Studies of indirect electrochemical reductions using chromium complexes with polyaminocarboxylate ligands as mediators

Abstract The electrochemical preparations of Cr(II)EDTA and related Cr(II) polyaminocarboxylate complexes is weakly acidic, aqueous media are described and their reactions with organic molecules are discussed. It is confirmed that the Cr(II)L complexes are strong reducing agents capable of some interesting transformations but these chemical reactions are generally slow and, hence, an indirect electrosynthesis would have to be carried out ex-cell with a large holding tank. The chemistry of the Cr(II)L complexes and Cr(II) in chloride and sulphate media are compared. The extent of phase transfer of the Cr(III)L and Cr(II)L complexes into water immiscible organic solvents by tetrabutylammonium ion are also reported.