The lowest energy transition of [Ru(CN)
4(ppb)]
2- (ppb = dipyrido[2,3-
a:3',2'-
c]phenazine), a metal-to-ligandcharge transfer, has been probed using resonance Raman spectroscopy with excitation wavelengths (488,514, 530, and 568 nm) spanning the lowest energy absorption band centered at 522 nm. Wave packet modelingwas used to simultaneously model this lowest energy absorption band and the cross sections of the resonanceRaman bands at the series of excitation wavelengths across this absorption band. A fit to within ±20% wasobtained for the Raman cross sections, close to the experimental uncertainty which is typically 10-20%.
values of 0.1-0.4 were obtained for modes which were either localized on the ppb ligand (345-1599 cm
-1)or the CN modes (2063 and 2097 cm
-1). DFT calculations reveal that the resonance Raman bands observedare due to modes delocalized over the entire ppb ligand.