Mononuclear sulfido-tungsten(V) complexes: completing the Tp*MEXY (M = Mo, W; E = O, S) series

Sproules, S. , Eagle, A. A., George, G. N., White, J. M. and Young, C. G. (2017) Mononuclear sulfido-tungsten(V) complexes: completing the Tp*MEXY (M = Mo, W; E = O, S) series. Inorganic Chemistry, 56(9), pp. 5189-5202. (doi: 10.1021/acs.inorgchem.7b00331) (PMID:28414431)

Abstract

Orange Tp*WSCl2 has been synthesized from the reactions of Tp*WOCl2 with boron sulfide in refluxing toluene or Tp*WS2Cl with PPh3 in dichloromethane at room temperature. Mononuclear sulfido-tungsten(V) complexes, Tp*WSXY {X = Y = Cl, OPh, SPh, SePh; X = Cl, Y = OPh; XY = toluene-3,4-dithiolate (tdt), quinoxaline-2,3-dithiolate (qdt); and Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate} were prepared by metathesis of Tp*WSCl2 with the respective alkali metal salt of X–/XY2–, or [NHEt3]2(qdt). The complexes were characterized by microanalysis, mass spectrometry, electrochemistry, and infrared (IR), electron paramagnetic resonance (EPR) and electronic absorption spectroscopies. The molecular structures of Tp*WS(OPh)2, Tp*WS(SePh)2, and Tp*WS(tdt) have been determined by X-ray crystallography. The six-coordinate, distorted-octahedral W centers are coordinated by terminal sulfido (W≡S = 2.128(2) – 2.161(1) Å), terdentate facial Tp*, and monodentate/bidentate O/S/Se-donor ligands. The sulfido-W(V) complexes are characterized by lower energy electronic transitions, smaller giso, and larger Aiso(183W) values, and more positive reduction potentials compared with their oxo-W(V) counterparts. This series has been probed by sulfur K-edge X-ray absorption spectroscopy (XAS), the spectra being assigned by comparison to Tp*WOXY (X = Y = SPh; XY = tdt, qdt) and time-dependent density functional theoretical (TD-DFT) calculations. This study provides insight into the electronic nature and chemistry of the catalytically and biologically important sulfido-W unit.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sproules, Dr Stephen
• Authors: Sproules, S., Eagle, A. A., George, G. N., White, J. M., and Young, C. G.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Inorganic Chemistry
• Publisher: American Chemical Society
• ISSN: 0020-1669
• ISSN (Online): 1520-510X
• Published Online: 17 April 2017
• Copyright Holders: Copyright © 2017 American Chemical Society
• First Published: First published in Inorganic Chemistry 56(9): 5189-5202
• Publisher Policy: Reproduced in accordance with the publisher copyright policy