Unusual Seven Coordination of Oxovanadium(V) Oximato Complex: Synthesis and X-Ray Crystal Structure.

The new oxovanadium(V) complex, [VO(acac)(dametsc)] (1) (acac = acetylacetonate (-1), H₂dametsc = diacetylmonoxime-4-ethylthiosemicarbazone), has been prepared and characterized by studying its physicochemical properties. The X-ray crystal structure of the complex (1) has been determined and showed the presence of vanadium(V) atom in a unique heptacoordination state with distorted pentagonal bipyramidal geometry. The oximato ligand in the pentagonal plane is bonded to the central vanadium atom in dihapto (η² = N,O) manner with the formation of three membered ring, while the other three coordination sites in the plane are occupied by hydrazinic imine nitrogen, thiolate sulfur, and one of the acac oxygen atoms. The axial position sites are denned by the other acac oxygen and the trans oxo-atom. The supramolecular structure of the complex is exclusively constructed by intermolecular interactions, N-H … O and C-H…O. [ABSTRACT FROM AUTHOR]