REACTIONS OF ATO-N,O,O'](HEXAMETHYLPHOSPHORAMIDE)MOLYBDENUM(VI) COMPLEXES WITH SUBSTITUTED HYDRAZINES AND CHEMISTRY OF MOLYBDENUM(VI)-HYDRAZIDO COMPLEXES

The reaction of dioxo[N-(salicylidene)-2-aminophenolato-N,O,O'] (hexam ethylphosphoramide)molybdenum(VI), 4a, and its C-imine substituted der ivatives, 4b,c with different mono- and di-substituted hydrazines has been investigated. The reaction of 4a with 1,1-dimethylhydrazine leads to decomposition of the complex. When complex 4b is treated with 1,1- dimethylhydrazine an eta(1)-coordinated hydrazido(2-) molybdenum compl ex, 8a, is formed. The 2-aminophenolato-N,O ligand present in 8a origi nates from cleavage of the salicylidene ligand in 4b. The structure of 8a is determined by an X-ray crystallographic investigation. The elec tronic structure of 4b and 8a is investigated using extended Huckel ca lculations and based on the results for 4a, a mechanism for the format ion of 8a is postulated. The chemical properties of 8a are discussed o n the basis of its electronic structure. A general method for the prep aration of a series of complexes similar to 8a has been developed. A m inor product is also formed in the reaction of methylhydrazine with 4b and the possible structures of this complex are discussed; it is post ulated that the hydrazido ligand in this complex might coordinate to t he molybdenum atom in an eta(2)-fashion. The chemical properties of th e eta(1)-coordinated hydrazido(2-) molybdenum complex, 8a, have been i nvestigated and reactions with e.g. hydrogen chloride, dimethyl sulfat e, benzaldehyde and benzoyl chloride have been performed.