Synthesis of novel polysiloxanes containing charge transporting and second-order nonlinear optical functionalities with atom economical constructs

Novel, highly functionalized polysiloxanes were prepared in which each repeat unit bears, on average, one charge transporting and one to two second-order nonlinear optical chromophores. Covalent attachment of charge-transporting carbazole or diphenylamine derivatives was realized through efficient Pt-catalyzed hydrosilylation. Poly(hydrogen methylsiloxane) was reacted with 9-(2-propenyl)carbazole or (N-phenyl-N-2-propenylamino)benzene, affording poly[methyl-3-(9-carbazolyl)propylsiloxane] and poly[methyl-3-(N,N-diphenylamino)propylsiloxane], respectively. Rather remarkable regiospecific bromination of the two arylamine-containing siloxane polymers was achieved using benzyltrimethylammonium chlorobromate, resulting in the formation of poly[methyl-3-(N-(3,6-dibromocarbazolyl))propylsiloxane] and poly[methyl-3-(N,N-bis(4-bromophenyl)amino)propylsiloxane]. Pd-catalyzed Heck-type coupling of the arylbromide-bearing polysiloxanes with either vinylbenzenephosphonic acid diethyl ester or 4-nitrostyrene afforded stilbene-containing polymers bearing phosphonate ester or nitro moieties as electron-withdrawing functionalities, respectively. These fully functionalized polymers were readily soluble in several common organic solvents.