Benzimidazo[1,2-a]Benzimidazole Derivatives for Electronic Applications

Abstract

A compound of the general formula

##STR00001##

a process for the production of the compound and its use in electronic devices, especially electroluminescent devices. Improved efficiency, stability, manufacturability, or spectral characteristics of electroluminescent devices are provided when the compound of formula I is used as host material for phosphorescent emitters in electroluminescent devices.

Claims

1. A compound of the formula ##STR00174## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are independently selected from the group consisting of H; a C.sub.1-C.sub.25 alkyl group, which can optionally be substituted by E and/or interrupted by D; a C.sub.6-C.sub.24 aryl group, which can optionally be substituted by G; and a C.sub.2-C.sub.30 heteroaryl group, which can optionally be substituted by G; X.sup.1 is a group of formula -(A.sup.1).sub.o-(A.sup.2).sub.p-(A.sup.3).sub.q-(A.sup.4).sub.rR.sup.16, o is 0 or 1, p is 0 or 1, q is 0 or 1, r is 0 or 1, A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are independently selected from the group consisting of a C.sub.6-C.sub.24 arylene group, which can optionally be substituted by G, and a C.sub.2-C.sub.30 heteroarylene group, which can optionally be substituted by G; wherein the groups A.sup.1, A.sup.2, A.sup.3 and A.sup.4 may be interrupted by a group (SiR.sup.17R.sup.18); X.sup.2 is a group of formula -(A.sup.5).sub.v-(A.sup.6).sub.s-(A.sup.7).sub.t-(A.sup.8).sub.uR.sup.15, NR.sup.10R.sup.11, or Si(R.sup.12)(R.sup.13)(R.sup.14), v is 0 or 1, s is 0 or 1, t is 0 or 1, u is 0 or 1, A.sup.5, A.sup.6, A.sup.7 and A.sup.8 are independently selected from the group consisting of a C.sub.6-C.sub.24 arylene group, which can optionally be substituted by G, and a C.sub.2-C.sub.30 heteroaryl ene group, which can optionally be substituted by G; wherein the groups A.sup.5, A.sup.6, A.sup.7 and A.sup.8 may be interrupted by a group (SiR.sup.17R.sup.18); R.sup.10 and R.sup.11 are independently selected from the group consisting of a C.sub.6-C.sub.24 aryl group, which can optionally be substituted by G; and a C.sub.2-C.sub.30 heteroaryl group, which can optionally be substituted by G; or R.sup.10 and R.sup.11 together with the nitrogen atom to which they are bonded form a heteroaromatic ring, or ring system; R.sup.12, R.sup.13 and R.sup.14 are independently selected from the group consisting of a C.sub.1-C.sub.25alkyl group, which can optionally be substituted by E and/or interrupted by D; C.sub.6-C.sub.24aryl group, which can optionally be substituted by G; and a C.sub.2-C.sub.30heteroaryl group, which can optionally be substituted by G; R.sup.15 is a C.sub.6-C.sub.24aryl group, which can optionally be substituted by G; or a C.sub.2-C.sub.30 heteroaryl group, which can optionally be substituted by G; R.sup.16 is a C.sub.6-C.sub.24aryl group, which can optionally be substituted by G; or a C.sub.2-C.sub.30 heteroaryl group, which can optionally be substituted by G; R.sup.17 and R.sup.18 are independently selected from the group consisting of a C.sub.1-C.sub.25 alkyl group, and a C.sub.6-C.sub.24aryl group, which can optionally be substituted by a C.sub.1-C.sub.25 alkyl group; D is CO, COO, S, SO, SO.sub.2, O, NR.sup.65, SiR.sup.70R.sup.71, FOR.sup.72, CR.sup.63CR.sup.64, or CC, E is OR.sup.69, SR.sup.69, NR.sup.65R.sup.66, COR.sup.68, COOR.sup.67, CONR.sup.65R.sup.66, CN, or halogen, G is E; a C.sub.1-C.sub.18 alkyl group; a C.sub.6-C.sub.24 aryl group; a C.sub.6-C.sub.24 aryl group, which is substituted by F, C.sub.1-C.sub.18 alkyl, or C.sub.1-C.sub.18 alkyl which is interrupted by O; a C.sub.2-C.sub.30 heteroaryl group; or a C.sub.2-C.sub.30 heteroaryl group, which is substituted by F, C.sub.1-C.sub.18 alkyl, or C.sub.1-C.sub.18 alkyl which is interrupted by O; R.sup.63 and R.sup.64 are independently selected from the group consisting of a C.sub.6-C.sub.18 aryl; C.sub.6-C.sub.18 aryl which is substituted by C.sub.1-C.sub.18 alkyl or C.sub.1-C.sub.18 alkoxy; C.sub.1-C.sub.18 alkyl; and C.sub.1-C.sub.18 alkyl which is interrupted by O; R.sup.65 and R.sup.66 are independently selected from the group consisting of a C.sub.6-C.sub.18 aryl group; a C.sub.6-C.sub.18 aryl which is substituted by C.sub.1-C.sub.18 alkyl or C.sub.1-C.sub.18 alkoxy; a C.sub.1-C.sub.18 alkyl group; and a C.sub.1-C.sub.18 is alkyl group, which is interrupted by O; or R.sup.65 and R.sup.66 together form a five or six membered ring, R.sup.67 is a C.sub.6-C.sub.18 aryl group; a C.sub.6-C.sub.18 aryl group, which is substituted by C.sub.1-C.sub.18 alkyl or C.sub.1-C.sub.18 alkoxy; a C.sub.1-C.sub.18 alkyl group; or a C.sub.1-C.sub.18 alkyl group, which is interrupted by O, R.sup.68 is H; a C.sub.6-C.sub.18 aryl group; a C.sub.6-C.sub.18 aryl group, which is substituted by C.sub.1-C.sub.18 alkyl or C.sub.1-C.sub.18 alkoxy; a C.sub.1-C.sub.18 alkyl group; or a C.sub.1-C.sub.18 alkyl group, which is interrupted by O, R.sup.69 is a C.sub.6-C.sub.18 aryl; a C.sub.6-C.sub.18 aryl, which is substituted by C.sub.1-C.sub.18 alkyl or C.sub.1-C.sub.18 alkoxy; a C.sub.1-C.sub.18 alkyl group; or a C.sub.1-C.sub.18 alkyl group, which is interrupted by O, R.sup.70 and R.sup.71 are independently selected from the group consisting of a C.sub.1-C.sub.18 alkyl group, a C.sub.6-C.sub.18 aryl group, and a C.sub.6-C.sub.18 aryl group, which is substituted by C.sub.1-C.sub.18 alkyl, and R.sup.72 is a C.sub.1-C.sub.18 alkyl group, a C.sub.6-C.sub.18 aryl group, or a C.sub.6-C.sub.18 aryl group, which is substituted by C.sub.1-C.sub.18 alkyl provided that X.sup.1 comprises at least one C.sub.2-C.sub.30 heteroarylene or C.sub.2-C.sub.30 heteroaryl group.

