Knowledge Bank

The infrared and laser excited Raman spectra of solutions of several substituted silane derivatives of cobalt carbonyl $(L2SiCo(CO)4)$ have been measured under grating resolution through the region $4000-33cm-1$. Depolarization ratios for the Raman bands have been measured. The observed bands have been assigned on the basis of $C3v$ symmetry for $Cl2SiCo(CO)4$ consistent with X-ray results. All observed bands for the $L=Cl,C6H5$ and $CH3$ compounds are assigned, and the principal features of the $(C6H\ast \ast )2SiCo(CO)4$ and the $(CH3)2SiCo(CO)4$ are interpreted on the basis of the approximate $C3v$ symmetry of the $C3SiCo(CO)4$ group. Localized mode vibrational calculations have been performed to evaluate the character of the vibrations involving the Si-Co stretch, and to elucidate the effect of silane substitution on the vibrational force field.