TECHNOLOGY FOCUS - ELECTRONICS - Preferred Device: The active layer is a hole transport layer consisting essentially of the compound (I) or (I'); or an electroactive layer comprising a host compound comprising or consisting essentially of the compound (I) or (I') and a dopant.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The compounds (I) and (I') are selected from 14 compounds as given in the specification e.g. compounds of formulae (Ia), and (Ib). Preparation (disclosed): No general method for the preparation of the compounds (I) and (I') is given. Preferred Definitions:    Ar1 and Ar2=aryl groups having no fused rings selected from phenyl, biphenyl, terphenyl, or their deuterated derivatives (all optionally substituted by at least one substituent selected from alkyl, alkoxy, silyl, or substituent with a crosslinking group);    R1 to R5=D, or 1-10C alkyl;    a and e=0, or 4;    b, c and d=1-4.    Provided that:    (1) when a and e are 4, then R1 and R5 are D;    (2) when b is 1-4, at least one R2 is alkyl;    (3) when c is 1-4, at least one R3 is alkyl; and    (4) when d is 1-4, at least one R4 is alkyl.    SPECIFIC COMPOUNDS - 17 Compounds are specifically claimed as the compounds (I) and (I') e.g. Nasterisk4asterisk,Nasterisk4''asterisk-bis-(4-bromo-phenyl)-2',5'-dihexyl-2,2''-dimethyl-Nasterisk4asterisk,Nasterisk4''asterisk-bis-(2-methyl-biphenyl-4-yl)-(1,1';4',1'')terphenyl-4,4''-diamine of formula (Ic); 2',5'-dihexyl-Nasterisk4asterisk,Nasterisk4''asterisk-bis-(2-methyl-biphenyl-4-yl)-Nasterisk4asterisk,Nasterisk4''asterisk-diphenyl-(1,1';4',1'')terphenyl-4,4''-diamine; Nasterisk4asterisk,Nasterisk4''asterisk-bis-(4'-bromo-biphenyl-4-yl)-2',5'-dihexyl-2,2''-dimethyl-Nasterisk4asterisk,Nasterisk4''asterisk-bis-(2-methyl-biphenyl-4-yl)-(1,1';4',1'')terphenyl-4,4''-diamine; Nasterisk4asterisk,Nasterisk4''asterisk-bis-(4-bromo-phenyl)-2',5'-dihexyl-Nasterisk4asterisk,Nasterisk4''asterisk-bis-(2-methyl-biphenyl-4-yl)-(1,1';4',1'')terphenyl-4,4''-diamine; and Nasterisk4asterisk,Nasterisk4''asterisk-bis-(4'-bromo-biphenyl-4-yl)-2',5'-dihexyl-2,2''-dimethyl-Nasterisk4asterisk,Nasterisk4''asterisk-bis-(4'-propyl-biphenyl-4-yl)-(1,1';4',1'')terphenyl-4,4''-diamine.    EXAMPLE - To solution of 2',5'-dihexyl-2,2''-dimethyl-Nasterisk4asterisk,Nasterisk4''asterisk-bis-(2-methyl-biphenyl-4-yl)-(1,1';4',1'')terphenyl-4,4''-diamine (1.2 g) and 1-bromo-4-iodobenzene (1.29 g) in toluene (40 ml) was added solution of Pd2-dibenzylidene acetone (dba)3 (38 mg) and 1,1'-bis(diphenylphosphino)ferrocene (DPPF) (45 mg) in toluene (5 ml), followed by addition of NaO-tert-Bu (0.365 g) under nitrogen. The resultant mixture was stirred at 95 degrees C for 16 hours. The mixture was then filtered through short silica bed and filtrate was concentrated under reduced pressure. By column chromatography (0-10% toluene in hexane) Nasterisk4asterisk,Nasterisk4''asterisk-bis-(4-bromo-phenyl)-2',5'-dihexyl-2,2''-dimethyl-Nasterisk4asterisk,Nasterisk4''asterisk-bis-(2-methyl-biphenyl-4-yl)-(1,1';4',1'')terphenyl-4,4''-diamine (1.06 g, yield = 63%) was obtained as solid.