SYNTHESIS AND CHARACTERIZATION OF REDOX POLYMERS OF [M(4-VINYL-4'-METHYL-2,2'-BIPYRIDINE)3](PF6)2 (M = RU, OS)

We have prepared polymers of [M(vbpy)3(PF6)2] (M = Ru, Os) (vbpy = 4-vinyl-4'-methyl-2,2'-bipyridine) in solution via free-radical polymerization and fractionated them according to molecular weight using size exclusion chromatography. Different fractions have been characterized by electrochemical and spectroscopic means. We find that whereas for the osmium containing polymers the relative polymer size varies in proportion to the number of vinyl groups consumed during the polymerization reaction, the same is not true for the analogous ruthenium polymers. In addition, the emission energy of both the ruthenium and osmium polymers is also related to the concentration of residual vinyl groups in the polymer. Upon polymerization, there is a shift in the emission toward higher energies. Electrochemically determined diffusion coefficients are consistent with the relative size of the various fractions.