Materials for organic electroluminescent devices

Abstract

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

Claims

1. A compound of formula (1) ##STR00493## where the symbols used are as follows: Z.sup.1 is a group of the formula (2) ##STR00494## where the dotted bonds indicate the linkage of this group to the two carbon atoms explicitly shown in formula (1); Z.sup.2 is a group of the formula (4) or (5) ##STR00495## where the dotted bonds indicate the linkage of this group to X.sup.1 in formula (1); X.sup.1 group is C and the other X.sup.1 group is N; X is the same or different at each instance and is CR or N; Y is CR or N; Z is CR or N; Ar is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R radicals; R is the same or different at each instance and is H, D, F, Cl, Br, I, N(Ar′).sub.2, N(R.sup.1).sub.2, OAr′, SAr′, CN, NO.sub.2, OR.sup.1, SR.sup.1, COOR.sup.1, C(═O)N(R.sup.1).sub.2, Si(R.sup.1).sub.3, B(OR.sup.1).sub.2, C(═O)R.sup.1, P(═O)(R.sup.1).sub.2, S(═O)R.sup.1, S(═O).sub.2R.sup.1, OSO.sub.2R.sup.1, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R.sup.1 radicals, where one or more nonadjacent CH.sub.2 groups may be replaced by Si(R.sup.1).sub.2, C═O, NR.sup.1, O, S or CONR.sup.1, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, and may be substituted in each case by one or more R.sup.1 radicals; at the same time, two R radicals together may also form a ring system; Ar′ is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R.sup.1 radicals; R.sup.1 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R.sup.2).sub.2, CN, NO.sub.2, OR.sup.2, SR.sup.2, Si(R.sup.2).sub.3, B(OR.sup.2).sub.2, C(═O)R.sup.2, P(═O)(R.sup.2).sub.2, S(═O)R.sup.2, S(═O).sub.2R.sup.2, OSO.sub.2R.sup.2, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R.sup.2 radicals, where one or more nonadjacent CH.sub.2 groups may replaced by Si(R.sup.2).sub.2, C═O, NR.sup.2, O, S or CONR.sup.2 and one or more hydrogen atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R.sup.2 radicals; at the same time, two or more R.sup.1 radicals together may form a ring system; R.sup.2 is the same or different at each instance and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical, which has 1 to 20 carbon atoms and in which one or more hydrogen atoms may also be replaced by F.

2. The compound as claimed in claim 1, wherein the group of the formula (2) is a group of the formula (2a) ##STR00496## where the symbols used have the definitions given in claim 1.

3. The compound as claimed in claim 1, of the formula (6a) or (7a) ##STR00497## where the symbols used have the definitions given in claim 1 and not more than one X in the compound including the structure Z.sup.2 is N.

4. The compound as claimed in claim 1, wherein Y═N and that Z═N.

5. The compound as claimed in claim 1, wherein Ar is the same or different at each instance and is selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, quinazoline, benzimidazole, phenanthrene, triphenylene or a combination of two or three of these groups, each of which may be substituted by one or more R radicals.

6. The compound as claimed in claim 1, wherein R is the same or different at each instance and is selected from the group consisting of H, D, F, N(Ar′).sub.2, CN, OR.sup.1, a straight-chain alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, where the alkyl or alkenyl group may in each case be substituted by one or more R.sup.1 radicals and where one or more nonadjacent CH.sub.2 groups may be replaced by O, or an aromatic or heteroaromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted in each case by one or more R.sup.1 radicals; at the same time, two R radicals together may also form a ring system.

7. A formulation comprising at least one compound as claimed in claim 1 and at least one further compound, wherein the further compound is one or more solvents and/or at least one further organic or inorganic compound.

8. An electronic device comprising the formulation as claimed in claim 7.

9. An electronic device comprising the compound as claimed in claim 1.

10. An electronic device comprising at least one compound as claimed in claim 1, wherein the electronic 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-sensitized organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, organic laser diodes and organic plasmon-emitting devices.

11. An organic electroluminescent device comprising the compound as claimed in claim 1 is used as matrix material in an emitting layer and/or in an electron transport layer and/or in a hole blocker layer and/or in a hole transport layer and/or in an exciton blocker layer.

