Syntheses, molecular structures, and dynamic solution behavior of nitrido (oxo) molybdenum(VI) siloxides

摘要: Abstract Cocondensation reaction of MoO 3 with hexamethyldisilazane, followed by work-ups produced the nitrido molybdenum(VI) compounds, [MoN(OSiMe ) (NH )] 2 ( 1 ), (py)] and a very unusual μ -oxo-μ -nitrido tetranuclear compound, [Mo N O(OSiMe 4 (py) ] ·2py ). When is reacted excess methanol it results in another oxonitrido Mo(VI) Mo O (OH) 8 (H O)(MeOH) The compounds were characterized elemental analyses, FT-IR, H 13 C NMR, mass spectrometry, single-crystal X-ray diffraction for . Compound dimeric solid state two bridging siloxo groups; however, toluene solution at ambient temperature, dimer readily dissociates into monomer. molecular geometry changes rapidly via pseudorotation process as deduced from variable temperature NMR study. However, lowered, monomer↔dimer equilibrium attained. Δ G ≠ 13.1 kcal mol −1 association 9.9 also fluxional, but remains monomeric down to 190 K. 12.2 In contrast, not fluxional solution. Instead, slowly disproportionated and, presumably, an pyridine adduct.