Knowledge Bank

The near-resonance and resonance Raman spectra of several organo-metallic complexes in solution and in the solid state have been measured using lasing lines of the $Kr+$ and $Ar+$ ion lasers. The complexes. $[FeII$ (bipy) and MnM^{\prime} $(CO)14$ $(M\prime =$ Fe,Os,Ru), have strong ($ϵo\sim 104$) charge-transfer bands in the visible region. The various vibrational modes are observed to be selectively enhanced, and the frequency dependence of the enhancement is correlated with the symmetry of the vibrational state, electronic states, and magnitude of the vibronic energy coupling term, in light of current theories of Resonance Raman effects, Raman intensity enhancements as large as ca 400:1 were observed, and ao. third overtone of a $\sim$ $1490cm-1$ ligand band was found. The results are used to demonstrate ways of employing resonance Raman spectroscopy to investigate the UV-visible vibronic spectra of discrete charge transfer complexes.