Halogenation of the Hexaphosphabenzene Complex [(Cp*Mo)(2)(μ,η(6):η(6)‐P(6))]: Snapshots on the Reaction Progress

The oxidation of [(Cp*Mo)(2)(μ,η(6):η(6)‐P(6))] (1) with halogens or halogen sources was investigated. The iodination afforded the ionic complexes [(Cp*Mo)(2)(μ,η(3):η(3)‐P(3))(μ,η(1):η(1):η(1):η(1)‐P(3)I(3))][X] (X=I(3) (−), I(−)) (2) and [(Cp*Mo)(2)(μ,η(4):η(4)‐P(4))(μ‐PI(2))][I(3)] (3), while the reaction with PBr(5) led to the complexes [(Cp*Mo)(2)(μ,η(3):η(3)‐P(3))(μ‐Br)(2)][Cp*MoBr(4)] (4) [(Cp*MoBr)(2)(μ,η(3):η(3)‐P(3))(μ,η(1)‐P(2)Br(3))] (5) and [(Cp*Mo)(2)(μ‐PBr(2))(μ‐PHBr)(μ‐Br)(2)] (6). The reaction of 1 with the far stronger oxidizing agent PCl(5) was followed via time‐ and temperature‐dependent (31)P{(1)H} NMR spectroscopy. One of the first intermediates detected at 193 K was [(Cp*Mo)(2)(μ,η(3):η(3)‐P(3))(μ‐PCl(2))(2)][PCl(6)] (8) which rearranges upon warming to [(Cp*Mo)(2)(μ‐PCl(2))(2)(μ‐Cl)(2)] (9), [(Cp*MoCl)(2)(μ,η(3):η(3)‐P(3))(μ‐PCl(2))] (10) and [(Cp*Mo)(2)(μ,η(4):η(4)‐P(4))(μ‐PCl(2))][Cp*MoCl(4)] (11), which could be isolated at room temperature. All complexes were characterized by single‐crystal X‐ray diffraction, NMR spectroscopy and their electronic structures were elucidated by DFT calculations.