Diffusion and reactivity of ruthenium (II) tris(bipyridine) and cobalt (II) tris(bipyridine) in organically modified silicates

The diffusivity and reactivity of Ru(bpy)(3)(2+) and Co(bpy)(3)(2+) trapped within organically modified silicate (ORMOSIL) monoliths have been studied using electrogenerated chemiluminescence, voltammetry, and amperometry. For gel-encapsulated Ru(bpy)(3)(2+)-tripropylamine, the shape and intensity of the luminescence-voltage curve was highly dependent on the amount of organoalkoxysilane introduced into the matrix. Likewise, for gel-encapsulated Co(bpy)(3)(2+), the magnitude of the diffusion coefficient and its rate of change with drying was also dependent on the organic modifier in the gel. A comparison of the results to those obtained with the gels prepared solely from tetramethoxysilane revealed enhanced diffusivity and reactivity of the reagents encapsulated in the ORMOSIL matrix.