A theoretical examination of the solvent dependence of the metal-to-ligand charge-transfer band in amino ruthenium complexes

An examination is made of the electronic spectroscopy of the title complexes modeled in several solvents with ab initio and semiempirical quantum chemical techniques, generating structures by using a mixed quantum/classical (QM/MM) model, We obtain near-quantitative predictions of the spectra of these complexes, but the calculations indicate that considerable electron transfer is involved between the more polar solvents, as water, and the complex, and that accounting for this transfer is important in the prediction of the location of metal-to-ligand charge-transfer bands.