Possible hydride and methide transfer reactions: Reactions of Fe(CO)₄R^-(R = H, CH₃) and W(CO)₅R^- (R = H, CH₃, Cl, Br, I) with metal carbonyl cations

Reactions of metal carbonyl cations (M(CO)₆⁺, M = Mn, Re) with hydride-, methide- or halide-containing metal carbonyl anions (Fe(CO)₄R^-, R = H, Me; W(CO)₅R^-, R = H, Me, Cl, Br, I) produce products that indicate several mechanisms are operative. Reactions of the halo-tungsten complexes produce neutral, solvated tungsten complexes, W(CO)₅(CH₃CN) and W(CO)₅(CH₃CN)₂ and M(CO)₅X in a reaction that appears to be initiated by decomposition of W(CO)₅X^-. In contrast, the tungsten hydride and methide complexes react, predominantly, by transfer of the hydride or methide to a carbonyl of the cation at a much faster rate. The iron hydride and methide complexes react by iron-based nucleophilicity involving a two-electron process.