TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation: No general method for preparation of compound (I) is given. Preferred Components: The organic layer comprises at least one compound selected from arylamine compounds or styrylarylamine compounds; at least one metal selected from organometals of Group 1, Group 2, 4th period and 5th period transition metals, lanthanide metals or d-transition elements in the Periodic Table of Elements; and an electroluminescent layer and charge generating layer. Preferred Components: The host compounds are selected from 4 compounds as given in the specification e.g. compound of formula (IIa) and (IIb).R101-R102=H, deuterium, 1-60C alkyl, halo, 6-60C aryl, 3-60C heteroaryl, 5- or 6-membered heterocycloalkyl containing at least one heteroatom(A1), or 3-60C cycloalkyl, (where the aryl or heteroaryl are optionally substituted by at least one G4);G4=1-60C alkyl, halo(1-60C)alkyl, 1-60C alkyloxy, 3-60C cycloalkyl, 6-60C aryl, 4-60C heteroaryl, halo, cyano, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl or tri(6-60C)arylsilyl;R103-R106=H, deuterium, 1-60C alkyl, 1-60C alkyloxy, halo, 4-60C heteroaryl, 5-60C cycloalkyl or 6-60C aryl, (where the heteroaryl, cycloalkyl or aryl are optionally substituted by at least one G5);G5=1-60C alkyl (optionally substituted by halo), 1-60C alkyloxy, 3-60C cycloalkyl, halo, cyano, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl or tri(6-60C)arylsilyl. SPECIFIC COMPOUNDS - 883 Compounds are disclosed as the compound (I) e.g. 5,6,8,Nasterisk2asterisk,Nasterisk2asterisk,Nasterisk11asterisk,Nasterisk11asterisk-heptaphenyl-triphenylene-2,11-diamine (I'), diphenyl-(5,6,8-triphenyl-triphenylen-2-yl)-amine, di-p-tolyl-(5,6,8-triphenyl-triphenylen-2-yl)-amine, di-naphthalen-2-yl-(5,6,8-triphenyl-triphenylen-2-yl)-amine, and bis-(4-fluoro-phenyl)-(5,6,8-triphenyl-triphenylen-2-yl)-amine.    EXAMPLE - A two-necked flask was charged with 7,10-dibromo-1,2,4-triphenyl-triphenylene (6 g), diphenylamine (4.1 g), tris(dibenzylideneacetone)dipalladium (0) (178 mg), tricyclohexylphosphine (109 mg), sodium tertbutoxide (3.75 g), and it was evacuated to form a vacuum, and then filled with argon gas. Toluene (180 ml) was added, and the mixture was stirred under reflux for 5 hours. After work-up 5,6,8,Nasterisk2asterisk,Nasterisk2asterisk,Nasterisk11asterisk,Nasterisk11asterisk-heptaphenyl-triphenylene-2,11-diamine (4.6 g, 60%) was obtained.