Fluoride-assisted stabilisation of amino acid complexes of vanadium synthesis and characterisation

Abstract

Fluoride amino acid complexes of vanadium(IV) of the type A[VOF₂L(H₂O)] (A = Naor NH₄, L = cysteinate) and A[VOF₃L(H₂O)] (A = NH₄ for L = alanine and A = Na, NH₄ or K for L = serine) have been synthesised. The compounds have been characterised by chemical analyses, chemical determination of the oxidation state of vanadium, solution electrical conductance and magnetic susceptibility measurements, ESR, IR and electronic spectral studies. The vibrational spectra of the complexes indicate coordination of the amino acids through their carboxylate group to the metal centre. Also, the sulphydryl functionality provides an additional coordination site in cysteine-containing complexes. Fluoride appears to act as a stabilising ligand which helps in the solid-state isolation of the complexes.