Oxo versus sulfido coordination at tungsten: a spectroscopic and correlated ab initio electronic structure study

Sproules, S. (2021) Oxo versus sulfido coordination at tungsten: a spectroscopic and correlated ab initio electronic structure study. Inorganic Chemistry, 60(12), pp. 9057-9063. (doi: 10.1021/acs.inorgchem.1c01055) (PMID:34096284)

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Abstract

The tungsten ion that resides at the active site of a unique class of enzymes only found in esoteric hyperthermophilic archaea bacteria is known to possess at least one terminal chalcogenide ligand. The identity of this as either an oxo or sulfido (or both) is difficult to ascertain from structural studies; therefore, small-molecule analogues are developed to calibrate and substantiate spectroscopic signatures obtained from native proteins. The electronic structures of Tp*WECl2 (E = O, S; Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) have been scrutinized using electronic, electron paramagnetic resonance (EPR), and X-ray absorption spectroscopy to assess the impact of terminal chalcogen on the adjacent cis chloride ligands. Examination at the Cl K-edge provides a direct probe of the bonding and therein lability of these chloride ligands, and in conjunction with density functional theoretical and multireference calculations reveals greater bond covalency in Tp*WOCl2 compared to Tp*WSCl2. The computational model and electronic structure assignment are corroborated by the reproduction of spin-Hamiltonian parameters, whose magnitude is dominated by the sizeable spin–orbit coupling of tungsten.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Sproules, Dr Stephen
Authors: Sproules, S.
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:07 June 2021
Copyright Holders:Copyright © 2021 American Chemical Society
First Published:First published in Inorganic Chemistry 60(12): 9057-9063
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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