Complexes of cadmium(II), mercury(II) and lead(II) with quercetin-5′-sulfonic acid (QSA)

QSA (C15H10O10S.5H(2)O), a ligand, which is non-toxic and well soluble in water, forms complex compounds with cations of toxic metals (Cd, Hg, Pb). New complex compounds with QSA:Cd(C15H9O10S)(2).10H(2)O, Hg(C15H9O10S)(2).8H(2)O, Pb(C15H9O10S)(2).8H(2)O and Pb(C15H8O10S).4H(2)O have been synthesized. Some of their physicochemical properties such as UV-VIS and infrared spectra, mass spectra, thermogravimetric analysis, and solubility were studied. It was found that the obtained compounds are sparingly soluble in water, which points out that QSA could be an antidote against cadmium, lead and mercury. The structures of the obtained compounds have been proposed.