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Predicting Solvent Effects on SN2 Reaction Rates: Comparison of QM/MM, Implicit, and MM Explicit Solvent Models.
Taylor, Mackenzie; Yu, Haibo; Ho, Junming.
Afiliación
  • Taylor M; School of Chemistry, The University of New South Wales, Sydney, New South Wales2052, Australia.
  • Yu H; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales2522, Australia.
  • Ho J; School of Chemistry, The University of New South Wales, Sydney, New South Wales2052, Australia.
J Phys Chem B ; 126(44): 9047-9058, 2022 11 10.
Article en En | MEDLINE | ID: mdl-36300819
Solvents are one of the key variables in the optimization of a synthesis yield or properties of a synthesis product. In this paper, contemporary solvent models are applied to predict the rates of SN2 reactions in a range of aqueous and non-aqueous solvents. High-level CCSD(T)/CBS//M06-2X/6-31+G(d) gas phase energies were combined with solvation free energies from SMD, SM12, and ADF-COSMO-RS continuum solvent models, as well as molecular mechanics (MM) explicit solvent models with different atomic charge schemes to predict the rate constants of three SN2 reactions in eight protic and aprotic solvents. It is revealed that the prediction of rate constants in organic solvents is not necessarily less challenging than in water and popular solvent models struggle to predict their rate constants to within 3 log units of experimental values. Among the continuum solvent models, the ADF-COSMO-RS model performed the best in predicting absolute rate contants while the SM12 model was best at predicting relative rate constants with an average accuracy of about 1.5 and 0.8 log units, respectively. The use of computationally more demanding MM explicit solvent models did not translate to improvements in absolute rate constants but was quite effective at predicting relative rate constants due to systematic error cancellation. Free energy barriers obtained from umbrella sampling with explicit solvent QM/MM simulations led to excellent agreement with experimental values, provided that a validated level of theory is used to treat the QM region.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Simulación de Dinámica Molecular Tipo de estudio: Prognostic_studies / Risk_factors_studies Idioma: En Revista: J Phys Chem B Asunto de la revista: QUIMICA Año: 2022 Tipo del documento: Article País de afiliación: Australia Pais de publicación: Estados Unidos
Texto completo
Añadir a Mi BVS
Imprimir
XML
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Simulación de Dinámica Molecular Tipo de estudio: Prognostic_studies / Risk_factors_studies Idioma: En Revista: J Phys Chem B Asunto de la revista: QUIMICA Año: 2022 Tipo del documento: Article País de afiliación: Australia Pais de publicación: Estados Unidos