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)] · 2C2H5OC2H5

The preparation and characterization of the stable molybdenum cyanonitrosyl dimer, [{Mo(CN)5 (NO)}2(μ-pz)]4− with bridging pyrazine (pz), is described. The product is formed in anaerobic conditions by direct synthesis from NO and [Mo(CN)4O(pz)]2− ions as starting materials. The reaction involves unexpected oxo ligand release and NO incorporation. The dimer composition is confirmed by elemental analysis, X-ray crystal structure, ESI-MS spectra as well as UV-Vis, EPR and IR spectroscopy.