TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation: No preparation method is given. Preferred Components: The organic layer is a hole injection layer, a hole transport layer, an electron blocking layer, an emission layer, a hole blocking layer, an electron transport layer or electron injection layer, where the emission layer further comprises a red, green or white phosphorescent or fluorescent dopant. The phosphorescent dopant comprises an organometallic compound having at least one element comprising iridium, platinum, osmium, titanium, zirconium, hafnium, europium, terbium or thulium. Preferred Definitions:    Ar1 = anthracene, naphthalene, chrysene, triphenylene, perylene, 9H-fluorene, 9,9-diphenyl-9H-fluorene, phenanthrene, benzene, biphenyl, (1,1',4',1")terphenyl, 9-phenyl anthracene, 9,10-di-naphthalen-2-yl-6-phenyl-anthracen-2-yl, 2,6-diphenyl-anthracen-9,10-diyl, 1-meta-tolyl-anthracen-1-yl (all optionally substituted);    Ar2 = phenyl, naphthalene, biphenyl or cyclohexane (all optionally substituted); and    R1-R5, X = H, 1-20C alkyl, 1-20C alkoxy, phenyl, biphenyl, pentalenyl, indenyl, naphthyl, biphenylenyl, anthracenyl, azurenyl, heptalenyl, acenaphthylenyl, phenalenyl, fluorenyl, methylanthryl, phenanthrenyl, triphenylenyl, pyrenyl, chrysenyl, ethyl-chrysenyl, picenyl, perylenyl, chloroperylenyl, pentaphenyl, pentacenyl, tetraphenylenyl, hexaphenyl, hexacenyl, rubicenyl, coronenyl, trinaphthylenyl, heptaphenyl, heptacenyl, fluorenyl, pyranthrenyl, ovalenyl, carbazolyl, thiophenyl, indolyl, purinyl, benzimidazolyl, quinolinyl, benzothiophenyl, parathiazinyl, pyrrolyl, pyrazolyl, imidazolyl, imidazolinyl, oxazolyl, thiazolyl, triazolyl, tetrazolyl, oxadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, thianthrenyl, cyclopentyl, cyclohexyl, oxiranyl, pyrrolidinyl, pyrazolidinyl, imidazolyl, piperidinyl, piperazinyl, morpholinyl, di(6-50C aryl)amino group or tri(6-50C aryl)silyl group.    SPECIFIC COMPOUNDS - 1 Compound (I) is disclosed i.e. 6-(3-(10-naphthalen-2-yl-anthracen-9-yl)-phenyl)-2,3-diphenyl-benzo(b)thiophene of formula (Ia).    EXAMPLE - 6-Bromo-2,3-diphenyl-benzo(b)thiophene (B1) (3 g) was dissolved in tetrahydrofuran (70 ml). Separately, 4,4,5,5-tetramethyl-2-(4-(10-naphthalen-2-yl-anthracen-9-yl)-phenyl)-(1,3,2)dioxaborolane (4.99 g), tetrakis(triphenylphoshpine)palladium(0) (470 mg) and potassium carbonate (0.82 mmol) were dissolved in toluene (30 ml) and water (8.4 ml) and then added to the obtained (B1) solution. The resultant solution was stirred for 24 hours at a reflux temperature, cooled to room temperature, and then diethyl ether (100 ml) was added to it. The mixture was worked up to give 6-(3-(10-naphthalen-2-yl-anthracen-9-yl)-phenyl)-2,3-diphenyl-benzo(b)thiophene (63%).