Preparation, spectroscopy and oxidation of [Re(C3S5)3]– and [ReO(C3S5)2]– complexes and crystal structure of [PPh4][ReO(C3S5)2]
Abstract
Reaction of ReCl5 with Na2[C3S5][C3S52–= 4,5-dimercapto-1,3-dithiole-2-thionate(2–)] in ethanol in the presence of [PPh4]Br gave [PPh4][ReO(C3S5)2]1. The salt [NBun4][Re(C3S5)3]2 was obtained by reaction of ReCl5 with [NBun4]2[Zn(C3S5)2] in acetonitrile. Oxidation reactions of 2 with iodine or [Fe(C5H5)2][PF6] in dichloromethane afforded [Re(C3S5)3](contaminated with 5 or 10% of 2). These oxidized complexes have electrical conductivities of 2.2 × 10–2 and 4.6 × 10–3 S cm–1 at room temperature for compacted pellets. Cyclic voltammetry and electronic absorption spectra of 1 and 2, together with IR, ESR and X-ray photoelectron spectra of the oxidized species of 2 are discussed. X-Ray structure analysis of 1 reveals that the anions having a square-pyramidal geometry around the ReV are separately arranged in the crystal: monoclinic, space group P21/n, a= 12.437(8), b= 25.56(4), c= 11.137(8)Å, β= 105.58(6)° and Z= 4. Block-diagonal least-squares refinement based on 4591 reflections with |Fo| > 3σ(F) converged at R= 0.052.