TECHNOLOGY FOCUS - ELECTRONICS - Preferred Components: The emitting layer comprises (I) as host material in combination with a phosphorescent emitter.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation: No preparation method is given. Preferred Definitions:    B1-B8 = N, CH or CR81, CR82, CR83, CR84, CR85, CR86, CR87 or CR88;    A1-A4 = benzothiopheno(2,3-b)pyridylene, pyrido(2,3-b)indolylene, benzothiopheno(2,3-c)pyridylene, pyrido(2,3-c)indolylene, thieno(3,2-b:4,5-b9dipyridylene, thieno(3,2-b:4,5-b9dipyridylene, 9H-carbazole-3,9-diyl, 4aH-4b,9,10-triaza-indeno(1,2-a)indene-3,10-diyl, dibenzo(b,d)furan-2,8-diyl, dibenzofuran-2,6-diyl, dibenzothiophene-2,8-diyl, dibenzo(b,d)thiophene-2,6-diyl, dibenzofuran-2,4-diyl or 9H-carbazole-3,9-diyl; and    (A1 )o-(A2) p-(A3)q-(A4)rR16 = e.g. 9-(3-phenylene)-9H-4b,9,10-triaza-indeno(1,2-a)indene, 6-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-benzo(4,5)furo(2,3-b)pyridin-3-yl, 3-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-benzo(4,5)furo(2,3-b)pyridin-6-yl, 6-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-benzo(4,5)furo(2,3-c)pyridin-3-yl, 8-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-dibenzofuran-4-yl, 6-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-benzo(4,5)furo(2,3-c)pyridin-1-yl, 2-(3-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-benzo(4,5)furo(2,3-b)pyridin-8-yl, 6-(10H-4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-dibenzofuran-2-yl, 8-(10H-4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-benzo(4,5)furo(2,3-b)pyridin-3-yl or 8-(10H-4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-benzo(4,5)furo(2,3-c)pyridin-3-yl.    SPECIFIC COMPOUNDS - 392 Compounds (I) are disclosed e.g. 4-(3-(benzimidazolo(1,2-a) benzimidazol-5-yl)carbazol-9-yl)benzothiopheno(3,2-b) pyridine of formula (Ia), 10-benzo(4,5)thieno(2,3-b)pyridin-3-yl-9H-4b,9,10-triaza-indeno(1,2-a)indene, 9-benzo(4,5)thieno(2,3-b)pyridin-7-yl-9H-4b,9,10-triaza-indeno(1,2-a)indene, 9-(3-benzo(4,5)thieno(2,3-b)pyridin-7-yl-phenyl)-9H-4b,9,10-triaza-indeno(1,2-a)indene and 10-(8-benzo(4,5)thieno(2,3-b)pyridin-7-yl-dibenzofuran-2-yl)-9H-4b,9,10-triaza-indeno(1,2-a)indene.    EXAMPLE - 2.8 g 4-Iodobenzothiopheno(3,2-b)pyridine, 3.4 g 5-(9H- carbazol-3-yl)benzimidazolo(1,2-a)benzimidazole, 5.7 g potassium carbonate, 5.1 g trans-cyclohexane-1,2-diamine, 342.8 mg copper iodide and 58 ml 1,4-dioxane were mixed together under argon. The suspension was heated to 100 degrees C and stirred at this temperature for 17 hours, then cooled. To the brown suspension were added 500 ml dichloromethane and 400 ml water, the suspension was warmed slightly, stirred for 5 minutes and filtered through a sintered glass funnel into the separation funnel. The residue was washed with dichloromethane, the phases were separated and the organic phase was evaporated to get 4-(3-(benzimidazolo(1,2-a) benzimidazol-5-yl)carbazol-9-yl)benzothiopheno(3,2-b) pyridine.