On the π bonding in some transition-metal hexacarbonyls

Abstract

The ratios of the intensities, l of the two polarized Raman lines relative to adjacent solvent emissions have been obtained for Cr, Mo, and W hexacarbonyls whilst attempts were made to study the ions V(CO)₆⁺ and Re(CO)₆^–. It is suggested that the ratio lν₁(A_1g)/lν₂(A_1g) is related to the π character in the M–C bonds and hence that the strength of the bonds falls in the order Re > Mo > W > Cr. The significance of the results is discussed.