2. The compound according to claim 1, which is a compound of the formula ##STR00175## wherein X.sup.1 and X.sup.2 are as defined in claim 1.

3. The compound according to claim 1, wherein X.sup.1 is a group of the formula -A.sup.1-(A.sup.2).sub.p-(A.sup.3).sub.q-(A.sup.4).sub.rR.sup.16, or -(A.sup.1).sub.o-(A.sup.2).sub.p-(A.sup.3).sub.q-(A.sup.4).sub.rR.sup.16, o is 0 or 1, p is 0 or 1, q is 0 or 1, r is 0 or 1, A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are independently selected from the group consisting of ##STR00176## R.sup.16 is a group of the formula ##STR00177## R.sup.16 is a group of the formula ##STR00178## R.sup.21 and R.sup.21 are independently selected from the group consisting of H, a phenyl group, and a C.sub.1-C.sub.18 alkyl group; R.sup.22 and R.sup.23 are independently selected from the group consisting of H, ##STR00179## X is O, S, or NR.sup.24, and R.sup.24 is a C.sub.6-C.sub.24 aryl group, or a C.sub.2-C.sub.30 heteroaryl group, which can optionally be substituted by G, wherein G is as defined in claim 1.

4. The compound according to claim 1, wherein X.sup.1 is a group of the formula -A.sup.1-(A.sup.2).sub.p-(A.sup.3).sub.q-(A.sup.4).sub.rR.sup.16, or -(A.sup.1).sub.o-(A.sup.2).sub.p-(A.sup.3).sub.q-(A.sup.4).sub.rR.sup.16, o is 0 or 1, p is 0 or 1, q is 0 or 1, r is 0 or 1, A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are independently selected from the group consisting of ##STR00180## R.sup.16 is a group of the formula ##STR00181## R.sup.16 is a group of the formula ##STR00182## and R.sup.21 is a group of the formula ##STR00183##

5. The compound according to claim 1, wherein X.sup.1 is ##STR00184## ##STR00185## ##STR00186## ##STR00187##

6. The compound according to claim 1, wherein X.sup.2 is a group of formula -(A.sup.5).sub.v-(A.sup.6).sub.s-(A.sup.7).sub.t-(A.sup.8).sub.uR.sup.15, v is 0 or 1, s is 0 or 1, t is 0 or 1, u is 0 or 1, A.sup.5, A.sup.6, A.sup.7 and A.sup.8 are independently selected from the group consisting of ##STR00188## R.sup.15 is a group of the formula ##STR00189## R.sup.26, R.sup.27, R.sup.29 and R.sup.32 are independently selected from the group consisting of H, ##STR00190## R.sup.30 and R.sup.33 are independently selected from the group consisting of ##STR00191## and R.sup.31 is ##STR00192##

7. The compound according to claim 1, wherein X.sup.2 is a group of formula -(A.sup.5).sub.v-(A.sup.6).sub.s-(A.sup.7).sub.t-(A.sup.8).sub.uR.sup.15, v is 0 or 1, s is 0 or 1, t is 0 or l, u is 0 or 1, A.sup.5, A.sup.6, A.sup.7 and A.sup.8 are independently selected from the group consisting of ##STR00193## R.sup.15 is a group of the formula ##STR00194##