12. The compound as claimed in claim 1, wherein R.sup.2 is the same or different at each instance and is H, D, F, CN or a hydrocarbyl radical, which has 1 to 20 carbon atoms and in which one or more hydrogen atoms may also be replaced by F.

13. The compound as claimed in claim 1, selected from the compounds of the formulae (9) to (14) ##STR00498## where the symbols have the same definitions as detailed in claim 1, and Z in the formulae (9) to (12) is CR or N.

14. The compound as claimed in claim 1, of the formulae (9a) to (14b) ##STR00499## ##STR00500## ##STR00501## where the symbols used have the definitions given in claim 1 and Z in the formulae (9a) to (14b) is CR or N.

15. The compound as claimed in claim 1, selected from the compounds of the formulae (9a-2) to (14b-2) ##STR00502## ##STR00503## ##STR00504## where the symbols used have the definitions given in claim 1.

Description

EXAMPLES

Synthesis Examples

(1) The syntheses which follow, unless stated otherwise, are conducted in dried solvents under a protective gas atmosphere. The solvents and reagents can be purchased from ALDRICH or ABCR. The numbers given for the reactants that are not commercially available are the corresponding CAS numbers.

a) 1-(4,6-Diphenyl-[1,3,5]triazin-2-yl)-1H-indole

(2) ##STR00323##

(3) 6.4 g (56 mmol) of indole is dissolved in 400 ml of dimethylformamide under a protective gas atmosphere, and 3 g (75 mmol) of NaH, 60% in mineral oil, is added. After 1 h at room temperature, a solution of 2-chloro-4,6-diphenyl-[1,3,5]triazine (17 g, 63.4 mmol, in 150 ml of dimethylformamide) is added dropwise. The reaction mixture is stirred at room temperature for 12 h, then poured onto ice and extracted three times with dichloromethane. The combined organic phases are dried over Na.sub.2SO.sub.4 and concentrated. The residue is subjected to hot extraction with toluene. Yield: 15 g (43 mmol), 80% of theory.

(4) The following compounds are prepared in an analogous manner:

(5) TABLE-US-00003 Reactant 1 Reactant 2 Product Yield  1a 72%  2a 75%  3a 0 68%  4a 69%  5a 62%  6a 0 67%  7a 71%  8a 70%  9a 0 76% 10a 65%

b) 2,3-Dichloro-1-(4,6-diphenyl-[1,3,5]triazin-2-yl)-1H-indole

(6) ##STR00354##

(7) 59 g (170.7 mmol) of 1-(4,6-diphenyl-[1,3,5]triazin-2-yl)-1H-indole is dissolved in 500 ml of diethyl ether and cooled to 0° C., 24 g (341 mmol) of thionyl chloride is added dropwise to the synthesis and the mixture is stirred at room temperature overnight. Subsequently, 1 l of sodium hydrogencarbonate solution is added gradually to the mixture, which is transferred to a separating funnel, and the organic phases are separated. The organic phase is washed with brine, dried over sodium sulfate, filtered and concentrated. The product is purified via column chromatography on silica gel with toluene/heptane (2:2). Yield: 40 g (93 mmol), 73% of theory.

(8) The following compounds are prepared in an analogous manner:

(9) TABLE-US-00004 Reactant Product Yield  1b 52%  2b 45%  3b 0 47%  4b 39%  5b 41%  6b 37%  7b 51%  8b 0 70%  9b 44% 10b 54% 11b 61% 12b 58% 13b 0 54%

c) Cyclization

(10) ##STR00381##

(11) A baked-out Schlenk flask under protective gas is charged with 2.8 g (2.5 mmol, 10 mol %) of Pd(PPh.sub.3).sub.4, 1.46 g (2.5 mmol, 10 mol %) of Xantphos, 24.3 g (75 mmol) of 052003 and 5.82 g (30 mmol, 1.2 equiv.) of 2-phenyl-1H-benzimidazole. Subsequently, 10.8 g (25 mmol) of 2,3-dichloro-1-(4,6-diphenyl-[1,3,5]triazin-2-yl)-1H-indole in 200 ml of DMF is added. The mixture is stirred at room temperature for 10 min and then heated under reflux at 140° C. for 24 h. After cooling, 10 ml of dichloromethane is added and the mixture is filtered through Celite. This is followed by concentration to dryness. The product is purified via column chromatography on silica gel with toluene/heptane (2:2). The residue is subjected to hot extraction with toluene, recrystallized from toluene/n-heptane, and finally sublimed under high vacuum. The purity is 99.9%. Yield: 9 g (15.2 mmol), 70% of theory.

