TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preparation: No preparation method is given. Preferred Components: The emitting layer comprises (I) as host material in combination with a phosphorescent emitter. Preferred Definitions:    (A1a)o-(A2a)p-(A3a)q- (A4a)r-R16 = e.g. 4b,9,10-triaza-indeno(1,2-a)inden-9-yl, 3-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-phenyl, 8-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-dibenzofuran-2-yl, 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, 3-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-benzo(4,5)furo(2,3-b)pyridin-8-yl, and 6-(4b,9,10-triaza-indeno(1,2-a)inden-9-yl)-dibenzofuran-2-yl.    SPECIFIC COMPOUNDS - 277 Compounds (I) are specifically claimed e.g. 9-(3,5-bis-benzo(4,5)furo(2,3-c)pyridin-6-yl-phenyl)-9H-4b,9,10-triaza-indeno(1,2-a)indene of formula (Ia), 10-(3-(4-(3-(1,8,10-triazatetracyclo(7.7.0.0(2,7).0(11,16))hexadeca-2(7),3,5,9,11(16),12,14-heptaen-8-yl)phenyl)-8-oxa-6-azatricyclo(7.4.0.0(2,7))trideca-1(9),2(7),3,5,10,12-hexaen-12-yl)phenyl)-1,8,10-triazatetracyclo(7.7.0.0(2,7).0(11,16))hexadeca-2(7),3,5,8,11(16),12,14-heptaene, 8-(4-(1,8,10-triazatetracyclo(7.7.0.0(2,7).0(11,16))hexadeca-2,4,6,9,11(16),12,14-heptaen-8-yl)-8-oxa-6-azatricyclo(7.4.0.0(2,7))trideca-1(9),2(7),3,5,10,12-hexaen-12-yl)-1,8,10-triazatetracyclo(7.7.0.0(2,7).0(11,16))hexadeca-2,4,6,9,11(16),12,14-heptaene, 9-(3-(3-carbazol-9-yl-phenyl)-benzo(4,5)furo(2,3-b)pyridin-6-yl)-9H-4b,9,10-triaza-indeno(1,2-a)indene, and 9-(6-(3-carbazol-9-yl-phenyl)-benzo(4,5)furo(2,3-b)pyridin-3-yl)-9H-4b,9,10-triaza-indeno(1,2-a)indene.    EXAMPLE - Mixture of 401.4 mg of 9-(3,5-bis-(4,4,5,5-tetramethyl-(1,3,2)dioxaborolan-2-yl)-phenyl)-9H-4b,9,10-triaza-indeno(1,2-a)indene and 465.1 mg of 6-bromo-benzo(4,5)furo(2,3-c)pyridine was evacuated and flushed with argon 3 times. 6 ml Tetrahydrofuran was added. 955.2 mg potassium phosphate and 25 ml of water were bubbled with argon for 25 minutes in a separate flask. 13.1 mg Tris tert-butylphosphonium tetrafluoroborate and 20.6 mg of tris(dibenzylideneacetone)dipalladium(0) were added to the reaction mixture of the starting materials in tetrahydrofuran, bubbled with argon for 3 minutes and then heated to 50 degrees C. Potassium phosphate solution was added in one portion with a syringe and the reaction mixture was heated at a bath temperature of 75 degrees C for 4 hours. The reaction mixture was cooled to room temperature and 20 ml of water were added. Tetrahydrofuran was evaporated, the reaction mixture was filtered, the residue washed with water and methanol and dried. The crude product is stirred in 100 ml of chloroform for 30 minutes, filtered and washed with chloroform. The filtrate was evaporated and then stirred in 8 ml of hot chloroform, filtered, the residue washed with chloroform and dried to obtain 407.6 mg of 9-(3,5-bis-benzo(4,5)furo(2,3-c)pyridin-6-yl-phenyl)-9H-4b,9,10-triaza-indeno(1,2-a)indene (yield 88%).