8. The compound according to claim 1, wherein X.sup.2 is ##STR00195## ##STR00196## ##STR00197## ##STR00198## ##STR00199## ##STR00200## ##STR00201## ##STR00202##

9. The compound according to claim 1, which is a following compound: TABLE-US-00006 Cpd. X.sup.1 X.sup.2 A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 A-11 A-13 A-15 A-16 A-17 A-18 A-19 A-20 A-21 A-22 A-23 A-25 A-26 A-27 A-28 A-30 A-32 A-33 A-34 A-35 A-36 A-37 A-38 A-39 A-40 A-41 A-42 A-44

10. An electronic device, comprising a compound according to claim 1.

11. The electronic device according to claim 10, which is an electroluminescent device.

12. A hole transport layer, an electron/exciton blocking layer, or an emitting layer comprising a compound according to any claim 1.

13. An emitting layer, comprising a compound according to claim 1 as host material in combination with a phosphorescent emitter.

14. An apparatus selected from the group consisting of a stationary visual display unit; a mobile visual display unit; an illumination unit; a keyboard; an item of clothing; furniture; and wallpaper, comprising the electronic device according to claim 10.

15. An electrophotographic photoreceptor, a photoelectric converter, an organic solar cell a switching element an organic light emitting field effect transistor, an image sensor, a dye laser and an electroluminescent device, comprising the compound of formula I according to claim 1.

16.-17. (canceled)

18. The compound according to claim 1, wherein R.sup.16 is a C.sub.2-C.sub.30 heteroaryl group, which can optionally be substituted by G.

19. The compound according to claim 1, wherein at least one of A.sup.1, A.sup.2, A.sup.3 and A.sup.4 is a C.sub.2-C.sub.30 heteroarylene group, which can optionally be substituted by G.

Description

EXAMPLES

Example 1

[0246] ##STR00136##

[0247] a) A mixture of 5.00 g (24.1 mmol) 6H-benzimidazolo[1,2-a]benzimidazole, 6.56 g (26.5 mmol) 2-bromodibenzofuran, 5.00 g (36.2 mmol) potassium carbonate and 920 mg (4.8 mmol) copper (I) iodide in 50 ml 1-methyl-2-pyrrolidon (NMP) are stirred under argon at 200 C. for 24 h. The reaction mixture is cooled to 20 C. and 100 ml dichloromethane are added. The reaction mixture is filtered on silica gel with dichloromethane. The organic phase is washed with water and is dried with magnesium sulfate. The solvent is distilled off. The product is decocted with methyl ethyl ketone (MEK) and filtered off. (yield: 2.50 g (28%)).

[0248] .sup.1H NMR (400 MHz, DMSO-d6): 8.67 (s, 1H), 8.22-8.20 (m, 3H), 8.01 (s, 2H), 7.80 (d, J=8.3 Hz, 1H), 7.59-7.65 (m, 3H), 7.40-7.50 (m, 3H), 7.28-7.37 (m, 2H). MS (APCI(pos), m/z): 374 (M.sup.+1).

##STR00137##

[0249] b) 3.00 g (8.03 mmol) 5-dibenzofuran-2-ylbenzimidazolo[1,2-a]benzimidazole is dissolved at 50 C. under argon in 15 ml DMF. 2.14 g (12.1 mmol) N-Bromosuccinimide is added. The reaction mixture is stirred under argon at 50 C. for 18 h. The precipitated product is filtered off and is washed with DMF, ethanol, water and again ethanol (yield: 2.85 g (78%)).

[0250] .sup.1H NMR (400 MHz, THF-d8): 8.56 (d, J=2.1 Hz, 1H), 8.23 (d, J=1.9 Hz, 1H), 8.10-8.14 (m, 2H), 7.98 (dd, J=2.3 Hz, J=8.7 Hz, 1H), 7.83 (d, L=8.7 Hz, 1H), 7.64-7.70 (m, 2H), 7.51-7.56 (m, 2H), 7.36-7.43 (m, 4H).

##STR00138##

[0251] c) 1.50 g (3.32 mmol) 2-bromo-5-dibenzofuran-2-yl-benzimidazolo[1,2-a]benzimidazole, PGP-132 3 1,50 g (1.59 mmol) 4,4,5,5-tetramethyl-2-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1,3,2-dioxaborolane, 4.02 g (16.6 mmol) potassium phosphate tribasic monohydrate, 15 ml dioxane, 50 ml xylene and 10 ml water are degassed with argon. 82 mg (0.20 mmol) 2-dicyclohexylphosphino-2,6-dimethoxybiphenyl (sPhos) and 7.4 mg (0.033 mmol) palladium(II) acetate are added. The reaction mixture is degassed with argon and is stirred for 22 h at 100 C. under argon. 40 ml of a 1% sodium cyanide solution are added and the reaction mixture is refluxed for 1 h, cooled to 20 C. and the product is filtered off. The product is washed with water and ethanol and decocted in MEK (yield: 1.05 g (38.5%)).

