Oxidation reduction studies in non-aqeous media

Abstract

This thesis embodies the results of the investigations on the oxidation-reduction behaviour of two typical redox couples in non~aqueous media. The redox systems chosen for the studies are (i) Copper(II) - Copper(l) couple in acetonitrile and (ii) Cerium(IV) - Cerium(lII) couple in tri-n-butyl phosphate. Acetonitrile is a good solvent for both oupric and cuprous salts. Solut* i* *o,» n:s• • »*of these salts in acetonitrile keep their strength" for a fairly long period when properly preserved. ' Copper(ll) perchlorate, nitrate and chloride function as powerful oxidising agents towardsboth organic and inorganic reducing agents in acetonitrile. Analytical procedures have been evolved for the estimation of xanthates, iodides, thiourea and hydroquinone based on these reactions. The interaction between copper(II) ions and these reducing agents in acetonitrile is distinctly different from the interaction in aqueous mediiim. Copper(ll) salts show a gradation in their oxidation capacities depending on the anion associated with copper. The measurement of formal redox potentials of these systems confirms such an observation. Tri-n-butyl phosphate is another widely used industrial solvent employed for the extraction of cerium(IV) and other rare earths. Ceriimi(lT) salts particularly the hexanitratocerate is highly soluble in this solvent and such solutions can conveniently be employed for the oxidation of both organic and inorganic reducing agents.