MONONUCLEAR CIS-DIOXOVANADIUM(V) ANIONIC COMPLEXES [VO(2)L](-)(H(2)L=[1-BASE DERIVED FROM SALICYLALDEHYDE (OR SUBSTITUTED DERIVATIVES) AND 2-AMINO-2-METHYLPROPAN-1-OL) - SYNTHESIS, STRUCTURE, SPECTROSCOPY, ELECTROCHEMISTRY AND REACTIVITY STUDIES(1] SCHIFF)

The compounds [H(3)NCMe(2)CH(2)OH][VO(2)L]{H(2)L = [1 + 1] Schiff base derived from salicylaldehyde (or substituted derivatives) and 2-amino -2-methylpropan-l-ol} have been synthesized in good yields by reaction of the Schiff base (formed in situ) and a further equivalent of the a mino alcohol with [VO(acac)(2)](Hacac = acetylacetone). The structures of three of the complexes have been solved by single-crystal X-ray st udies. All the compounds were also characterized by UV/VIS, FTIR and N MR spectroscopy and by cyclic voltammetry. The three structurally char acterized mononuclear complexes contain the cis-dioxovanadium(V) moiet y and exhibit distorted square-pyramidal geometry at vanadium which is -displaced from the equatorial plane by approximate to 0.5 Angstrom. T he crystal and molecular structures of these compounds showed extensiv e hydrogen bonding between the anionic portion of the complexes and th e counter-cations of the amino alcohol which resulted in some unusual metric features of interest to the binding of vanadium in biological s ystems. Two of the compounds showed the longest V=O distances reported so far for mononuclear cis-dioxovanadium(V) complexes. Three of the c omplexes undergo photoreduction in the solid state which is attributed to their intermolecular interactions in the crystal.