MECHANISM OF CARBON MONOXIDE SUBSTITUTION IN METAL CARBONYL RADICALS: VANADIUM HEXACARBONYL AND ITS PHOSPHINE-SUBSTITUTED DERIVATIVES.

Article abstract of DOI:10.1021/ja00313a016

Carbon monoxide substitution in the metal radical V(CO)//6 proceeds at or below room temperature to form monosubstitution products V(CO)//5L (L equals phosphine or phosphite). The substitution occurs solely by a second-order process according to a rate law that is first order in both V(CO)//6 and phosphorus nucleophile. The rate of reaction is strongly dependent on the basicity and size of the ligand. The carbon monoxide substitution reactions of V(CO)//5L with additional L also proceed by an associative mechanism with the rate of substitution approximately three orders of magnitude slower than for V(CO)//6.