Strukturuntersuchungen an SIVN3-Gruppierungen. IV [1-3]

N-chloralkyl-nitridochloro Complexes of Molybdenum (VI). [Cl₅MoN-R]⁻ with R = CCl₃, C₂Cl₅. Crystal Structure of (AsPh₄)₂[(MoOCl₄)₂CH₃CN] In the reaction of tetraphenyl arsonium chloride with the complexes Cl₃PO (Cl₄)-MoN R (R=CCl₃, C₂Cl₅) the POCl₃ is displaced by chloride and yields [Cl₅MoN R] ⁻. From the i.r. spectra a structure with six-coordinated molybdenum and a MoN triple bond can be deduced. By reaction with water in acetonitrile the molybdenum is reduced to Mo(V) and the nitride ligand is removed yielding (AsPh₄)₂[(MoOCl₄)₂CH₃CN]. The crystal structure of this compund was determined with X-ray diffraction data. In the tetragonal structure (space group P4/n) AsPh₄⁺ cations and two different anions were found: square pyramidal [MoOCl₄]⁻ and [MoOCl₄ · NCCH₃]⁻ in which the nitrile is bonded in trans position to the oxygen. The short Mo O distances of 165 pm indicate a strong π-bonding.