Reductive Dimerization of the Cyclohexadienyl Complex [Mn(CO)3(η5-C6H7)] through a Radical Pathway.

Abstract

Slow naphthalenide reduction of [Mn(η5-C6H7)(CO)3] (1) generates the transient anionic radical [Mn(η5-C6H7)(CO)3]•- (4•-), which adds as a nucleophile to 1 to form, after further reduction, [Mn(CO)3{η4-C6H7−CO−Mn(η5-C6H7)(CO)2}]2-, while fast reduction of 1 at low temperature gives [{Mn(CO)3}2(μ2-η4:η4-C6H7−C6H7)]2-, a dimer of 4•-. Both reactions suggest that formation of transient 4•- allows access to new reaction manifolds in which the cyclohexadienyl ligand of the classic complex 1 has been activated to further reactions.