Preparation and properties of molybdenum and tungsten dinitrogen complexes: XXXIV. Nucleophilic addition reactions of hydrazido(2 −) complexes with diphenylketene: Characterization of new acylhydrazido(2 −) complexes of molybdenum and tungsten

Abstract

Nucleophilic attack of the terminal nitrogen in the hydrazido(2 −) complexes [MCl 2(NNH 2)(PMe 2Ph) 3] ( 1; M  Mo, W) on the electron deficient carbon in diphenylketene resulted in the formation of the new acylhydrazido(2 −) complexes cis, mer-[MCl 2(NNHCOCHPh 2)(PMe 2Ph) 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) Å, β = 113.57(2)°, 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) (NNHCOCHPh 2(PMe 2Ph) 3]Cl ( 3) in high yields, which are diamagnetic both in a solid form and insolution. 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) Å, β = 92.74(5)°, Z = 4, R = 0.043 for 4903 reflections.