Electrochemical and spectroscopic study of vanadyl acetylacetonate–ionic liquids interactions

A panel of ionic liquids has been synthesized and their effect on the vanadyl acetylacetonate solubility in acetonitrile has been firstly assessed. 1-Butyl-3-methylimidazolium acetate showed an unprecedented result, increasing the VO(acac)2 solubility in acetonitrile of more than one magnitude order (from 0.06 M to 1.1 M) opening new interesting horizons for the possible applications of this vanadium complex. The electrochemical effect of the considered ionic liquids has been subsequently investigated through cyclic voltammetry and linear sweep voltammetry with rotating disk electrode, determining diffusion coefficient and kinetic current of VO(acac)2 in the considered media. In order to achieve a deeper understanding on the examined systems, VO(acac)2 solutions in acetonitrile ILs were eventually studied through IR, UV– vis, and EPR spectroscopies, finding evidences, corroborated by DFT studies, of the formation of strong adducts between VO(acac)2 and ILs.