Preparation and properties of some metal complexes of plumbagin

Abstract

The preparation and the characterisation of the complexes formed by plumbagin, a naturally occumng naphthaquinone with the ions Cu(II), Ni(I1). Co(II), Mn(II), Zn(I1) and Hg(1I) is reported. The stability constants of these complexes in solutlon have been determined u$ng potentiometric titration techniques. The high values observed for the stability constants may have some relevance to support the hypothesis that certain carrier molecules are involved in the uptake of metal ions by plants.