Abstract
Despite the concurrence of histidine and cysteine in the active sites of proteins associated with Zn2+, Cd2+ and Hg2+, coordination studies of these metal ions with chelating ligands containing a combination of aromatic amine and alkylthiolate (NAxSy−) donors have been rare. The potentially tetradentate ligand 2-[bis(2-pyridinylmethyl)amino]ethanethiol (LH) and chloride salts were used to prepare new complexes of Cd2+ and Hg2+ for comparison with the known Zn2+ complex. Solution NMR studies revealed concentration-dependent equilibria between aggregate forms of the new complexes in CD3CN. Trends in homonuclear and heteronuclear coupling provided additional insight regarding solution equilibria. ESI-MS from acetonitrile solutions supported differences in preferred aggregation states consistent with the solution NMR studies.