Cargando…

Kinetics and mechanistic details of bulk ZnO dissolution using a thiol–imidazole system

Oxide dissolution is important for metal extraction from ores and has become an attractive route for the preparation of inks for thin film solution deposition; however, oxide dissolution is often kinetically challenging. While binary “alkahest” systems comprised of thiols and N-donor species, such a...

Descripción completa

Detalles Bibliográficos
Autores principales: Koskela, Kristopher M., Quiton, Stephen J., Sharada, Shaama Mallikarjun, Williams, Travis J., Brutchey, Richard L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8926287/
https://www.ncbi.nlm.nih.gov/pubmed/35414876
http://dx.doi.org/10.1039/d1sc06667f
_version_ 1784670209331691520
author Koskela, Kristopher M.
Quiton, Stephen J.
Sharada, Shaama Mallikarjun
Williams, Travis J.
Brutchey, Richard L.
author_facet Koskela, Kristopher M.
Quiton, Stephen J.
Sharada, Shaama Mallikarjun
Williams, Travis J.
Brutchey, Richard L.
author_sort Koskela, Kristopher M.
collection PubMed
description Oxide dissolution is important for metal extraction from ores and has become an attractive route for the preparation of inks for thin film solution deposition; however, oxide dissolution is often kinetically challenging. While binary “alkahest” systems comprised of thiols and N-donor species, such as amines, are known to dissolve a wide range of oxides, the mechanism of dissolution and identity of the resulting solute(s) remain unstudied. Here, we demonstrate facile dissolution of both bulk synthetic and natural mineral ZnO samples using an “alkahest” that operates via reaction with thiophenol and 1-methylimidazole (MeIm) to give a single, pseudotetrahedral Zn(SPh)(2)(MeIm)(2) molecular solute identified by X-ray crystallography. The kinetics of ZnO dissolution were measured using solution (1)H NMR, and the reaction was found to be zero-order in the presence of excess ligands, with more electron withdrawing para-substituted thiophenols resulting in faster dissolution. A negative entropy of activation was measured by Eyring analysis, indicating associative ligand binding in, or prior to, the rate determining step. Combined experimental and computational surface binding studies on ZnO reveal stronger, irreversible thiophenol binding compared to MeIm, leading to a proposed dissolution mechanism initiated by thiol binding to the ZnO surface with the liberation of water, followed by alternating MeIm and thiolate ligand additions, and ultimately cleavage of the ligated zinc complex from the ZnO surface. Design rules garnered from the mechanistic insight provided by this study should inform the dissolution of other bulk oxides into inks for solution processed thin films.
format Online
Article
Text
id pubmed-8926287
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher The Royal Society of Chemistry
record_format MEDLINE/PubMed
spelling pubmed-89262872022-04-11 Kinetics and mechanistic details of bulk ZnO dissolution using a thiol–imidazole system Koskela, Kristopher M. Quiton, Stephen J. Sharada, Shaama Mallikarjun Williams, Travis J. Brutchey, Richard L. Chem Sci Chemistry Oxide dissolution is important for metal extraction from ores and has become an attractive route for the preparation of inks for thin film solution deposition; however, oxide dissolution is often kinetically challenging. While binary “alkahest” systems comprised of thiols and N-donor species, such as amines, are known to dissolve a wide range of oxides, the mechanism of dissolution and identity of the resulting solute(s) remain unstudied. Here, we demonstrate facile dissolution of both bulk synthetic and natural mineral ZnO samples using an “alkahest” that operates via reaction with thiophenol and 1-methylimidazole (MeIm) to give a single, pseudotetrahedral Zn(SPh)(2)(MeIm)(2) molecular solute identified by X-ray crystallography. The kinetics of ZnO dissolution were measured using solution (1)H NMR, and the reaction was found to be zero-order in the presence of excess ligands, with more electron withdrawing para-substituted thiophenols resulting in faster dissolution. A negative entropy of activation was measured by Eyring analysis, indicating associative ligand binding in, or prior to, the rate determining step. Combined experimental and computational surface binding studies on ZnO reveal stronger, irreversible thiophenol binding compared to MeIm, leading to a proposed dissolution mechanism initiated by thiol binding to the ZnO surface with the liberation of water, followed by alternating MeIm and thiolate ligand additions, and ultimately cleavage of the ligated zinc complex from the ZnO surface. Design rules garnered from the mechanistic insight provided by this study should inform the dissolution of other bulk oxides into inks for solution processed thin films. The Royal Society of Chemistry 2022-02-25 /pmc/articles/PMC8926287/ /pubmed/35414876 http://dx.doi.org/10.1039/d1sc06667f Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by-nc/3.0/
spellingShingle Chemistry
Koskela, Kristopher M.
Quiton, Stephen J.
Sharada, Shaama Mallikarjun
Williams, Travis J.
Brutchey, Richard L.
Kinetics and mechanistic details of bulk ZnO dissolution using a thiol–imidazole system
title Kinetics and mechanistic details of bulk ZnO dissolution using a thiol–imidazole system
title_full Kinetics and mechanistic details of bulk ZnO dissolution using a thiol–imidazole system
title_fullStr Kinetics and mechanistic details of bulk ZnO dissolution using a thiol–imidazole system
title_full_unstemmed Kinetics and mechanistic details of bulk ZnO dissolution using a thiol–imidazole system
title_short Kinetics and mechanistic details of bulk ZnO dissolution using a thiol–imidazole system
title_sort kinetics and mechanistic details of bulk zno dissolution using a thiol–imidazole system
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8926287/
https://www.ncbi.nlm.nih.gov/pubmed/35414876
http://dx.doi.org/10.1039/d1sc06667f
work_keys_str_mv AT koskelakristopherm kineticsandmechanisticdetailsofbulkznodissolutionusingathiolimidazolesystem
AT quitonstephenj kineticsandmechanisticdetailsofbulkznodissolutionusingathiolimidazolesystem
AT sharadashaamamallikarjun kineticsandmechanisticdetailsofbulkznodissolutionusingathiolimidazolesystem
AT williamstravisj kineticsandmechanisticdetailsofbulkznodissolutionusingathiolimidazolesystem
AT brutcheyrichardl kineticsandmechanisticdetailsofbulkznodissolutionusingathiolimidazolesystem