Reactions of anionic transition metal carbonyl hydrides with electrophilic metal carbonyls: Nucleophilic addition (hydride transfer) vs. electron transfer mechanisms

Abstract

The relative reactivity of anionic transition metal carbonyl hydrides towards hydride transfer to monomeric metal carbonyls is consistent with an ionic route, generating, in the best-matched cases of electrophilic carbonyls (highest f CO or average v(CO)) and most nucleophilic hydrides (such as HW(CO) 4P(OMe) 3 −), metal formyls as sole product. With the metal carbonyl dimers Co 2(CO) 8, [(η 5-C 5H 5)M(CO) 3] 2 (M = Mo, W), and Mn 2(CO) 10 reductive cleavage to the respective anions occurs at rates which correlate with the nucleophilicity of the metal hydride, without observation of intermediate formyls. No reaction occurs with Re 2(CO) 10 or [(η 5-C 5H 5)Fe(CO) 2] 2.