Raman spectroscopic studies of substituted bipyridines, their ruthenium(II) complexes and surface-derivatized TiO₂

Abstract

Raman spectra of 2,2'-bipyridine-4,4'-dicarboxylic acid, 2,2'-bipyridine-4,4'- diethylcarboxylate, 2,2'- bipyridine-5,5'- diethyl carboxylate, ruthenium(II) tris (2,2'-bipyridine-4,4'- diethylcarboxylate) and ruthenium(II) tris (2,2'-bipyridine-5,5'-diethylcarboxylate) are reported. Vibrational assignments have been made for these spectra by analogy with the reported band assignments for 2,2'-bipyridine and ruthenium(II) tris (2,2'-bipyridine). Using these assignments and the literature data on metal-oxygen vibrational modes, assignments for the resonance Raman spectrum of surface-derivatized TiO₂ have also been made. This spectrum provides evidence for the nature of the binding between the TiO₂ surface and the ruthenium complex via oxygen bridges.