Unexpected direct incorporation of NO in the Mo(IV) coordination sphere. X-ray crystal structure of (PPh₄)₄[{Mo(CN)₅(NO)}₂(μ-pz)]

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• 作者：Dariusz Matoga ; Janusz Szklarzewicz and John Fawcett
• 关键词：Molybdenum ; Cyanides ; X-ray diffraction ; Structure ; Nitric oxide ; Complexes ; Pyrazine (bridging ligand)
• 刊名：Polyhedron
• 出版年：2005
• 出版时间：2005
• 年：2005
• 卷：24
• 期：12
• 页码：1533-1539
• 全文大小：375 K

文摘

The preparation and characterization of a stable cyano {MoNO}⁴ dimer with bridging pyrazine (pz), [{Mo(CN)₅(NO)}₂(μ-pz)]⁴⁻, is described. The synthesis involves the direct incorporation of nitric oxide into the [Mo(CN)₄O(pz)]²⁻ complex and unexpected oxo ligand release. The IR monitoring of the reaction in solution indicates its very complicated mechanism with NO association and nitro ligand formation steps. The isolated diamagnetic tetraphenylphosphonium salt of the dimer is characterized by means of elemental analysis, ESI-MS, cyclic voltammetry measurements as well as IR, EPR and UV–Vis spectroscopy. The molecular structure of (PPh₄)₄[{Mo(CN)₅(NO)}₂(μ-pz)] · 2C₂H₅OC₂H₅ shows that the N–O bond [1.198(4) ] in the nitrosyl ligand is longer than in gaseous nitric oxide and the Mo–N–O group is approximately linear [Mo–N–O angle is 178.2(3)°], which is expected for species with a low {MNO} electron number.