[0252] .sup.1H NMR (400 MHz, TFA-d1): 8.54 (s, 2H), 8.41 (d, J=2.3 Hz, 2H), 8.37 (d, J=8.0 Hz, 2H) 8.07-8.19 (m, 6H), 7.92-7.95 (m, 4H), 7.68-7.88 (m, 14H), 7.54 (t, J=7.5 Hz, 2H). MS (APCI(pos), m/z): 821 (M.sup.+1).

Example 2

[0253] ##STR00139##

[0254] a) 19.7 g (96.5 mmol) iodo-benzene, 31.4 g (96.5 mmol) caesium carbonate, 2.30 g (12.1 mmol) copper(I) iodide and 2.78 g (24.1 mmol) L-proline are added to 10.0 g (48.3 mmol) 5H-benzimidazo[1,2-a]benzimidazole in 150 ml DMSO under nitrogen. The reaction mixture is stirred for 26 h at 120 C. and is filtered on Hyflo with toluene. The organic phase is washed with water and is dried with magnesium sulfate. The solvent is removed in vacuum. The product is filtered on silica gel with toluene and is decocted with diethyl ether (yield: 7.77 g (57%)).

[0255] .sup.1H NMR (400 MHz, CDCl.sub.3): 7.81-7.88 (m, 5H), 7.57-7.67 (m, 2H), 7.45-7.50 (m, 1H), 7.31-7.40 (m. 4H)

##STR00140##

[0256] b) The reaction is carried out according to example 1 b).

[0257] .sup.1H NMR (400 MHz, CDCl.sub.3): 8.02 (d, J=1.7 Hz, 1H), 7.83-7.87 (m, 3H), 7.64-7.73 (m, 3H), 7.58-7.61 (m, 1H), 7.39-7.53 (m, 4H)

##STR00141##

[0258] c) 1.50 g (4.14 mmol) 2-bromo-5-phenyl-benzimidazolo[1,2-a]benzimidazole, 5.02 g (20.7 mmol) potassium phosphate tribasic monohydrate, 15 ml dioxane, 50 ml toluene and 12 ml water are added to 2.23 g (4.56 mmol) 9-[8-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)dibenzofuran-2-yl]carbazole. The mixture is degassed with argon. 100 mg (0.250 mmol) 2-dicyclohexylphosphino-2,6-dimethoxybiphenyl (SPhos) and 93 mg (0.042 mmol) palladium(II) acetate are added. The reaction mixture is degassed with argon and is stirred for 21 h at 100 C. under argon. 40 ml of a 1% sodium cyanide solution are added and the reaction mixture is refluxed for 1 h. The organic phase is separated and the crystallized product is filtered off, washed with ethanol, water and ethanol. The product is crystallized from toluene (yield 1.52 g (60%)).

[0259] .sup.1H NMR (400 MHz, THF-d8): =8.53 (d, J=1.7 Hz, 1H), 8.40 (d, J=1.7 Hz, 1H), 8.37 (s, 1H), 8.20 (s, 1H), 8.17 (s, 1H), 8.11-8.14 (m, 1H), 7.98-8.03 (m, 3H), 7.90 (d, J=8.5 Hz, 1H), 7.78 (d, J=8.6 Hz, 1H), 7.67-7.73 (m, 4H), 7.60-7.64 (m, 2H), 7.33-7.44 (m, 4H), 7.33-7.37 (m, 2H), 7.24-7.28 (m, 2H) MS (APCI(pos), m/z): 615 (M.sup.+1).

Example 3

[0260] ##STR00142##

[0261] a) 7.78 g (25 mmol) 1-bromo-3-iodo-benzene, 16.3 g (50.0 mmol) caesium carbonate, 1.24 g (6.50 mmol) copper(I) iodide and 1.50 g (13.0 mmol) L-proline are added to 5.18 g (25.0 mmol) mmol) 5H-benzimidazo[1,2-a]benzimidazole in 100 ml dimethylsulfoxide (DMSO) under nitrogen. The reaction mixture is stirred for 18 h at 100 C. and poured into water. The organic phase is extracted with dichloromethane and dried with magnesium sulfate. The solvent is distilled off. Column chromatography on silica gel with toluene gives the product (yield 8.35 g (92%)).

[0262] .sup.1H NMR (400 MHz, CDCl.sub.3): 8.54 (d, J=2.1 Hz, 1H), 8.37-8.40 (m, 1H), 8.16-8.199 (m, 1H), 7.93-7.95 (m, 1H), 7.60-7.74 (m, 4H), 7.41-7.7.50 (m, 3H).

[0263] MS (APCI(pos), m/z): 444 (M.sup.+1), 442 (M.sup.+1), 441 (M.sup.+1).

##STR00143##

[0264] b) The reaction is carried out according to example 1 b) except that 5-(3-bromophenyl)benzimidazolo[1,2-a]benzimidazole is used as starting material instead of 5-dibenzofuran-2-ylbenzimidazolo[1,2-a]benzimidazole.

[0265] .sup.1H NMR (400 MHz, CDCl.sub.3): 8.54 (d, J=2.1 Hz, 1H), 8.37-8.40 (m, 1H), 8.16-8.199 (m, 1H), 7.93-7.95 (m, 1H), 7.60-7.74 (m, 4H), 7.41-7.7.50 (m, 3H).

