Die Reaktion von Molybdänpentachlorid mit Trichlornitromethan; die Kristallstruktur von [MoOCl3 · POCl3]2

Reaction of Molybdenum Pentachloride with Trichloronitromethane. Crystal Structure of [MoOCl₃ · POCl₃]₂ An improved method for the preparation of MoO₂Cl₂ by the reaction of MoCl₅ with CCl₃NO₂ is reported. In the presence of the solvens POCl₃, molybdenum pentachloride reacts with trichloronitromethane forming the oxonitrosyl complex Mo(NO)OCl₃ · POCl₃. In CH₂Cl₂ solution this complex is decomposed forming [MoOCl₃ · POCl₃]₂. The crystal structure was solved by X-ray methods. [MoOCl₃ · POCl₃]₂ crystallizes monoclinic in the space group P2₁/c with two dimers in the unit cell (R = 0.07, 2327 independent reflexions). The complex dimerizes by symmetric chloro bridges; the oxoligand is in terminal position. The MoO bond length of 163 pm corresponds with a Mo?O triple bond. The POCl₃ molecule is coordinated in position trans to the oxoligand. The IR spectra are reported and assigned.