Halogenation and oxygenation of the metal and oxidation of phosphorus in complexes of the type M(dppe)2(N2)2 (M=Mo, W) by reaction with thionylhalides

M(dppe)2(N2)2 (M=Mo, W; dppe=1,2-bis(diphenylphosphino)ethane) is converted by thionylchloride into the chlorinated and oxygenated derivatives MoCl4(dppeO2) and WCl3(O)(dppeO2), respectively. In contrast, thionylbromide reacts with W(dppe)2(N2)2, to give specifically the tetrabromide WBr4(dppe). The molecular structure of MoCl4(dppeO2) has been determined by single crystal X-ray analysis.