PREPARATION AND PROPERTIES OF MOLYBDENUM AND TUNGSTEN DINITROGEN COMPLEXES .34. NUCLEOPHILIC-ADDITION REACTIONS OF HYDRAZIDO(2-) COMPLEXES WITH DIPHENYLKETENE - CHARACTERIZATION OF NEW ACYLHYDRAZIDO(2-) COMPLEXES OF MOLYBDENUM AND TUNGSTEN

Nucleophilic attack of the terminal nitrogen in the hydrazido(2 -) complexes [MCl2-(NNH2)(PMe2Ph)3] (1; M = Mo, W) on the electron deficient carbon in diphenylketene resulted in the formation of the new acylhydrazido(2 - ) complexes cis,mer-[MCl2(NNHCOCHPh2)(PMe2Ph)3] (2). Complexes 2 are diamagnetic in solid form and the structure of 2 (M = W) has been determined by X-ray analysis. Crystal data: space group C2/c, a = 26.137(7), b = 13.154(6), c = 25.983(10) angstrom, beta = 113.57(2)-degrees, Z = 8, R = 0.093 for 2134 reflections. On the other hand, the NMR and EPR study has revealed that 2 in solution is to be considered as a mixture of the diamagnetic and paramagnetic species. Complexes 2 further reacted with excess pyridine (Py) to give the cationic acylhydrazido(2 - ) complexes mer-[MCl(Py)(NNHCOCHPh2)(PMe2Ph)3]Cl (3) in high yields, which are diamagnetic both in a solid form and in solution. The structure of 3 (M = W) has also been characterized by X-ray crystallography. Crystal data: space group P2(1)/a, a = 21.954(10), b = 13.784(7), c = 14.835(7) angstrom, beta = 92.74(5)-degrees, Z = 4, R = 0.043 for 4903 reflections.