title: Do S,S'-coordinated o-dithiobenzosemiquinonate(1-) radicals exist in coordination compounds? the [AuIII(1,2-C6H4S2)2]1 -/0 couple.
abstract: The square planar, light-green, diamagnetic complex [N(n-Bu)(4)][Au(III)(L(t)()(-)(Bu))(2)] (1) reacts with iodine in acetone affording the neutral paramagnetic species [Au(L(t)()(-)(Bu))(2)] (1a) (S = (1)/(2)) where H(2)[L(t)()(-)(Bu)] represents the ligand 3,5-di-tert-butyl-1,2-benzenedithiol. The corresponding complexes containing the unsubstituted ligand H(2)[L], 1,2-benzenedithiol, namely [N(n-Bu)(3)H][Au(L)(2)] (2) and [Au(L)(2)] (2a), have also been prepared and characterized by X-ray crystallography; the structure of the latter has been reported in ref 10. (197)Au Mössbauer spectra of 1 and 1a clearly show that the one-electron oxidation is ligand-centered and does not involve the formation of Au(IV) (d(7)). The spectroscopic features of the ligand mixed-valent species 1a were determined by UV-vis, EPR, and IR spectroscopy which allows the detection of S,S-coordinated 1,2-dithiobenzosemiquinonate(1-) radicals in coordination compounds.
authors.affiliation: Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Kallol
authors.initials: K
authors.lastname: Ray
authors.forename: Thomas
authors.initials: T
authors.lastname: Weyhermüller
authors.forename: Anton
authors.initials: A
authors.lastname: Goossens
authors.forename: Menno W J
authors.initials: MW
authors.lastname: Crajé
authors.forename: Karl
authors.initials: K
authors.lastname: Wieghardt