitting transistor (O-LET), organic solar cell (O-SC), organic optical detector, organic photoreceptor, organic field-quench device (O-FQD), light-emitting electrochemical cell (LEC), organic laser diode (O-laser), or organic electroluminescent device (OLED).

16. An electronic device comprising at least one oligomer, polymer or dendrimer, of claim 12, wherein the electronic device is selected from an organic integrated circuit (O-IC), organic field-effect transistor (O-FET), organic thin-film transistor (O-TFT), organic light-emitting transistor (O-LET), organic solar cell (O-SC), organic optical detector, organic photoreceptor, organic field-quench device (O-FQD), light-emitting electrochemical cell (LEC), organic laser diode (O-laser), or organic electroluminescent device (OLED).

17. An organic electroluminescent device, wherein the compound according to claim 1 is present as hole-transport material in a hole-transporting layer, as matrix material in an emitting layer, as electron-blocking material, or as exciton-blocking material.

18. An organic electroluminescent device, wherein the oligomer, polymer or dendrimer, of claim 12 is present as hole-transport material in a hole-transporting layer, as matrix material in an emitting layer, as electron-blocking material, or as exciton-blocking material.

19. An organic electroluminescent device, wherein the compound of claim 1 is present as matrix material in a phosphorescent emitting layer, wherein, in addition to the compound according to claim 1, at least one further matrix material is present in the phosphorescent emitting layer.

20. An organic electroluminescent device, wherein the oligomer, polymer or dendrimer, of claim 12, is present as matrix material in a phosphorescent emitting layer, wherein, in addition to the compound according to claim 1, at least one further matrix material is present in the phosphorescent emitting layer.

Description

WORKING EXAMPLES

A) Synthesis Examples

(1) The following syntheses are carried out, unless indicated otherwise, in dried solvents under a protective-gas atmosphere. The solvents and reagents can be purchased from ALDRICH or ABCR.

Example 1

2,4,6-Trimethyl-N,N,N,N,N,N-hexaphenylbenzene-1,3,5-triamine

(2) ##STR00229##

(3) 14.0 ml (14 mmol) of tris-tert-butylphosphine, 1M in toluene, 1.6 g (7 mmol) of palladium(II) acetate and then 103.0 g (1.1 mol) of sodium tert-butoxide are added successively to a solution of 85.0 g (238 mmol) of 1,3,5-tribromo-2,4,6-trimethylbenzene [608-72-0] and 161.2 g (953 mmol) of diphenylamine in 2000 ml of toluene. The reaction mixture is heated under reflux for 16 h, allowed to cool to 60? C., 20 ml of acetic acid and 250 ml of water are added, the mixture is allowed to cool to room temperature, the aqueous phase is separated off, the org. phase is washed once with 500 ml of water and once with 500 ml of sat. sodium chloride solution, and the toluene is then removed in vacuo. The residue is washed by boiling once with 1000 ml of ethanol, dried in vacuo and then recrystallised six times from DMF (about 5 ml/g). A double fractional sublimation in a high vacuum (p about 10.sup.?6 mbar, T about 290? C.) is subsequently carried out. Yield: 69.6 g (112 mmol), 47% purity according to HPLC>99.9%.

(4) The following compounds were obtained analogously, using the amines shown in the following table instead of diphenylamine:

(5) TABLE-US-00005 Ex. Amine Product Yield 2 0 56% 3 38% 4 46% 5 52% 6 27% 7 0 58% 8 55% 9 58% 10 47% 11 50% 12 0 50% 13 65% 19 57% 20 11% 21 28%

(6) The following compounds were obtained analogously, using the tribromobenzene derivatives shown in the following table instead of 1,3,5-tribromo-2,4,6-trimethylbenzene:

(7) TABLE-US-00006 Ex. Tribromide Product Yield 14 0 46% 15 52% 16 41% 17 34% 18 37%

B) Device Examples: Production and Characterisation of Organic Electroluminescent Devices

(8) Electroluminescent devices according to the invention can be produced as described in general terms, for example, in WO 2005/003253. The results for OLEDs according to the invention having different structures are compared below. The basic structure, the materials used, the degree of doping and the layer thicknesses thereof are identical for better comparability.

(9) OLEDs comprising the compounds according to the invention in accordance with Example 1, 2, 3, 4, 5, 10, 11, 13, 14, 19, 20 and 21 as hole-transport material (HTL2), or as matrix material in a mixed-matrix system, or as electron-transport material are produced in the following layer structure (device Examples D1-D15):

(10) TABLE-US-00007 Hole-injection layer (HIL) 70 nm of 2,2,7,7-tetrakis(di-para-tolyl- amino)spiro-9,9-bifluorene Hole-transport layer (HTL1) 5 nm of 1,4,5,8,9,11-hexaazatriphenylene- hexacarbonitrile Hole-transport layer (HTL2) 15 nm, see table compound according to the invention, Emission layer (EML): 40 nm see Table 1, proportions in % by host and dopant vol. Electron conductor (ETL) 40 nm of ETM1 (50% by vol.) or see table compound according to the invention and ETM2 (50% by vol.) Cathode 1 nm of ETM2, 100 nm of Al on top.

