The reaction of diiodotriorganophosphorus compounds with dicobalt octacarbonyl; isolation of a new isomeric form of [R3PI] [CoI3(PR3)]

Article abstract of DOI:10.1016/0020-1693(95)04813-8

The novel reaction of R₃PI compounds with dicobalt octacarbonyl has been investigated and compared to previous studies involving the reaction of R₃PI₂ compounds with cobalt metal powders. The products produced from both reactions have identical stoichiometries but, surprisingly, possess different structures. Infrared and Raman spectroscopic studies and X-ray powder diffraction clearly show that the products obtained from the reaction of R₃PI₂ with Co₂(CO)₈ are a new isomeric form of [R₃PI] [CoI₃(PR₃)], compared to the products isolated from the reaction of R₃PI₂ with cobalt metal powder. Seven examples of this new isomeric form of [R₃PI] [CoI₃(PR₃)] are reported and have been characterised by elemental analysis, Raman and quantitative electronic spectroscopy and magnetic data, the latter indicating that some antiferromagnetic coupling occurs. Some general investigations into the reaction mechanism for these reactions are reported and discussed.