VIBRATIONAL AND ELECTRONIC SPECTRA AND BONDING IN IONIC TRANSITION METAL HEXACARBONYLS

The IR and Raman spectra of the metal hexacarbonyl ions V(CO)6- and Re(CO)6+ in solution and solid are reported. Twelve of the 13 fundamental frequencies of V(CO)6- and 11 of those of Re(CO)6+ were assigned, together with combination and overtone frequencies. Approximate CO stretching force constants were calculated. It is suggested that the charge on the metal has little effect on the strength of the metal-carbon bond in metal hexacarbonyls. The electronic spectra of V(CO)6- and Re(CO)6+ were assigned on the basis of the Gray and Beach assignment of the neutral metal hexacarbonyls. An estimate of the degree of back-bonding in these ions was obtained. © 1969.