The chemistry of metal carbonyl anions : VII. Reduction of cyclopentadienylmetal carbonyls in hexamethylphosphoramide

The alkali metal reductions of a series of monomeric and dimeric cyclopentadienyl-substituted metal carbonyls in hexamethylphosphoramide provide principally C₅H₅V(CO)₃^2- from C₅H₅V(CO)₄, Mn(CO)₄^3- from C₅H₅Mn(CO)₃, Co(CO)₄^- from C₅H₅Co(CO)₂, and C₅H₅M(CO)_y^- from corresponding C₅H₅M(CO)_y]₂, where M = Mo, Fe and Ni for y = 3, 2 and 1, respectively. The spectral and chemical properties of many of these reduced species are described.