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C–H Bond Activation and C–C Coupling of Methane on a Single Cationic Platinum Center: A Spectroscopic and Theoretical Study
[Image: see text] We spectroscopically investigated the activation products resulting from reacting one and multiple methane molecules with Pt(+) ions. Pt(+) ions were formed by laser ablation of a metal target and were cooled to the electronic ground state in a supersonic expansion. The ions were t...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2022
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9326971/ https://www.ncbi.nlm.nih.gov/pubmed/35819891 http://dx.doi.org/10.1021/acs.inorgchem.2c01328 |
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author | Wensink, Frank J. Roos, Noa Bakker, Joost M. Armentrout, P. B. |
author_facet | Wensink, Frank J. Roos, Noa Bakker, Joost M. Armentrout, P. B. |
author_sort | Wensink, Frank J. |
collection | PubMed |
description | [Image: see text] We spectroscopically investigated the activation products resulting from reacting one and multiple methane molecules with Pt(+) ions. Pt(+) ions were formed by laser ablation of a metal target and were cooled to the electronic ground state in a supersonic expansion. The ions were then transferred to a room temperature ion trap, where they were reacted with methane at various partial pressures in an argon buffer gas. Product masses observed were [Pt,C,2H](+), [Pt,2C,4H](+), [Pt,4C,8H](+), and [Pt,2C,O,6H](+), which were mass-isolated and characterized using infrared multiple-photon dissociation (IRMPD) spectroscopy employing the free electron laser for intra-cavity experiments (FELICE). The spectra for [Pt,2C,4H](+) and [Pt,4C,8H](+) have several well-defined bands and, when compared to density functional theory-calculated spectra for several possible product structures, lead to unambiguous assignments to species with ethene ligands, proving Pt(+)-mediated C–C coupling involving up to four methane molecules. These findings contrast with earlier experiments where Pt(+) ions were reacted in a flow-tube type reaction channel at significantly higher pressures of helium buffer gas, resulting in the formation of a Pt(CH(3))(2)(+) product. Our DFT calculations show a reaction barrier of +0.16 eV relative to the PtCH(2)(+) + CH(4) reactants that are required for C–C coupling. The different outcomes in the two experiments suggest that the higher pressure in the earlier work could kinetically trap the dimethyl product, whereas the lower pressure and longer residence times in the ion trap permit the reaction to proceed, resulting in ethene formation and dihydrogen elimination. |
format | Online Article Text |
id | pubmed-9326971 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-93269712022-07-28 C–H Bond Activation and C–C Coupling of Methane on a Single Cationic Platinum Center: A Spectroscopic and Theoretical Study Wensink, Frank J. Roos, Noa Bakker, Joost M. Armentrout, P. B. Inorg Chem [Image: see text] We spectroscopically investigated the activation products resulting from reacting one and multiple methane molecules with Pt(+) ions. Pt(+) ions were formed by laser ablation of a metal target and were cooled to the electronic ground state in a supersonic expansion. The ions were then transferred to a room temperature ion trap, where they were reacted with methane at various partial pressures in an argon buffer gas. Product masses observed were [Pt,C,2H](+), [Pt,2C,4H](+), [Pt,4C,8H](+), and [Pt,2C,O,6H](+), which were mass-isolated and characterized using infrared multiple-photon dissociation (IRMPD) spectroscopy employing the free electron laser for intra-cavity experiments (FELICE). The spectra for [Pt,2C,4H](+) and [Pt,4C,8H](+) have several well-defined bands and, when compared to density functional theory-calculated spectra for several possible product structures, lead to unambiguous assignments to species with ethene ligands, proving Pt(+)-mediated C–C coupling involving up to four methane molecules. These findings contrast with earlier experiments where Pt(+) ions were reacted in a flow-tube type reaction channel at significantly higher pressures of helium buffer gas, resulting in the formation of a Pt(CH(3))(2)(+) product. Our DFT calculations show a reaction barrier of +0.16 eV relative to the PtCH(2)(+) + CH(4) reactants that are required for C–C coupling. The different outcomes in the two experiments suggest that the higher pressure in the earlier work could kinetically trap the dimethyl product, whereas the lower pressure and longer residence times in the ion trap permit the reaction to proceed, resulting in ethene formation and dihydrogen elimination. American Chemical Society 2022-07-12 2022-07-25 /pmc/articles/PMC9326971/ /pubmed/35819891 http://dx.doi.org/10.1021/acs.inorgchem.2c01328 Text en © 2022 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Wensink, Frank J. Roos, Noa Bakker, Joost M. Armentrout, P. B. C–H Bond Activation and C–C Coupling of Methane on a Single Cationic Platinum Center: A Spectroscopic and Theoretical Study |
title | C–H
Bond Activation and C–C Coupling
of Methane on a Single Cationic Platinum Center: A Spectroscopic and
Theoretical Study |
title_full | C–H
Bond Activation and C–C Coupling
of Methane on a Single Cationic Platinum Center: A Spectroscopic and
Theoretical Study |
title_fullStr | C–H
Bond Activation and C–C Coupling
of Methane on a Single Cationic Platinum Center: A Spectroscopic and
Theoretical Study |
title_full_unstemmed | C–H
Bond Activation and C–C Coupling
of Methane on a Single Cationic Platinum Center: A Spectroscopic and
Theoretical Study |
title_short | C–H
Bond Activation and C–C Coupling
of Methane on a Single Cationic Platinum Center: A Spectroscopic and
Theoretical Study |
title_sort | c–h
bond activation and c–c coupling
of methane on a single cationic platinum center: a spectroscopic and
theoretical study |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9326971/ https://www.ncbi.nlm.nih.gov/pubmed/35819891 http://dx.doi.org/10.1021/acs.inorgchem.2c01328 |
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