[0266] MS (APCI(pos), m/z): 444 (M.sup.+1), 442 (M.sup.+1), 441 (M.sup.+1).

Example 4

[0267] ##STR00144##

[0268] a) 1.00 g (3.53 mmol) 5-phenylbenzimidazolo[1,2-a]benzimidazole (example 2a) and 850 mg (2.65 mmol) diacetoxy-iodobenzene in 10 mt acetic acid and 10 ml acetic acid anhydride are heated to 60 C. and then cooled to 25 C. 340 mg (1.34 mmol) iodine are added. 10 drops of sulfuric acid are added and the reaction mixture is stirred under nitrogen at 25 C. for 18 h. The product is filtered off and is washed with acetic acid, ethanol, water and again ethanol. The product is decocted with methyl ethyl ketone (yield: 560 mg (40%)).

[0269] .sup.1H NMR (400 MHz, THF-d8): 5=8.39 (d, J=1.6 Hz, 1H), 8.11-8.14 (m, 1H), 7.97-8.00 (m, 2H), 7.61-7.71 (m, 4H), 7.37-7.48 (m, 4H).

[0270] MS (APCI(pos), m/z): 444 (M.sup.+1), 442 (M.sup.+1), 441 (M.sup.+1).

##STR00145##

[0271] b) 750 mg (2.01 mmol) 2-iodo-5-phenyl-benzimidazolo[1,2-a]benzimidazole, 1.31 g (4.02 mmol) caesium carbonate, 77 mg (0.40 mmol) copper(I) iodide and 93 mg (0.80 mmol) L-proline are added to 460 mg (221 mmol) carbazole in 10 ml dimethylsulfoxide (DMSO) under nitrogen. The reaction mixture is stirred for 23 h at 120G under nitrogen, poured into water and the product is filtered off. Column chromatography on silica gel with toluene, than toluene/ethyl acetate results in the product.

[0272] .sup.1H NMR (400 MHz, THF-d8): =8.30 (d, J=2.0 Hz, 1H), 8.21 (d, J=7.8 Hz, 2H), 8.03-8.11 (m, 3H), 7.90 (d, J=8.5 Hz, 1H), 7.67-7.91 (m, 3H), 7.47-7.55 (m, 2H), 7.33-7.42 (m, 6H), 7.25-7.29 (m, 2H).

Example 5

[0273] ##STR00146##

[0274] The synthesis of 9-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)carbazole is described in WO2012/023947A1. 1.30 g (2.87 mmol) 2-bromo-5-dibenzofuran-2-ylbenzimidazolo[1,2-a]benzimidazole (example 1c)), 3.21 g (14.4 mmol) potassium phosphate tribasic monohydrate, 15 ml dioxane, 50 ml toluene and 10 ml water are added to 1.48 g (3.45 mmol) 9-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)carbazole. The mixture is degassed with argon. 71 mg (0.17 mmol) 2-dicyclohexylphosphino-2,6-dimethoxybiphenyl (SPhos) and 65 mg (0.029 mmol) palladium(II) acetate are added. The reaction mixture is degassed with argon and is stirred for 6 h at 100 C. under argon. 40 ml of a 1% sodium cyanide solution are added and the reaction mixture is refluxed for 1 h. The water phase is extracted with dichloromethane and washed with 20% HCl. The organic phase is dried with magnesium sulfate and the solvent is distilled off. Column chromatography on silica gel with toluene gives the product MS (APCI(pos), m/z): 615 (M.sup.+1).

Example 6

[0275] ##STR00147##

[0276] a) 5.00 g (17.7 mmol) 5-phenylbenzimidazolo[1,2-a]benzimidazole, 5.12 g (15.9 mmol) (diacetoxyido)benzene and 4.03 g (15.9 mmol) Iodine are stirred at 25 C. for 28 h. The reaction mixture is poured into a 10% sodium hydrosulfite solution. The product is filtered off, washed with water and ethanol, decocted with diethyl ether, filtered off, washed with ether and decocted with methyl ethyl ketone (MEK) (yield: 5.67 g (87%)).

##STR00148##

[0277] b) 5.00 g (12.2 mmol) 2-iodo-5-phenyl-benzimidazolo[1,2-a]benzimidazole, 2.25 g (13.4 mmol) carbazole, 2.53 g (18.3 mmol) potassium carbonate and 470 mg (2.44 mmol) copper iodide in 150 ml NMP are stirred under nitrogen at 200 C. for 25 h. The solvent is distilled off. Dichloromethane is added and the organic phase is washed with water, 30% NaOH, water and a 1M solution of 1 amino-1-propanol in water. The organic phase is dried with magnesium sulfate and is filtered on silica gel. Column chromatography on silica gel with toluene/ethyl acetate 100/1 gives the product (yield: 4.21 g (77%)).

[0278] .sup.1H NMR (400 MHz, THF-d8): =8.30 (d, J=2.0 Hz, 1H), 8.21 (d, J=7.8 Hz, 2H), 8.03-8.11 (m, 3H), 7.90 (d, J=8.5 Hz, 1H), 7.67-7.91 (m, 3H), 7.47-7.55 (m, 2H), 7.33-7.42 (m, 6H), 7.25-7.29 (m, 2H).

