Nickel Thiolate Complexes as Ligands for Copper and Zinc: Novel Additions to a Library of Binding Modes

Abstract

AbstractThe reactivity of the two nickel complexes [Ni(xbsms)] and [Ni(bsms)2] [H2xbsms = α,α′‐bis(4‐mercapto‐3,3‐dimethyl‐2‐thiabutyl)‐o‐xylene; Hbsms = 4‐mercapto‐3,3‐dimethyl‐1‐phenyl‐2‐thiabutane] towards copper iodide and zinc bromide has been investigated. The reactions yield novel aggregates of higher nuclearity with topologies that are different from previous reports; the nickel complexes in all cases can be considered as didentate S ligands. The X‐ray structure of the novel octanuclear cluster [{Ni(bsms)2}3(CuI)5] shows a unique arrangement in which the cis‐NiS2S′2 units act as didentate ligands to a trigonal‐bipyramidal array of five CuI ions. The tetranuclear structure of [{Ni(xbsms)CuI}2] shows unprecedented asymmetric bridging of the thiolate sulfur atoms, with one of the thiolate groups binding to one copper ion and the other one μ3‐bridging to two copper ions. The complex is located on a crystallographic twofold axis and the complex in a single crystal is enantiomerically pure. The trinuclear complex [Ni2(bsms)3ZnBr3] is formed as a result of dissociation of the didentate bsms ligand from part of the mononuclear complex and reassembly to form a dinuclear core to which the ZnBr3– unit is coordinated to a single thiolate sulfur atom. A complex of stoichiometry [Ni3(xbsms)2(ZnBr3)2] has also been isolated and a structure proposal based on spectroscopic properties is given. All complexes have been characterised by analytical and spectroscopic methods. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)