Patent ID: 7576208

Claim:
A compound of formula 9 wherein R 2 , R 3 , R 7 , R 8 , R 15 , R 16 , and R 17 each independently is the same or different and each independently represents: H; an optionally substituted C 1 -C 40 carbyl or hydrocarbyl group; an optionally substituted C 1 -C 40 alkoxy group; an optionally substituted C 6 -C 40 aryloxy group; an optionally substituted C 7 -C 40 alkylaryloxy group; an optionally substituted C 2 -C 40 alkoxycarbonyl group; an optionally substituted C 7 -C 40 aryloxycarbonyl group; a cyano group (—CN); a carbamoyl group (—C(═O)NH 2 ); a haloformyl group (—C(═O)—X, wherein X represents a halogen atom); a formyl group (—C(═O)—H); an isocyano group; an isocyanate group; a thiocyanate group or a thioisocyanate group; an optionally substituted amino group; an hydroxy group; a nitro group; a CF 3 group; a halo group; or an optionally substituted silyl group; and wherein independently each pair of R 2 and R 3 , R 7 and R 8 , R 15 and R 16 , and R 16 and R 17 is optionally cross-bridged with each other to form a C 4 -C 40 saturated or unsaturated ring, which saturated or unsaturated ring is optionally interrupted by an oxygen atom, a sulphur atom or a group shown by formula: —N(R a )— (wherein R a is a hydrogen atom or a hydrocarbon group), and is optionally substituted; wherein A represents silicon or germanium, and wherein one or more of the carbon atoms of the polyacene skeleton is optionally substituted by a heteroatom which is N, P, As, O, S, Se or Te, wherein at least one pair of R 2 and R 3 , R 7 and R 8 , R 15 and R 16 , and R 16 and R 17 is cross-bridged with each other to form a C 4 -C 40 saturated or unsaturated ring that is interrupted by an oxygen atom, a sulphur atom or a group shown by formula: —N(R a )— (wherein R a is a hydrogen atom or a hydrocarbon group) and is optionally substituted.