Example 7

[0279] ##STR00149##

[0280] a) 76.9 g (0.460 mol) carbazole and 104 g (0.460 mol) 1-iodopyrrolidine-2,5-dione (NiS) in 100 m ml acetic acid are stirred under nitrogen at 20 C. After 5 h the product is filtered off. The product is crystalized from 900 mt ethanol using 2 g charcoal. The ethanol solution is filtered hot. The ethanol solution is cooled to 20 C. and the product is filtered off (yield: 59.5 g (44%)).

##STR00150##

[0281] b) 19.7 g (67.0 mmol) 3-iodo-9H-carbazole and 2.95 g (73.7 mmol) sodium hydride 60% dispersion in mineral oil in 500 ml tetrahydrofuran (THF) is stirred at 50 C. under nitrogen for 1 h. 12.8 g (67.0 mmol) 4-methylbenzenesulfonyl chloride in 100 ml THF are added at 20 C. The reaction mixture is stirred for 1 h at 20 C. and is then stirred for 1 h at 50 C. The solution is filtered and the solvent is distilled off. 200 ml ethyl acetate are added and the organic phase is washed with a solution of citric acid, sodium hydrogen carbonate and water. The solvent is partly removed until the product starts to crystalize. The product is filtered off and washed with methanol (yield: 23 g (79%)).

##STR00151##

[0282] c) 36.0 g (174 mmol) 6H-benzimidazolo[1,2-a]benzimidazole, 77.8 (174 mmol) 3-iodo-9-(p-tolylsulfonyl) carbazole, 106 g (0.500 mol) potassium phosphate, 5.5 g (28.9 mmol) copper iodide, and 111 g (0.972 mol) trans-cyclohexane-1,2-diamine in 900 ml dioxane are stirred at 100 C. 48 h under nitrogen. The product is filtered off, washed with dioxane, and ethanol and is used without purification in the next reaction step.

##STR00152##

[0283] d) A solution of 11.3 g (202 mmol) potassium hydroxide in 500 ml ethanol is added under nitrogen within 5 minutes to 53 g (101 mmol) 5-[9-(p-tolylsulfonyl)carbazol-3-yl]benzimidazolo[1,2-a]benzimidazole in 500 ml boiling ethanol. After 5 h the product is filtered off and is washed with ethanol, water and methanol (yield: 32 g (85.4%)). .sup.1H NMR (400 MHz, DMSO-d6): 11.6 (s, 1H), 8.57 (d, J=7.8 Hz, 1H), 8.22-8.28 (m, 3H), 7.74-7.82 (m, 2H), 7.57-7.62 (m, 2H), 7.38-7.54 (m, 4H), 7.27-7.34 (m, 2H), 7.20-7.24 (m, 1H).

##STR00153##

[0284] e) 480 mg (1.29 mmol) 5-(9H-carbazol-3-yl)benzimidazolo[1,2-a]benzimidazole, 530 mg (1.29 mmol) 2-iodo-5-phenyl-benzimidazolo[1,2-a]benzimidazole, 100 mg (0.525 mmol) copper iodide, 1.06 g (5.00 mmol) potassium phosphate and 1.00 g (8.76 mmol) transcyclohexane-1.2-diamine in 10 ml dioxane are refluxed under nitrogen for 6 h. The product is filtered off and is washed with dioxane and then methanol (yield: 440 mg (52%)). .sup.1H NMR (400 MHz, CDCl.sub.3): 8.54 (d, J=1.9 Hz, 1H), 8.23 (d, J=7.8 Hz, 1H), 8.02-8.07 (m, 2H), 7.88-7.93 (m, 4H), 7.80-7.85 (m, 3H), 7.48-7.72 (m, 9H), 7.31-7.43 (m, 7H)

Example 8

[0285] ##STR00154##

[0286] 1.00 g (2.44 mmol) 2-iodo-5-phenyl-benzimidazolo[1,2-a]benzimidazole, 610 mg (2.93 mmol) 6H-benzimidazolo[1,2-a]benzimidazole, 93 mg (0.49 mmol) copper iodide, 1.59 g (4.489 mmol) caesium carbonate and 113 mg (0.98 mmol) L-proline in 10 ml DMSO are stirred at 150 C. under nitrogen for 43 h. The reaction mixture is poured into water and the product is filtered off. The product is washed with water. Column chromatography on silica gel with toluene/ethyl acetate 19/1 ant than 1/1 gives the product (yield: 220 mg (18%)). .sup.1H NMR (400 MHz, THF-d8): 8.59 (d, J=1.8 Hz, 1H), 8.06-8.13 (m, 1H), 8.00-8.06 (m, 4H), 7.81-7.87 (m, 1H), 7.75-7.81 (m, 1H), 7.72-7.74 (m, 1H), 7.50-7.69 (m, 4H), 7.43-7.49 (m, 1H), 7.31-7.42 (m, 4H), 7.24-7.30 (m, 2H). MS (APCI(pos), m/z): 489 (M.sup.+1).

