SOLVENT EFFECTS ON MOLECULAR AND IONIC SPECTRA-IX - THE CHANGE IN DIPOLE-MOMENT ACCOMPANYING METAL TO LIGAND CHARGE-TRANSFER ABSORPTION IN PENTAAMINOPYRIDYLRUTHENIUM(II)

We have previously modeled solvent effects on the metal to ligand char ge transfer (MLCT) spectra of Ru2+-(NH3)(5)-pyrazine, Ru2+(NH3)(5)-pyr azine-H+, and Ru2+(NH3)(5)-pyridine and predicted the change Delta mu in dipole moment on excitation of Ru2+(NH3)(5)-pyrazine and Ru2+(NH3)( 5)-pyrazine-H+. Prompted by a recent observation of Delta mu for Ru2+( NH3)(5)-pyridine by electroabsorption spectroscopy, we review the resu lts of our previous simulations and evaluate Delta mu. The agreement f ound between the observed and a priori calculated values is not as clo se as found for the other complexes but, given the difficulties involv ed in both the theory and experiment, is very encouraging.