FLUORIDE-ASSISTED STABILIZATION OF AMINO-ACID COMPLEXES OF VANADIUM -SYNTHESIS AND CHARACTERIZATION

Fluoride amino acid complexes of vanadium(IV) of the type A[VOF(2)L(H2 O)] (A = Na or NH4, L = cysteinate) and A[VOF(3)L(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 elec tronic spectral studies. The vibrational spectra of the complexes indi cate coordination of the amino acids through their carboxylate group t o the metal centre. Also, the sulphydryl functionality provides an add itional coordination site in cysteine-containing complexes. Fluoride a ppears to act as a stabilising ligand which helps in the solid-stare i solation of the complexes.