The prototype binuclear elimination (E2) reaction illustrates the mechanism of a large number of biochemical and industrial applied processes but has received surprisingly little attention in theoretical studies compared to, for example, the substitution (SN2) reaction. This is due to its concerted mechanism, which requires an independent description of the three bonds that are being formed or broken. In this work, we have taken the advantage of a new and promising methodology to efficiently sample intrinsically multidimensional free-energy surfaces. We locate the lowest free-energy reaction path in the 3D configurational space and use this finite-temperature intrinsic reaction coordinate in an umbrella sampling scheme to access the temperature contributions to high accuracy. The small increase of the barrier and the decrease of the overall endothermicity for the E2 reaction due to entropic contributions is non-trivial. Moreover, our strategy to efficiently handle multiple reaction coordinates could be a great benefit to many chemistry-related fields, such as enzyme catalysis, reactions in solution, and nucleation processes.

A minimum free energy reaction path for the E2 reaction between fluoro ethane and a fluoride ion / Ensing, B.; Laio, A.; Gervasio, F. L.; Parrinello, M.; Klein, M. L.. - In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. - ISSN 0002-7863. - 126:31(2004), pp. 9492-9493. [10.1021/ja048285t]

A minimum free energy reaction path for the E2 reaction between fluoro ethane and a fluoride ion

Laio, A.;
2004-01-01

Abstract

The prototype binuclear elimination (E2) reaction illustrates the mechanism of a large number of biochemical and industrial applied processes but has received surprisingly little attention in theoretical studies compared to, for example, the substitution (SN2) reaction. This is due to its concerted mechanism, which requires an independent description of the three bonds that are being formed or broken. In this work, we have taken the advantage of a new and promising methodology to efficiently sample intrinsically multidimensional free-energy surfaces. We locate the lowest free-energy reaction path in the 3D configurational space and use this finite-temperature intrinsic reaction coordinate in an umbrella sampling scheme to access the temperature contributions to high accuracy. The small increase of the barrier and the decrease of the overall endothermicity for the E2 reaction due to entropic contributions is non-trivial. Moreover, our strategy to efficiently handle multiple reaction coordinates could be a great benefit to many chemistry-related fields, such as enzyme catalysis, reactions in solution, and nucleation processes.
2004
126
31
9492
9493
Ensing, B.; Laio, A.; Gervasio, F. L.; Parrinello, M.; Klein, M. L.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/11323
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