(12) The following compounds are prepared in an analogous manner:

(13) TABLE-US-00005 Reactant 1 Reactant 2 Product Yield  1c 64%  2c 63%  3c 0 64%  4c 62%  5c 64%  6c 69%  7c 00 01 02 66%  8c 03 04 05 60%  9c 06 07 08 71% 10c 09 0 70% 11c 71% 12c 79% 13c 0 73% 14c 77% 15c 79% 16c 73% 17c 0 68% 18c 71% 19c 70% 20c 0 57% 21c 57% 22c 53% 23c 0 55% 24c 52% 25c 55% 26c 61% 27c 0 56% 28c 59%

d) 11-(2,6-Diphenylpyrimidin-4-yl)-6H,11H-indolo[3,2-c]isoquinolin-5-one

(14) ##STR00466##

(15) Under protective gas, 20.5 g (88 mmol) of 6H-11H-indolo[3,2-c]isoquinolin-5-one, 27.3 g (88 mmol) of 4-bromo-2,6-diphenylpyrimidine, 0.8 g (0.88 mmol) of tris(dibenzylideneacetone)dipalladium and 1.79 g (7.9 mmol) of palladium acetate are suspended in 500 ml of toluene. The reaction mixture is heated under reflux for 8 h. After cooling, the organic phase is removed, washed three times with 200 ml of water and then concentrated to dryness. The product is purified via column chromatography on silica gel with toluene/heptane (2:2). The purity is 97.0%. Yield: 30 g (64 mmol), 70% of theory.

(16) The following compound is prepared in an analogous manner:

(17) TABLE-US-00006 Reactant 1 Reactant 2 Product Yield 1d 54%

e) 5-Chloro-11-(2,6-diphenylpyrimidin-4-yl)-11H-indolo[3,2-c]-isoquinoline

(18) ##STR00470##

(19) 8.8 g (19 mmol) of 11-(2,6-diphenylpyrimidin-4-yl)-6H,11H-indolo[3,2-c]-isoquinolin-5-one is additionally charged in 6 g (29 mmol) of POCl.sub.3 and 50 ml of PCl.sub.5. The mixture is boiled under reflux for 4 h, cooled down, and 100 ml of toluene is added. Saturated NaCl is added to the mixture, and the organic phase is removed. The solvent and the PCl.sub.5 are removed under reduced pressure, and the product is recrystallized from toluene under protective gas. Yield: 8.2 g (16 mmol), 90% of theory.

(20) The following compound is prepared in an analogous manner:

(21) TABLE-US-00007 Reactant Product Yield 1e 44%

f) (2-Bromophenyl)-[11-(2,6-diphenylpyrimidin-4-yl)-11H-indolo-[3,2-c]isoquinolin-5-yl]amine

(22) ##STR00473##

(23) 38.8 g (7.9 mmol) of 5-chloro-11-(2,6-diphenylpyrimidin-4-yl)-11H-indolo-[3,2-c]isoquinoline and 7.3 g (15.8 mmol) of 2-bromophenylamine are heated under reflux in 100 ml of diglyme at 160° C. for 3 h. After cooling, the residue is filtered. Yield: 8.2 g (16 mmol), 90% of theory.

(24) The following compound is prepared in an analogous manner:

(25) TABLE-US-00008 Reactant 1 Reactant 2 Product Yield 1f 68%

g) Cyclization

(26) ##STR00477##

(27) Under protective gas, 5.3 g (8.7 mmol) of (2-bromophenyl)-[11-(2,6-diphenyl-pyrimidin-4-yl)-11H-indolo[3,2-c]isoquinolin-5-yl]amine, 1.8 g (7.9 mmol) of triphenylphosphine, 0.12 g (0.5 mmol) Pd(OAc).sub.2 and 3.6 g (26 mmol) of NaCO.sub.3 are suspended in 100 ml of toluene. The reaction mixture is heated under reflux for 8 h. After cooling, the organic phase is removed, washed three times with 200 ml of water and then concentrated to dryness. The product is purified via column chromatography on silica gel with toluene/heptane (2:2) and then sublimed under high vacuum. The purity is 99.9%. Yield: 3.7 g (6.9 mmol), 80% of theory.