Example 9

[0287] ##STR00155##

[0288] 1.00 g (2.76 mmol) 2-bromo-5-phenyl-benzimidazolo[1,2-a]benzimidazole, 1.15 g (3.31 mmol) 2-dibenzofuran-4-yl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 1.91 g (13.8 mmol) potassium carbonate, 10 ml dioxane, 30 ml xylene and 7 ml water are degassed with argon. 23 mg (0.055 mmol) 2-dicyclohexylphosphino-2,6-dimethoxybiphenyl (sPhos) and 6.2 mg (0.028 mmol) palladium(II) acetate are added. The reaction mixture is degassed with argon and is stirred for 21 h at 120 C. under argon. 40 ml of a 1% sodium cyanide solution are added and the reaction mixture is refluxed for 1 h. Dichloromethane is added and the organic phase is separated. The organic phase is dried with magnesium sulfate and the solvent is distilled off. The product is decocted in toluene, filtered off and washed with toluene (yield: 0.91 g (73%)). 1H NMR (400 MHz, CDCl.sub.3): 8.45 (d, J=1.0 Hz, 1H), 8.04-8.07 (m, 1H), 7.99-8.00 (m, 6H), 7.74-7.76 (m, 1H), 7.66-7.71 (m, 3H), 7.61-7.64 (m, 1H), 7.49-7.54 (m, 3H), 7.38-7.47 (m, 3H).

Example 10

[0289] ##STR00156##

[0290] a) 4.70 g (10.8 mmol) 5-(3,5-diphenylphenyl)benzimidazolo[1,2-a]benzimidazole, 3.30 g (15.9 mmol) (diacetoxyido)benzene and 2.60 g (10.3 mmol) iodine are stirred at 25 C. for 18 h. The reaction mixture is poured into a 10% sodium hydrosulfite solution. The product is filtered off, washed with water and ethanol, decocted with t-butylmethylether, filtered off and washed with t-butylmethylether (yield: 5.64 g (98%)). 1H NMR (400 MHz, DMSO-d6): 8.62 (d, J=1.6 Hz, 1H), 8.36-8.38 (m, 1H), 8.133 (s, 1H), 8.129 (s, 1H), 8.01-8.02 (m, 1H), 7.87-7.89 (m, 4H), 7.75-7.78 (m, 1H), 7.59-7.61 (m, 1H), 7.51-7.56 (m, 4H), 7.43-7.47 (m, 5H).

##STR00157##

[0291] b) Example 6b) is repeated, except that instead of 2-iodo-5-phenyl-benzimidazolo[1,2-a]benzimidazole the product of Example 10a) is used, .sup.1H NMR (400 MHz, DMSO-d6): 8,32 (d, J=1.8 Hz, 1H), 8.29 (d, J=1.6 Hz, 2H), 8.20-8.22 (m, 2H), 8.11-8.13 (m, 1H), 8.04-8.05 (m, 1H), 7.85-7.95 (m, 6H), 7.52-7.57 (m, 5H), 7.36-7.47 (m, 8H), 7.25-7.30 (m, 2H).

Example 11

[0292] ##STR00158##

[0293] Example 6b) is repeated, except that instead of 2-dibenzofuran-4-yl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 9-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)carbazole is used, .sup.1H NMR (400 MHz, THF-d8): 8.62 (d, J=1.6 Hz, 1H), 8.40 (s, 1H), 8.31 (d, J=7.7 Hz, 1H), 8.20 (d, J=7.3 Hz, 1H), 8.05 (d, J=7.7, 2H), 7.88 (dd, J=1.6 Hz, 8.4 Hz, 1H), 7.64-7.78 (m, 9H), 7.37-7.56 (m, 7H), 7.29-7.33 (m, 1H). MS (APCI(pos), m/z): 525 (M.sup.+1).

Application Example 1

[0294] The ITO substrate used as the anode is first cleaned with an acetone/isopropanol mixture in an ultrasound bath. To eliminate any possible organic residues, the substrate is exposed to a continuous ozone flow in an ozone oven for further 25 minutes. This treatment also improves the hole injection properties of the ITO. Then Plexcore OC AJ20-1000 (commercially available from Flextronics Inc.) is spin-coated and dried to form a hole injection layer (40 nm).

[0295] Thereafter, the organic materials specified below are applied by vapor deposition to the clean substrate at a rate of approx. 0.5-5 nm/min at about 10.sup.7-10.sup.9 mbar. As a hole transport and exciton blocker,

##STR00159##

for preparation, see Ir complex (7) in the application WO2005/019373), is applied to the substrate with a thickness of nm, wherein the first 10 nm are doped with MoO.sub.x (10%) to improve the conductivity,

[0296] Subsequently, a mixture of 10% by weight of emitter compound,

##STR00160##

5% by weight of compound lr(dpbic).sub.3 and 85% by weight of compound

##STR00161##

is applied by vapor deposition in a thickness of 40 nm. Subsequently, material (A-43) is applied by vapour deposition with a thickness of 5 nm as blocker. Thereafter, a 20 nm thick electron transport layer is deposited consisting of 50% by weight of

##STR00162##

and of 50% of Liq

[0297] ##STR00163##

Finally a 2 nm KF layer serves as an electron injection layer and a 100 nm-thick Al electrode completes the device.

