Role of substituents in copper(II) extraction with N,N′-bis(8-quinolyl)malonamides

Abstract

It has been found that substituents on N,N′-bis(8-quinolyl)malonamide play an important role in copper(II) extraction: among the substituents studied, benzyl groups dramatically increased extractability of the malonamide complex. The role of substituents is discussed on the basis of the results of titration and ¹H NMR measurements of copper(II) or nickel(II) complexes as well as copper(II)-extraction experiments. Intramolecular interactions between π electrons of the benzyl group and the metal centre of the complex are proposed to occur.