Complexes of the cupric ion with mono-, di-, and tri-ethanolamine

Abstract

The complexes of mono-, di-, and tri-ethanolamine with copper have been studied by potentiometric, conductimetric, and spectrophotometric methods. Copper–ligand ratios of 1 : 1 and 1 : 2 have been found for the first two, but only 1 : 1 for triethanolamine except perhaps at high concentrations of amine. The hydroxy-groups of the amines when co-ordinated to copper show markedly acid properties, and dissociation constants are obtained for the successive loss of two hydrogens. The uncharged complex thus formed cannot react further in the case of monoethanolamine, but loses a further hydrogen in the other two cases to form an anion.