Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation

<p> Iridium(III) complexes containing a bidentate spectator ligand have emerged as powerful catalyst precursors for water oxidation. Here we investigate the initial steps of the transformation at the iridium center when using complex [IrCp*(pyr-trz)Cl] 1 (Cp* = pentamethylcyclopentadienyl, pyr...

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Detalhes bibliográficos
Autores: Petronilho, Ana, Llobet, Antoni, Albrecht, Martin
Formato: artículo
Fecha de publicación:2014
País:España
Recursos:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2072/305876
Acesso em linha:http://hdl.handle.net/2072/305876
https://doi.org/10.1021/ic501894u
Access Level:acceso abierto
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spelling Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water OxidationPetronilho, AnaLlobet, AntoniAlbrecht, Martin<p> Iridium(III) complexes containing a bidentate spectator ligand have emerged as powerful catalyst precursors for water oxidation. Here we investigate the initial steps of the transformation at the iridium center when using complex [IrCp*(pyr-trz)Cl] 1 (Cp* = pentamethylcyclopentadienyl, pyr-trz = 4-(2-pyridyl)-1,2,3-triazol-5-ylidene), a potent water oxidation catalyst precursor. Ligand exchange with water is facile and is reversed in the presence of chloride ions, while MeCN substitution is effective only from the corresponding aqua complex. A pKa of 8.3 for the aqua complex was determined, which is in agreement with strong electron donation from the triazolylidene ligand that is comparable to aryl anions. Evaluation of the pH-dependent oxidation process in aqueous media reveals two regimes (pH 4&ndash;8.5 and above pH 10.5) where proton-coupled electron transfer processes occur. These investigations will help to further optimize water oxidation catalysts and indicate that MeCN as a cosolvent has adverse effects for initiating water coordination in the oxidation process.</p>American Chemical Society2014info:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/2072/305876https://doi.org/10.1021/ic501894uRECERCAT (Dipòsit de la Recerca de Catalunya)reponame:Recercat. Dipósit de la Recerca de Catalunyainstname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)InglésMINECO with FEDER FundsProyectos I+D+I - Retos 2013PRO-HInorganic ChemistryCTQ2013-49075-RCopyright © 2014 American Chemical Societyinfo:eu-repo/semantics/openAccessoai:recercat.cat:2072/3058762026-05-29T05:05:01Z
dc.title.none.fl_str_mv Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation
title Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation
spellingShingle Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation
Petronilho, Ana
title_short Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation
title_full Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation
title_fullStr Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation
title_full_unstemmed Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation
title_sort Ligand Exchange and Redox Processes in Iridium Triazolylidene Complexes Relevant to Catalytic Water Oxidation
dc.creator.none.fl_str_mv Petronilho, Ana
Llobet, Antoni
Albrecht, Martin
author Petronilho, Ana
author_facet Petronilho, Ana
Llobet, Antoni
Albrecht, Martin
author_role author
author2 Llobet, Antoni
Albrecht, Martin
author2_role author
author
description <p> Iridium(III) complexes containing a bidentate spectator ligand have emerged as powerful catalyst precursors for water oxidation. Here we investigate the initial steps of the transformation at the iridium center when using complex [IrCp*(pyr-trz)Cl] 1 (Cp* = pentamethylcyclopentadienyl, pyr-trz = 4-(2-pyridyl)-1,2,3-triazol-5-ylidene), a potent water oxidation catalyst precursor. Ligand exchange with water is facile and is reversed in the presence of chloride ions, while MeCN substitution is effective only from the corresponding aqua complex. A pKa of 8.3 for the aqua complex was determined, which is in agreement with strong electron donation from the triazolylidene ligand that is comparable to aryl anions. Evaluation of the pH-dependent oxidation process in aqueous media reveals two regimes (pH 4&ndash;8.5 and above pH 10.5) where proton-coupled electron transfer processes occur. These investigations will help to further optimize water oxidation catalysts and indicate that MeCN as a cosolvent has adverse effects for initiating water coordination in the oxidation process.</p>
publishDate 2014
dc.date.none.fl_str_mv 2014
dc.type.none.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/2072/305876
https://doi.org/10.1021/ic501894u
url http://hdl.handle.net/2072/305876
https://doi.org/10.1021/ic501894u
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv MINECO with FEDER Funds
Proyectos I+D+I - Retos 2013
PRO-H
Inorganic Chemistry
CTQ2013-49075-R
dc.rights.none.fl_str_mv Copyright © 2014 American Chemical Society
info:eu-repo/semantics/openAccess
rights_invalid_str_mv Copyright © 2014 American Chemical Society
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
dc.source.none.fl_str_mv RECERCAT (Dipòsit de la Recerca de Catalunya)
reponame:Recercat. Dipósit de la Recerca de Catalunya
instname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
instname_str Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
reponame_str Recercat. Dipósit de la Recerca de Catalunya
collection Recercat. Dipósit de la Recerca de Catalunya
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,812429

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