(11) Furthermore, OLEDs comprising hole-transport material HTL3 in accordance with the prior art are produced for comparison (device Examples V1-V2).

(12) The structures of the compounds used with the exception of the compounds according to the invention (see table Synthesis Examples) are depicted below for clarity.

(13) ##STR00270## ##STR00271## ##STR00272##

(14) For characterisation of the OLEDs produced, the electroluminescence spectra and the external quantum efficiency (EQE, measured in %) as a function of the luminance, calculated from current/voltage/luminance characteristic lines (IUL characteristic lines), are determined.

(15) TABLE-US-00008 TABLE 1 Device results EQE at Voltage at 1000 1000 Host/ cd/m.sup.2 cd/m.sup.2 CIE Ex. HTL2 dopant ETL [%] [V] x/y D1 Ex. 1 Host 1, 90% ETM1, 50% 15.8 8.8 0.35/ IrPPy, 10% ETM2, 50% 0.62 D2 Ex. 2 Host 1, 90% ETM1, 50% 16.0 4.3 0.35/ IrPPy, 10% ETM2, 50% 0.62 D3 Ex. 4 Host 1, 90% ETM1, 50% 16.3 4.0 0.35/ IrPPy, 10% ETM2, 50% 0.62 D4 Ex. 10 Host 1, 90% ETM1, 50% 14.2 3.8 0.35/ IrPPy, 10% ETM2, 50% 0.62 D5 Ex. 14 Host 1, 90% ETM1, 50% 13.5 8.5 0.36/ IrPPy, 10% ETM2, 50% 0.63 D6 Ex. 10 Host 1, 85% ETM1, 50% 12.1 3.4 0.68/ IrPIQ, 15% ETM2, 50% 0.31 D7 Ex. 4 Host 2, 85% ETM1, 50% 12.3 6.2 0.16/ IrBIQ, 15% ETM2, 50% 0.29 D8 Ex. 4 Host 3, 65% ETM1, 50% 13.6 5.7 0.16/ Ex. 1, 25% ETM2, 50% 0.29 IrBIQ, 10% D9 Ex. 2 Host 1, 70% ETM1, 50% 17.3 3.6 0.35/ Ex. 2, 20% ETM2, 50% 0.62 IrPPy, 10% D10 Ex. 2 Host 1, 70% ETM1, 50% 15.2 4.6 0.35/ Ex. 11, 20% ETM2, 50% 0.62 IrPPy, 10% D11 Ex. 4 Host 4, 90% ETM1, 50% 8.1 5.2 0.14/ SDB1, 10% ETM2, 50% 0.14 D12 Ex. 3 Host 4, 90% Ex. 13, 50% 7.9 5.2 0.14/ SDB1, 10% ETM2, 50% 0.14 D13 Ex. 5 Host 4, 90% Ex. 19, 50% 8.0 5.5 0.14/ SDB1, 10% ETM2, 50% 0.13 D14 Ex. 1 Host 1, 65% Ex. 20, 50% 16.8 4.4 0.35/ Ex. 11, 20% ETM2, 50% 0.63 IrPPy, 15% D15 Ex. 1 Host 2, 70% Ex. 21, 50% 17.0 4.5 0.35/ Ex. 11, 20% ETM2, 50% 0.62 IrPPy, 10% V1 HTL3 Host 2, 85% ETM1, 50% 5.7 6.3 0.16/ Comp. IrBIQ, 15% ETM2, 50% 0.31 Ex. V2 HTL3 Host 1, 90% ETM1, 50% 11.0 4.5 0.36/ Comp. IrPPy, 10% ETM2, 50% 0.62 Ex.

(16) It becomes clear from the performance data measured for device Examples D1-D15 that very good results with respect to operating voltage and power efficiency can be obtained with the compounds in accordance with the present invention, both on use as hole-transport materials (D1-D11) and also on use as matrix materials for phosphorescent emitters (D8-D10) and also on use as electron-transport material (D12-15). Examples D1-D10, D14, D15 here relate to OLEDs having a phosphorescent emitter layer, and Examples D11-D13 relate to OLEDs having a fluorescent emitter layer.

(17) The comparison with hole-transport material HTL3 in accordance with the prior art (device Examples V30 and V31) shows that, for an identical structure, better performance data are achieved with the compounds according to the invention (cf. V1 with Example D7 according to the invention and V2 with Examples D1-05 according to the invention).