Reactions of octacarbonyldicobalt with some ditertiary phosphines and arsines

Abstract

Octacarbonyldicobalt reacts with ditertiary phosphines and arsines (L–L) to give [(L–L)Co(CO)₂]₂ or [(L–L)Co₂(CO)₆] complexes via the ionic intermediates [(L–L)₃Co₂(CO)₄][Co(CO)₄] and [(L–L)Co(CO)₃][Co(CO)₄] respectively. The route adopted depends on (L–L). The i.r. spectra of all compounds between 1700 and 2100 cm^–l are reported, and structures proposed which, for the covalent complexes, are based on the two tautomers of Co₂(CO)₈. The isomer obtained with the carbonyl-bridged [(Me₂As[CH₂]_nAsMe₂)Co₂(CO)₆] derivatives depends on n.