PHYSICO-CHEMICAL STUDIES ON COMPOSITION AND STABILITY OF COPPER CHELATES OF 2-HYDROXYSTEARIC AND 2-HYDROXYDOCOSANOIC ACIDS

The complex formation of copper (II) with 2-hydroxystearic and 2-hydroxydocosanoic acids has been investigated at pH 8.0 in a medium of m-xylene-ethanol (75:25 v/v). The formation of only one complex metal: ligand (1:2) is detected by three independent methods, viz. Job's method of continuous variation, conductometric titration and chemical analysis of the isolated complexes. The logarithm of the formation constants (log K) as calculated by the method of Turner and Anderson are 6.30 and 5.73 and the free energy change of combination are, -8.590 kcal and -7.814 kcal respectively. A chelate structure for both the complexes, in which the ligand molecules act as a bidentate chelating species involving the weakly coordinating hydroxyl group in bond formation has been suggested by analogy with the copper derivatives of amino acids. © 1969 American Oil Chemists' Society.