Electropolymerized Films of Macromeric Assemblies

The polymer poly[4-(2-aminoethyl)styrene], prepared by living anionic polymerization, has been derivatized by amide coupling to [Ru(II)(vbpy)(2)(4-CO(2)H-4'-CH(3)bpy)](2+) (vbpy is 4-vinyl-4'-methyl-2,2'-bipyridine; 4-CO(2)H-4'-CH(3)bpy is 4-methyl-2,2'-bipyridine-4'-carboxylic acid). The resulting "macromer" can be electropolymerized on a variety of electrode materials by reductive electropolymerization. Compared to similar films of poly[Ru(II)(vbpy)(3)](PF(6))(2): (1) the macromeric films are considerably rougher, apparently having open, local microporous structures; (2) they undergo comparable rates of intrafilm charge transfer; and (3) they have shortened metal-to-ligand charge transfer (MLCT) excited state lifetimes, apparently due to quenching by film-based trap sites. Stable films of a mixed polymer have also been prepared by sequential addition of [Ru(II)(bpy)(2)(4-CO(2)H-4'-CH(3)bpy)](2+) and then the vbpy derivative.