title: Binuclear complexes of Ni(I) from 4-terphenyldithiophenol.
abstract: Binuclear complexes of Ni(i) have been prepared from a 4-terphenyldithiophenol ligand. Steric effects were found to determine the formation of coordination isomeric structures that differ in the nature of metal-to-ligand bonding. Coordination of spatially demanding phosphine ligands PR3, R = C6H6, C6H11, at nickel sites results in a butterfly shaped thiolate-bridged Ni2(μ-S)2 motif. For smaller PMe3, the central π-system of the 4-terphenyl backbone adopts a bis-allyl like μ-syn-η(3):η(3)-C6H4 structure due to significant d-π* Ni(i)-to-ligand charge transfer. Delocalisation indices δ(Ni-Ni) derived from DFT calculations provide a metric to assess the strength of electronic coupling of the Ni sites based on solid state structural data, and indicated less strong electronic coupling for the bis-allyl like structure with δ(Ni-Ni) = 0.225 as compared to 0.548 for the Ni2(μ-S)2 structural motif. A qualitative reactivity study toward CNCH3 as an auxiliary ligand has provided the first insight into the chemical properties of the bimetallic complexes presented.
authors.affiliation: Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany. andreas.berkefeld@anorg.uni-tuebingen.de.
authors.forename: Felix
authors.initials: F
authors.lastname: Koch
authors.forename: Hartmut
authors.initials: H
authors.lastname: Schubert
authors.forename: Peter
authors.initials: P
authors.lastname: Sirsch
authors.forename: Andreas
authors.initials: A
authors.lastname: Berkefeld