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Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept

Using a set of state-of-the-art quantum chemical techniques we scrutinized the characteristically different reactivity of frustrated and classical Lewis pairs towards molecular hydrogen. The mechanisms and reaction profiles computed for the H(2) splitting reaction of various Lewis pairs are in good...

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Autores principales: Skara, Gabriella, De Vleeschouwer, Freija, Geerlings, Paul, De Proft, Frank, Pinter, Balazs
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5700139/
https://www.ncbi.nlm.nih.gov/pubmed/29167477
http://dx.doi.org/10.1038/s41598-017-16244-1
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author Skara, Gabriella
De Vleeschouwer, Freija
Geerlings, Paul
De Proft, Frank
Pinter, Balazs
author_facet Skara, Gabriella
De Vleeschouwer, Freija
Geerlings, Paul
De Proft, Frank
Pinter, Balazs
author_sort Skara, Gabriella
collection PubMed
description Using a set of state-of-the-art quantum chemical techniques we scrutinized the characteristically different reactivity of frustrated and classical Lewis pairs towards molecular hydrogen. The mechanisms and reaction profiles computed for the H(2) splitting reaction of various Lewis pairs are in good agreement with the experimentally observed feasibility of H(2) activation. More importantly, the analysis of activation parameters unambiguously revealed the existence of two reaction pathways through a low-energy and a high-energy transition state. An exhaustive scrutiny of these transition states, including their stability, geometry and electronic structure, reflects that the electronic rearrangement in low-energy transition states is fundamentally different from that of high-energy transition states. Our findings reveal that the widespread consensus mechanism of H(2) splitting characterizes activation processes corresponding to high-energy transition states and, accordingly, is not operative for H(2)-activating systems. One of the criteria of H(2)-activation, actually, is the availability of a low-energy transition state that represents a different H(2) splitting mechanism, in which the electrostatic field generated in the cavity of Lewis pair plays a critical role: to induce a strong polarization of H(2) that facilities an efficient end-on acid-H(2) interaction and to stabilize the charge separated “H(+)–H(−)” moiety in the transition state.
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spelling pubmed-57001392017-11-30 Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept Skara, Gabriella De Vleeschouwer, Freija Geerlings, Paul De Proft, Frank Pinter, Balazs Sci Rep Article Using a set of state-of-the-art quantum chemical techniques we scrutinized the characteristically different reactivity of frustrated and classical Lewis pairs towards molecular hydrogen. The mechanisms and reaction profiles computed for the H(2) splitting reaction of various Lewis pairs are in good agreement with the experimentally observed feasibility of H(2) activation. More importantly, the analysis of activation parameters unambiguously revealed the existence of two reaction pathways through a low-energy and a high-energy transition state. An exhaustive scrutiny of these transition states, including their stability, geometry and electronic structure, reflects that the electronic rearrangement in low-energy transition states is fundamentally different from that of high-energy transition states. Our findings reveal that the widespread consensus mechanism of H(2) splitting characterizes activation processes corresponding to high-energy transition states and, accordingly, is not operative for H(2)-activating systems. One of the criteria of H(2)-activation, actually, is the availability of a low-energy transition state that represents a different H(2) splitting mechanism, in which the electrostatic field generated in the cavity of Lewis pair plays a critical role: to induce a strong polarization of H(2) that facilities an efficient end-on acid-H(2) interaction and to stabilize the charge separated “H(+)–H(−)” moiety in the transition state. Nature Publishing Group UK 2017-11-22 /pmc/articles/PMC5700139/ /pubmed/29167477 http://dx.doi.org/10.1038/s41598-017-16244-1 Text en © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Skara, Gabriella
De Vleeschouwer, Freija
Geerlings, Paul
De Proft, Frank
Pinter, Balazs
Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept
title Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept
title_full Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept
title_fullStr Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept
title_full_unstemmed Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept
title_short Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept
title_sort heterolytic splitting of molecular hydrogen by frustrated and classical lewis pairs: a unified reactivity concept
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5700139/
https://www.ncbi.nlm.nih.gov/pubmed/29167477
http://dx.doi.org/10.1038/s41598-017-16244-1
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