title: A Single-Component Conductor Based on a Radical Gold Dithiolene Complex with Alkyl-Substituted Thiophene-2,3-dithiolate Ligand.
abstract: Alkyl-substituted thiophene-2,3-dithiolate ligands are prepared through a Thio-Claisen rearrangement of 4,5-bis(propargylthio)-1,3-dithiole-2-thione derivatives. The two novel dithiolate ligands, namely, 4,5-dimethyl-thiophene-2,3-dithiolate (α-Me2tpdt) and 4-ethyl-5-methyl-thiophene-2,3-dithiolate (α-EtMetpdt), are engaged in anionic Au(III) square planar complexes formulated as [Au(α-Me2tpdt)2](-) and [Au(α-EtMetpdt)2](-), isolated as Ph4P(+) salts. Monoelectronic oxidation gives the neutral radical complexes [Au(α-Me2tpdt)2](•) and [Au(α-EtMetpdt)2](•). The latter crystallizes into uniform stacks with limited interstack interactions, giving rise to a calculated half-filled band structure. It exhibits a semiconducting behavior with room temperature conductivity of 3 × 10(-3) S cm(-1), indicating that this single-component conductor can be described as a Mott insulator. The different structures observed in [Au(α-EtMetpdt)2](•) and the known [Au(Et-thiazdt)2](•) complex (Et-thiazdt: N-ethyl-thiazoline-2-thione-4,5-dithiolate), despite their very similar shapes, are tentatively attributed to differences in the electronic structures of the ligand skeleton.
authors.affiliation: Institut des Sciences Chimiques de Rennes (ISCR), Université Rennes 1, UMR CNRS 6226, Campus de Beaulieu, 35042 Rennes, France.|Department of Organic and Polymeric Materials, Tokyo Institute of Technology , O-okayama 2-12-1, Meguro-ku, 152-8552, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Higashino
authors.affiliation: Institut des Sciences Chimiques de Rennes (ISCR), Université Rennes 1, UMR CNRS 6226, Campus de Beaulieu, 35042 Rennes, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Jeannin
authors.affiliation: Department of Organic and Polymeric Materials, Tokyo Institute of Technology , O-okayama 2-12-1, Meguro-ku, 152-8552, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kawamoto
authors.affiliation: Institut des Sciences Chimiques de Rennes (ISCR), Université Rennes 1, UMR CNRS 6226, Campus de Beaulieu, 35042 Rennes, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Lorcy
authors.affiliation: Department of Organic and Polymeric Materials, Tokyo Institute of Technology , O-okayama 2-12-1, Meguro-ku, 152-8552, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Mori
authors.affiliation: Institut des Sciences Chimiques de Rennes (ISCR), Université Rennes 1, UMR CNRS 6226, Campus de Beaulieu, 35042 Rennes, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Fourmigué