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,η6:η6-P6)] (1) with halogens or halogen sources was investigated. The iodination afforded the ionic complexes [(Cp*Mo)2(μ,η3:η3-P3)(μ,η1:η1:η1:η1-P3I3)][X] (X=I3−, I−) (2) and [(Cp*Mo)2(μ,η4:η4-P4)(μ-PI2)][I3] (3), while the reaction with PBr5 led to the complexes [(Cp*Mo)2(μ,η3:η3-P3)(μ-Br)2][Cp*MoBr4] (4) [(Cp*MoBr)2(μ,η3:η3-P3)(μ,η1-P2Br3)] (5) and [(Cp*Mo)2(μ-PBr2)(μ-PHBr)(μ-Br)2] (6). The reaction of 1 with the far stronger oxidizing agent PCl5 was followed via time- and temperature-dependent 31P{1H} NMR spectroscopy. One of the first intermediates detected at 193 K was [(Cp*Mo)2(μ,η3:η3-P3)(μ-PCl2)2][PCl6] (8) which rearranges upon warming to [(Cp*Mo)2(μ-PCl2)2(μ-Cl)2] (9), [(Cp*MoCl)2(μ,η3:η3-P3)(μ-PCl2)] (10) and [(Cp*Mo)2(μ,η4:η4-P4)(μ-PCl2)][Cp*MoCl4] (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.