Characterization of the First N₂S(alkylthiolate)lead Compound:  A Model for Three-Coordinate Lead in Biological Systems

Abstract

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 207Pb 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) A for two distinct monomers in the unit cell). 207Pb 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, Mr = 529.99, monoclinic, P2(1)/n, a = 16.8297(9) A, b = 11.9719(6) A, c = 17.0868(9) A, V = 3237.7(3) A3, and Z = 8.

Lead(II) in a sulfur-rich environment: Synthesis and molecular structure of the first dinuclear bis(mercaptoimidazolyl)methane complex

“…Although it is generally believed that the physiological targets of lead(II) ions are primarily the sulfur-rich (or sulfur-only) active sites present in certain calcium-and zinc-binding enzymes, the fundamental coordination preferences that Pb(II) ions display in such environments constitute an active area of research [2][3][4]. In a similar vein, the high affinity of Pb(II) for cysteine and methionine residues is also likely to be responsible for the acquisition and transport of this and other deleterious metal ions by phytochelatins and metallothioneins in plants and animals and is thus relevant to biotechnological applications such as phytoremediation [5].…”

Crystal structure of catena-poly[(1,3,4-thiadiazolium-2-thiolato)lead(II) dichloride], Pb(C2H2N2S2)Cl2

“…One of the most important features influencing the high performance for lead removal is the coordination behavior of Pb ion [4][5][6]. Lead(II) possesses al arge radius, av ariable stereochemical activity, and aflexible coordination, which provides unique opportunities for the construction of novel metal-organic frameworks (MOFs) [7]. Meanwhile, thiadiazoles have attracted increasing attention because of their potential applications in pharmaceutical, agricultural, industrial, coordination and polymer chemistry [8][9][10].…”

Crystal structure of catena-poly[(1,3,4-thiadiazolium-2-thiolato)lead(II) dichloride], Pb(C2H2N2S2)Cl2

“…The control of heavy-metal lead in industrial effluents is of crucial importance for environmental reasons. One of the most important features influencing the high performance for lead removal is the coordination behavior of Pb ion [4][5][6], Lead(II) possesses a large radius, a variable stereochemical activity, and a flexible coordination, which provides unique opportunities for the construction of novel metal-organic frameworks (MOFs) [7]. Meanwhile, thiadiazoles have attracted increasing attention because of their potential applications in pharmaceutical, agricultural, industrial, coordination and polymer chemistry [8][9][10].…”