Ruthenium(II) PNN complexes depolymerize many polyesters into diols and polycarbonates into glycols plus methanol via hydrogenation. Notably, polyesters with two methylene units between ester linkages depolymerize to carboxylic acids rather than diols. This methodology represents a new approach for producing useful chemicals from waste plastics.

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.