The kinetics for the reactions of M(CO)6 (M = Cr, Mo, W) with Me3NO were studied in the absence and the presence of PPh3. The rates are 1st-order in concns. of M(CO)6 and Me3NO, but zero order in PPh3 concentration The rates of reaction decrease in the order W > Mo ?Cr. The rate increases with increasing dielec. strength of the solvent. A mechanism is proposed which involves attack on a carbonyl C with the formation of coordinatively unsatd. intermediates of the type M(CO)5, which then rapidly react with an entering ligand. Compared with other nucleophiles reported to react by CO attack in M(CO)6 substrates, Me3NO is a strong nucleophile.

Key words: REACTION MECHANISM, REACTION KINETICS, CARBONYL COMPLEX, MOLYBDENUM COMPLEX, METAL COMPLEX, OXYGEN ATOM, REACTION RATE, TRANSFER REACTIONS, CHROMIUM COMPLEX, TUNGSTEN COMPLEX