title: Simple general method of generating non-oxo, non-amavadine model octacoordinated vanadium(IV) complexes of some tetradentate ONNO chelating ligands from various oxovanadium(IV/V) compounds and structural characterization of one of them.
abstract: A simple general route of obtaining very stable octacoordinated non-oxovanadium(IV) complexes of the general formula VL2 (where H2L is a tetradentate ONNO donor) is presented. Six such complexes (1-6) are adequately characterized by elemental analysis, mass spectrometry, and various spectroscopic techniques. One of these compounds (1) has been structurally characterized. The molecule has crystallographic symmetry and has a dodecahedral structure existing in a tetragonal space group Pn2. The non-oxo character and VL2 stoichiometry for all of the complexes are established from analytical and mass spectrometric data. In addition, the non-oxo character is clearly indicated by the complete absence of the strong nuV=O band in the 925-1025 cm-1 region, which is a signature of all oxovanadium species. The complexes are quite stable in open air in the solid state and in solution, a phenomenon rarely observed in non-oxovanadium(IV) or bare vanadium(IV) complexes.
authors.affiliation: Department of Chemistry, University of Calcutta, University College of Science, 92 Acharya Prafulla Chandra Road, Kolkata 700 009, India.
authors.forename: Manas
authors.initials: M
authors.lastname: Sutradhar
authors.forename: Gurunath
authors.initials: G
authors.lastname: Mukherjee
authors.forename: Michael G B
authors.initials: MG
authors.lastname: Drew
authors.forename: Saktiprosad
authors.initials: S
authors.lastname: Ghosh