(28) The following compound is prepared in an analogous manner:

(29) TABLE-US-00009 Reactant Product Yield 1g 67%

(30) Production of the OLEDs

(31) Examples I1 to I6 which follow (see Table 1) present the use of the materials of the invention in OLEDs.

(32) Pretreatment for Examples I1-I6:

(33) Glass plaques coated with structured ITO (indium tin oxide) of thickness 50 nm are treated prior to coating with an oxygen plasma, followed by an argon plasma. These plasma-treated glass plaques form the substrates to which the OLEDs are applied.

(34) The OLEDs basically have the following layer structure: substrate/hole injection layer (HIL)/hole transport layer (HTL)/electron blocker layer (EBL)/emission layer (EML)/optional hole blocker layer (HBL)/electron transport layer (ETL)/optional electron injection layer (EIL) and finally a cathode. The cathode is formed by an aluminum layer of thickness 100 nm. The exact structure of the OLEDs can be found in Table 1. The materials required for production of the OLEDs are shown in Table 2.

(35) All materials are applied by thermal vapor deposition in a vacuum chamber. In this case, the emission layer always consists of at least one matrix material (host material) and an emitting dopant (emitter) which is added to the matrix material(s) in a particular proportion by volume by co-evaporation. Details given in such a form as IC1:EG1:TER (50%:45%:5%) mean here that the material IC1 is present in the layer in a proportion by volume of 50%, EG1 in a proportion by volume of 45% and TER in a proportion by volume of 5%. Analogously, the electron transport layer may also consist of a mixture of two materials.

(36) The OLEDs are characterized in a standard manner. The electroluminescence spectra are determined at a luminance of 1000 cd/m.sup.2, and the CIE 1931 x and y color coordinates are calculated therefrom.

(37) Use of Mixtures of the Invention in OLEDs

(38) The materials of the invention can be used in the emission layer in phosphorescent red OLEDs. The inventive compounds EG1 to EG5 may be used in Examples 11 to 16 as matrix material in the emission layer. The color coordinates of the electroluminescence spectra of these OLEDs are CIEx=0.67 and CIEy=0.33. The materials are thus suitable for use in the emission layer of red OLEDs. In addition, the materials of the invention can be used successfully in the hole blocker layer (HBL). This is shown in experiment 16. Here too, the color coordinates of the spectrum of the OLED are CIEx=0.67 and CIEy=0.33.

(39) TABLE-US-00010 TABLE 1 Structure of the OLEDs HIL HTL EBL EML HBL ETL EIL Ex. thickness thickness thickness thickness thickness thickness thickness I1 HATCN SpMA1 SpMA3 IC1:EG1:TER — ST2:LiQ (50%:50%) — 5 nm 125 nm 10 nm (50%:45%:5%) 40 nm 35 nm I2 HATCN SpMA1 SpMA3 IC2:EG2:TER — ST2:LiQ (50%:50%) — 5 nm 125 nm 10 nm (50%:45%:5%) 40nm 35 nm I3 HATCN SpMA1 SpMA3 IC2:EG3:TER — ST2:LiQ (50%:50%) — 5 nm 125 nm 10 nm (50%:45%:5%) 40nm 35 nm I4 HATCN SpMA1 SpMA3 IC2:EG4:TER — ST2:LiQ (50%:50%) — 5 nm 125 nm 10 nm (50%:45%:5%) 40nm 35 nm I5 HATCN SpMA1 SpMA3 EG5:TER — ST2:LiQ (50%:50%) — 5 nm 125 nm 10 nm (95%:5%) 40 nm 35 nm I6 HATCN SpMA1 SpMA3 EG5:TER EG2 ST2:LiQ (50%:50%) — 5 nm 125 nm 10 nm (95%:5%) 40 nm 5 nm 30 nm

(40) TABLE-US-00011 TABLE 2 Structural formulae of the materials for the OLEDs 0 0