Halogenation of Diphosphorus Complexes

A systematic study of diverse halogenation reactions of the tetrahedral Mo2P2 ligand complex [{CpMo­(CO)2}2(μ,η2:η2-P2)] (1) is reported. By reacting 1 with different halogenating agents, a series of complexes such as [(CpMo)4(μ4-P)­(μ3-PI)2(μ-I)­(I)3(I3)] (2), [{CpMo­(CO)2}2(μ-PBr2)2] (3a), [{CpMo­(CO)2}­(CpMoBr2)­(μ-PBr2)2] (4a), [{CpMo­(CO)2}2(μ-PCl2)2] (3b), and [{CpMo­(CO)2}­(CpMoCl2)­(μ-PCl2)2] (4b) were obtained. Whereas the reaction of 1 toward various bromine and chlorine sources leads to similar results, a different behavior is observed in the reaction with iodine in which 2 is formed. The products were comprehensively characterized by spectroscopic methods and single crystal X-ray diffraction, and the electronic structures of 2, 3a, and 4a were elucidated by DFT calculations.