Equilibria and speciation of metal complexes important in hydrometallurgy. Part 3. Studies of the copper(II) complexes of 5-nonylsalicylaldoxime (Acorga P50), the effect of 4-nonylphenol and the formation of five-co-ordinate adducts with nitrogenous bases

Abstract

Copper complexes of the ‘Acorga P5000’ series of reagents have been studied by electronic and e.s.r. spectroscopy. The P5000 series solvent extraction reagents contain as the major complexing agent 5-nonylsalicylaldoxime; this ligand forms a stable bis-chelated complex with copper(II) in the organic phase. The common additive 4-nonylphenol does not interact with the first co-ordination sphere of the copper(II) complex in the organic phase. In contrast, both pyridine and ammonia form five-co-ordinate adducts with the complex. The equilibrium constant has been determined as 40 dm³ mol^–1 for the binding of pyridine to the bis(salicylaldoxime) complex in toluene.