TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises treating an acetic acid solution of substituted amino-arylthio/oxo pyridine intermediate of formula (XII) with tert-butyl nitrite to give substituted aza-dibenzothiophene compound or substituted azadibenzofuran compounds of formula (XIII) (representative of (I)). Preferred Process: (I) is treated with sulfuric acid prior to treatment with tert-butyl nitrite (when R2 is not halo). Preferred Components: The organic layer further comprises an emissive dopant comprising substituted tris (3-methyl-2-phenyl-pyridine) iridium complexes of formula (XIV).R5, R6 = H, alkyl or aryl. Preferred Definitions:    One of X1, X2 = N; and    the other X1, X2 = C;    R1 = H, alkyl, (hetero)aryl or halo;    R2 = H, alkyl, aryl or halo;    R1a, R2a, R3a, R4a = H or CH3; and    Y1 = S.    SPECIFIC COMPOUNDS - 93 Compounds (I) are specifically claimed e.g. 3-carbazol-9-yl-6-triphenylen-2-yl-benzo(4,5)thieno(2,3-c)pyridine of formula (Ia), 1,6-bis-carbazol-9-yl-benzo(4,5)thieno(2,3-c)pyridine, 1,3-bis-carbazol-9-yl-benzo(4,5)thieno(2,3-c)pyridine, 3,6-bis-carbazol-9-yl-benzo(4,5)thieno(2,3-c)pyridine and (6-carbazol-9-yl-benzo(4,5)thieno(2,3-c)pyridin-1-yl)-diphenyl-amine.    EXAMPLE - Mixture of 3-chloro-6-bromo-(1)benzothieno(2,3-c)pyridine (1.7 g), triphenylen-2-ylboronic acid (1.6 g), potassium phosphate tribasic (3.7 g), toluene (200 ml) and water (10 ml) was prepared and bubbled with nitrogen for 20 minutes. Then the tris(dibenzylideneacetone)dipalladium (53 mg) and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (96 mg) were added. The mixture was bubbled with nitrogen for another 20 minutes. After refluxed overnight under nitrogen, then reaction mixture was cooled and worked up to give 3-chloro-6-(2-triphenylenyl)-(1)benzothieno(2,3-c)pyridine as yellow solid. The mixture of 3-chloro-6-(2-triphenylenyl)-(1)benzothieno(2,3-c)pyridine (1.6 g), carbazole (0.72 g), palladium(II) acetate (20 mg), sodium tert-butoxide (1 g) and xylene (300 ml) was prepared and bubbled with nitrogen for 15 minutes. Then tert-butyl-phosphine (1 M solution in toluene, 0.27 ml) was added and the mixture was bubbled with nitrogen for another 15 minutes. After refluxed overnight, the reaction mixture was cooled and filtered through a silica gel plug, which was then washed with dichloromethane. The xylene portion was discarded. The combined dichloromethane filtrate was concentrated and the crude product was stirred in mixture of 20% dichloromethane in hexanes (100 ml) overnight. The residue was collected by filtration to give 3-carbazol-9-yl-6-triphenylen-2-yl-benzo(4,5)thieno(2,3-c)pyridine as light yellow solid (1.7 g, 80%).