Reactions of [Et₄N]₃[Bi{Fe(CO)₄}₄] with Alkyl Halides or Dihalides: A General Method for the Synthesis of Anionic Complexes of the Type [Et₄N]₂[RBi{Fe(CO)₄}₃] and the Cyclic Complexes R₂Bi₂Fe₂(CO)₈

The reaction of [Et₄N]₃[Bi{Fe(CO)₄}₄] with alkyl halides or dihalides appears to be a general synthesis of the anionic complexes [Et₄N]₂[RBi{Fe(CO)₄}₃] or the cyclic complexes R₂Bi₂Fe₂(CO)₈. In the case of MeI, EtI, and PhCH₂Br, R₂Bi₂Fe₂(CO)₈ are obtained directly, which are proposed to result from dimerization of RBiFe(CO)₄ derived from the corresponding anionic complexes. As the reactivity of alkyl halides or dihalides decreases, the anionic compounds can be isolated and further treated with HOAc to form the cyclic complexes. This methodology offers a convenient route for the synthesis of organo derivatives of the anionic complex and the cyclic compound. These reactions proceed in high yield, are predictable, and can tolerate some functional groups such as Cl and Br.