Multiphoton, multielectron transfer photochemistry in a soluble polymer

The effects of laser irradiance and quencher concentration on photochemical electron transfer in a Ru-II-bpy derivatized, polystyrene polymer have bee n studied. The polymer was a 1:1 copolymer of styrene:p-chloromethylstyrene with, on the average, similar to 30 repeat units in which each of the chlo ro groups was replaced by a [Ru-II(bpy)(2)(4-CH2O-4'-CH(3)bpy)](2+) chromop hore by nucleophilic substitution. The abbreviation for the resulting polym er salt is [co-PS-CH2OCH2-(Ru-30(II))](PF6)(60). Upon visible excitation by laser flash photolysis at high irradiances, multiphoton excitation in the presence of high concentrations of the reductive quencher phenothiazine lea ds to individual polymeric strands that are reduced, on the average, by up to seven electrons to give PS-CH2OCH2- (Ru2+ Ru-23(7)+)](53+).