Cargando…

Electronic characterization of redox (non)-innocent Fe(2)S(2) reference systems: a multi K-edge X-ray spectroscopic study

Di-iron dithiolate hydrogenase model complexes are promising systems for electrocatalytic production of dihydrogen and have therefore been spectroscopically and theoretically investigated in this study. The direct effect of ligand substitution on the redox activity of the complex is examined. In ord...

Descripción completa

Detalles Bibliográficos
Autores principales: Oudsen, J. P. H., Venderbosch, B., Korstanje, T. J., Tromp, M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9048190/
https://www.ncbi.nlm.nih.gov/pubmed/35494446
http://dx.doi.org/10.1039/c9ra08903a
_version_ 1784695881356804096
author Oudsen, J. P. H.
Venderbosch, B.
Korstanje, T. J.
Tromp, M.
author_facet Oudsen, J. P. H.
Venderbosch, B.
Korstanje, T. J.
Tromp, M.
author_sort Oudsen, J. P. H.
collection PubMed
description Di-iron dithiolate hydrogenase model complexes are promising systems for electrocatalytic production of dihydrogen and have therefore been spectroscopically and theoretically investigated in this study. The direct effect of ligand substitution on the redox activity of the complex is examined. In order to understand and eventually optimize such systems, we characterised both metal and ligand in detail, using element specific X-ray absorption Fe- and S-K edge XAS. The (electronic) structure of three different [Fe(2)S(2)] hydrogenase systems in their non-reduced state was investigated. The effect of one- and two-electron reduction on the (electronic) structure was subsequently investigated. The S K-edge XAS spectra proved to be sensitive to delocalization of the electron density into the aromatic ring. The earlier postulated charge and spin localization in these complexes could now be measured directly using XANES. Moreover, the electron density (from S K-edge XANES) could be directly correlated to the Fe–CO bond length (from Fe K-edge EXAFS), which are in turn both related to the reported catalytic activity of these complexes. The delocalization of the electron density into the conjugated π-system of the aromatic moieties lowers the basicity of the diiron core and since protonation occurs at the diiron (as a rate determining step), lowering the basicity decreases the extent of protonation and consequently the catalytic activity.
format Online
Article
Text
id pubmed-9048190
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher The Royal Society of Chemistry
record_format MEDLINE/PubMed
spelling pubmed-90481902022-04-28 Electronic characterization of redox (non)-innocent Fe(2)S(2) reference systems: a multi K-edge X-ray spectroscopic study Oudsen, J. P. H. Venderbosch, B. Korstanje, T. J. Tromp, M. RSC Adv Chemistry Di-iron dithiolate hydrogenase model complexes are promising systems for electrocatalytic production of dihydrogen and have therefore been spectroscopically and theoretically investigated in this study. The direct effect of ligand substitution on the redox activity of the complex is examined. In order to understand and eventually optimize such systems, we characterised both metal and ligand in detail, using element specific X-ray absorption Fe- and S-K edge XAS. The (electronic) structure of three different [Fe(2)S(2)] hydrogenase systems in their non-reduced state was investigated. The effect of one- and two-electron reduction on the (electronic) structure was subsequently investigated. The S K-edge XAS spectra proved to be sensitive to delocalization of the electron density into the aromatic ring. The earlier postulated charge and spin localization in these complexes could now be measured directly using XANES. Moreover, the electron density (from S K-edge XANES) could be directly correlated to the Fe–CO bond length (from Fe K-edge EXAFS), which are in turn both related to the reported catalytic activity of these complexes. The delocalization of the electron density into the conjugated π-system of the aromatic moieties lowers the basicity of the diiron core and since protonation occurs at the diiron (as a rate determining step), lowering the basicity decreases the extent of protonation and consequently the catalytic activity. The Royal Society of Chemistry 2020-01-02 /pmc/articles/PMC9048190/ /pubmed/35494446 http://dx.doi.org/10.1039/c9ra08903a Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/
spellingShingle Chemistry
Oudsen, J. P. H.
Venderbosch, B.
Korstanje, T. J.
Tromp, M.
Electronic characterization of redox (non)-innocent Fe(2)S(2) reference systems: a multi K-edge X-ray spectroscopic study
title Electronic characterization of redox (non)-innocent Fe(2)S(2) reference systems: a multi K-edge X-ray spectroscopic study
title_full Electronic characterization of redox (non)-innocent Fe(2)S(2) reference systems: a multi K-edge X-ray spectroscopic study
title_fullStr Electronic characterization of redox (non)-innocent Fe(2)S(2) reference systems: a multi K-edge X-ray spectroscopic study
title_full_unstemmed Electronic characterization of redox (non)-innocent Fe(2)S(2) reference systems: a multi K-edge X-ray spectroscopic study
title_short Electronic characterization of redox (non)-innocent Fe(2)S(2) reference systems: a multi K-edge X-ray spectroscopic study
title_sort electronic characterization of redox (non)-innocent fe(2)s(2) reference systems: a multi k-edge x-ray spectroscopic study
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9048190/
https://www.ncbi.nlm.nih.gov/pubmed/35494446
http://dx.doi.org/10.1039/c9ra08903a
work_keys_str_mv AT oudsenjph electroniccharacterizationofredoxnoninnocentfe2s2referencesystemsamultikedgexrayspectroscopicstudy
AT venderboschb electroniccharacterizationofredoxnoninnocentfe2s2referencesystemsamultikedgexrayspectroscopicstudy
AT korstanjetj electroniccharacterizationofredoxnoninnocentfe2s2referencesystemsamultikedgexrayspectroscopicstudy
AT trompm electroniccharacterizationofredoxnoninnocentfe2s2referencesystemsamultikedgexrayspectroscopicstudy