A new copolymer (RuB-PSS) of ruthenium(II)bis-(2,2 0 -bipyridine)(4-vinyl 2,2 0 -bipyridine) and styrene sulfonate was prepared which tethers the ruthenium chromophore directly to the polymer backbone. The photophysical properties of the copolymer, and its luminescence quenching by viologens, were compared with those of ruthenium (II) influence forward-and reverse-electron transfer reactions depending on the charge and hydrophobicity of the reactants. In the context of small molecule binding, we find that PSS provides a tenable model for DNA.

295ChemInform Abstract Copolymers are prepared by AIBN-initiated copolymerization of vinylpyridine and the title Ru complex. By variation of the monomer feed ratios, copolymers with a ratio of vinylpyridine:Ru of 2:1, 11:1 and 66:1 are obtained. Quaternization of the pendant vinylpyridine groups by N-ethylation with EtBr yields water-soluble polymers, which are characterized by 1H NMR, electronic, and atomic absorption spectroscopy. Fluorescence spectra and the lifetimes of the N-ethylated compounds in aqueous solution and the quenching of excited states by oxygen and methylviologen are measured. These data indicate that the excited-state properties are only slightly influenced by polymer-binding, whereas the accessibility of the excited state to quenchers is substantially reduced. Rates for photoreduction of methylviologen in the presence of N(CH2-CH2-OH)3 sensitized by the N-ethylated polymers are compared to those sensitized by tris(bipyridyl)ruthenium(II).

The rate of electron transfer from the excited state of the [Ru(bpy)3]2+-like center in N-ethylated copolymers of 4-vinylpyridine and [Ru(bpy)2(MeVbpy)]2+ to methylviologen, propylviologensulfonate, or ferric ion has been studied as a function of ionic strength (bpy = 2,2'-bipyridyl; MeVbpy = 4-methyl-4,-vinyl-2,2,-bipyridyl). The yields of Ru(III) centers and of reduced quencher have been determined directly by laser flash photolysis.

Copolymers are prepared by AIBN‐initiated copolymerization of vinylpyridine and the title Ru complex.