Characterization of the first N2S(alkylthiolate)lead compound:: A model for three-coordinate lead in biological systems

A new N2S(alkylthiolate)-coordinated Pb2+ compound {2-methyl-1-[ methyl(2-pyridin-2-ylethyl)amino]propane-2-thiolatolead perchlorate, [PATH-Pb][ClO4]} has been synthesized and characterized by X-ray diffraction and by Pb-207 NMR. [PATH-Pb](+) is the first reported three-coordinate Pb complex with an alkanethiolate ligand and, hence, is a good model for Pb-cysteine interactions in proteins. The Pb center displays distorted trigonal-planar geometry. The Pb-S bond lengths are extremely short (2.590(10) and 2.597(10) angstrom for two distinct monomers in the unit cell). Pb-207 NMR revealed a Pb resonance at 5318 ppm, much further downfield than Pb complexes with N and O ligation. Given recent evidence of three-coordinate Pb-binding in proteins with cysteine-rich metal-binding sites, [PATH-Pb](+) is an important model for Pb sites in biological systems. Crystal data: C12H19N2SPbClO4, M-r = 529.99, monoclinic, P2(1)/n, a = 16.8297(9) angstrom, b = 11.9719(6) angstrom, c = 17.0868(9) angstrom, V = 3237.7(3) angstrom(3), and Z = 8.