Complexes of Cu with 2,2'-Dipyridyl and Cyclohexane-1,1-dicarboxylic Acid.

Formation and stability of the mixed complexes of Cu2+-2, 2′-dipyridyl with cyclohexane-1, 1-dicarboxylic acid have been investigated by means of potentiometric measurements of hydrogen ion concentration, at 25° C and in a medium 0.1M (Na,H)ClO4. Complexes as CuDipL and CuDipL2 have been considered. Hamilton test applied to this system cannot confirm or exclude the hypothesis of formation of the complex CuDipL2, whose real existence is considered unlikely on the ground of enthalpic and entropic considerations. Relating the stability of CuDipL to that of other mixed complexes of CuDip L with some 1, 1-dicarboxylic acids previously studied one can point out the influence of the alicyclic ring rigidity on the stability of the mixed complexes.