Marcus cross relation in the space of H-atom abstraction reactions boosted through off-diagonal thermodynamics

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F25%3A00640180" target="_blank" >RIV/61388963:_____/25:00640180 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61388955:_____/25:00640180 RIV/68407700:21340/25:00386244

Výsledek na webu

<a href="https://pubs.aip.org/aip/jcp/article/163/14/144105/3366960/Marcus-cross-relation-in-the-space-of-H-atom" target="_blank" >https://pubs.aip.org/aip/jcp/article/163/14/144105/3366960/Marcus-cross-relation-in-the-space-of-H-atom</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0289063" target="_blank" >10.1063/5.0289063</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Marcus cross relation in the space of H-atom abstraction reactions boosted through off-diagonal thermodynamics

Popis výsledku v původním jazyce

Proton-coupled electron transfer (PCET) and hydrogen-atom transfer (HAT) reactions, collectively called H-atom abstraction (HAA) reactions, play critical roles in biological processes and modern organic synthesis. The kinetics of these processes can align with the principles described in the renowned Marcus cross relation (MCR), a framework initially formulated to describe electron transfer mechanisms. The MCR provides an outstanding link between the kinetics of HAA reactions involving two distinct reactants and two related auxiliary self-exchange reactions—each between a molecule of one of the reactants and its conjugated radical. In this study, we investigate the applicability and limitations of the canonical MCR across over 300 HAA reactions, providing a comprehensive theoretical analysis. Our findings reveal the need for an enhanced framework that incorporates “off-diagonal” thermodynamic factors—asynchronicity and frustration. Of these factors, asynchronicity, which quantifies the imbalance between the proton vs electron transfer components of the reaction, is identified as the dominant contributor to the improved predictive accuracy of the MCR. Notably, the incorporation of off-diagonal thermodynamics yields a more pronounced enhancement for HAT reactions than for PCET-like HAA reactions. As a corollary, the model also describes a so-called pseudoinverted region, in which more exergonic reactions feature higher free energy barriers even though the thermodynamic driving force is not so large as it is required for the proper inverted region well-known from the original Marcus theory. This advancement offers a refined theoretical basis for understanding H-atom abstraction mechanisms and underscores the importance of off-diagonal effects in HAA chemistry.

Název v anglickém jazyce

Marcus cross relation in the space of H-atom abstraction reactions boosted through off-diagonal thermodynamics

Popis výsledku anglicky

Proton-coupled electron transfer (PCET) and hydrogen-atom transfer (HAT) reactions, collectively called H-atom abstraction (HAA) reactions, play critical roles in biological processes and modern organic synthesis. The kinetics of these processes can align with the principles described in the renowned Marcus cross relation (MCR), a framework initially formulated to describe electron transfer mechanisms. The MCR provides an outstanding link between the kinetics of HAA reactions involving two distinct reactants and two related auxiliary self-exchange reactions—each between a molecule of one of the reactants and its conjugated radical. In this study, we investigate the applicability and limitations of the canonical MCR across over 300 HAA reactions, providing a comprehensive theoretical analysis. Our findings reveal the need for an enhanced framework that incorporates “off-diagonal” thermodynamic factors—asynchronicity and frustration. Of these factors, asynchronicity, which quantifies the imbalance between the proton vs electron transfer components of the reaction, is identified as the dominant contributor to the improved predictive accuracy of the MCR. Notably, the incorporation of off-diagonal thermodynamics yields a more pronounced enhancement for HAT reactions than for PCET-like HAA reactions. As a corollary, the model also describes a so-called pseudoinverted region, in which more exergonic reactions feature higher free energy barriers even though the thermodynamic driving force is not so large as it is required for the proper inverted region well-known from the original Marcus theory. This advancement offers a refined theoretical basis for understanding H-atom abstraction mechanisms and underscores the importance of off-diagonal effects in HAA chemistry.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Chemical Physics

ISSN

0021-9606

e-ISSN

1089-7690

Svazek periodika

163

Číslo periodika v rámci svazku

14

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

144105

Kód UT WoS článku

001591299000001

EID výsledku v databázi Scopus

2-s2.0-105018173913