[0298] All fabricated parts are sealed with a glass lid and a getter in an inert nitrogen atmosphere. To characterize the OLED, electroluminescence spectra are recorded at various currents and voltages. In addition, the current-voltage characteristic is measured in combination with the light output emitted. The light output can be converted to photometric parameters by calibration with a photometer.

TABLE-US-00001 Voltage @ EQE.sup.1) @ 300 nits [V] 300 nits [%] CIE Appl. Ex. 1 6.5 V 7% 0.17 0.31 .sup.1)External quantum efficiency (EQE) is # of generated photons escaped from a substance or a device/# of electrons flowing through it.

Application Example 2

[0299] The substrate treatment is accomplished as in example 1.

[0300] Thereafter, the organic materials specified below are applied by vapor deposition to the clean substrate at a rate of approx. 0.5-5 nm/min at about 10.sup.7-10.sup.9 mbar. As a hole transport and exciton blocker,

##STR00164##

for preparation, see Ir complex (7) in the application WO2005/019373), is applied to the substrate with a thickness of 20 nm, wherein the first 10 nm are doped with MoO.sub.x (10%) to improve the conductivity.

[0301] Subsequently, a mixture of 10% by weight of emitter compound,

##STR00165##

5% by weight of compound lr(dpbic).sub.3 and 85% by weight of compound (A-43) is applied by vapor deposition in a thickness of 40 nm. Subsequently, material (A-43) is applied by vapour deposition with a thickness of 5 nm as blocker. Thereafter, a 20 nm thick electron transport layer is deposited consisting of 50% by weight of compound (C-1) and of 50% of Liq. Finally a 2 nm KF layer serves as an electron injection layer and a 100 nm-thick Al electrode completes the device.

[0302] All fabricated parts are sealed with a glass lid and a getter in an inert nitrogen atmosphere. The characterization of the device is performed as in example 1.

TABLE-US-00002 Voltage @ EQE.sup.1) @ 300 nits [V] 300 nits [%] CIE Appl. Ex. 2 4.05 V 11.2% 0.35/0.60 .sup.1)External quantum efficiency (EQE) is # of generated photons escaped from a substance or a device/# of electrons flowing through it.

Application Example 3

[0303] The sample preparation for PL measurements is performed at ambient conditions by solution processing. Therefore, 96% by weight of compound

##STR00166##

and 4% by weight of compound

##STR00167##

are dissolved in methylencloride and deposited onto a quartz substrate by doctor blading.

[0304] The PL spectrum and the PL quantum efficiency are measured using an absolute quantum-yield measurement system Quantaurus (from Hamamatsu, Japan) at room temperature at an excitation wavelength of 370 nm.

TABLE-US-00003 PLQE [%] CIE Appl. Ex. 3 76.8% 0.15/0.24

Comparative Application Example 1

[0305] The device fabrication is done as in Application Example 1 except that compound (A-43) is replaced by compound

##STR00168##

Application Example 4

[0306] The device is fabricated as in Comparative Application Example 1 except that in the emissive layer compound V-1 is replaced by compound

##STR00169##

[0307] The table below clearly demonstrates that compound A-24 leads as compared to compound V-1 to a reduced voltage and a significantly blue shifted colour at comparable quantum efficiency.

TABLE-US-00004 Voltage @ EQE.sup.1) @ Host 300 nits [V] 300 nits [%] CIE Comp. Appl. Ex. 1 V-1 5.44 13.51 0.302 Appl. Ex. 4 A-24 5.04 13.39 0.272

Application Example 5

[0308] The substrate treatment is accomplished as in Application Example 1.

[0309] Thereafter, the organic materials specified below are applied by vapor deposition to the clean substrate at a rate of approx. 0.5-5 nm/min at about 10.sup.7-10.sup.9 mbar.

[0310] First a 10 nm thick hole transport layer,

##STR00170##

is deposited onto the substrate which is doped with MoO.sub.x (10%) to improve the conductivity. Material

##STR00171##

is deposited subsequently with 10 nm thickness as a blocker.

[0311] Then, a mixture of 10% by weight of emitter compound

##STR00172##

5% by weight of compound lr(dpbic).sub.3 and 85% by weight of compound (V-1) is applied by vapor deposition in a thickness of 40 nm. Thereafter, a 20 nm thick electron transport layer is deposited consisting of 50% by weight of compound (C-1) and of 50% of Liq. Finally a 2 nm KF layer serves as an electron injection layer and a 100 nm-thick Al electrode completes the device. All fabricated parts are sealed with a glass lid and a getter in an inert nitrogen atmosphere. The characterization of the device is performed as in example 1.

Comparative Application Example 2

[0312] The device is fabricated as in Application Example 5, except that the blocker A-51 is replaced by compound

##STR00173##

[0313] As shown in the table below, compound A-51 leads due to a better hole injection to a reduced voltage as compared to compound V-2 and thus also better quantum efficiency.

TABLE-US-00005 Voltage @ EQE.sup.1) @ EBL 300 nits [V] 300 nits [%] CIE Appl. Ex. 5 A-51 7.26 9.16 0.275 Comp. Appl Ex. 2 V-2 8.05 8.10 0.276