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

The reactivity of the two nickel complexes [Ni(xbsms)] and [Ni(bsms) 2 ] [H 2 xbsms = 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 ‐NiS 2 S′ 2 units act as didentate ligands to a trigonal‐bipyramidal array of five Cu I 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 μ 3 ‐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 [Ni 2 (bsms) 3 ZnBr 3 ] 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 ZnBr 3 – unit is coordinated to a single thiolate sulfur atom. A complex of stoichiometry [Ni 3 (xbsms) 2 (ZnBr 3 ) 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)