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.