ENHANCED PHOTOIONIZATION OF THE TRIS-2,2'-BIPYRIDYL RU(II) COMPLEX IN POLYELECTROLYTE SOLUTIONS

The photoionization of tris-2,2'-bipyridyl Ru(II) complexes in dilute aqueous solution (pH=9.3), yielding hydrated electrons, is enhanced by a factor of about 2.5 by polyanions such as poly(methacrylate) or poly(vinyl sulfate). Moreover, the presence of polyanions causes a drastic increase in the lifetime of the hydrated electrons. The addition of LiCl to the solution reduces the enhancement factor to about 1.6. The increase in the hydrated electron yield is attributed to binding of [Ru(bpy)(3)](2+) complexes to polyanions and the counteracting effect of Li+ ions is interpreted in terms of a partial release of polyanion-bound [Ru(bpy)(3)](2+) complexes from the polymer chains.