A 3D-RISM-SCF method with dual solvent boxes for a highly polarized system: application to 1,6-anhydrosugar formation reaction of phenyl α- and β-D-glucosides under basic conditions
| Autor: | Shinji Aono, Shigeyoshi Sakaki, Takashi Hosoya |
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| Rok vydání: | 2013 |
| Předmět: |
Field (physics)
Levoglucosan Solvation General Physics and Astronomy Function (mathematics) Hydrogen-Ion Concentration Solvent chemistry.chemical_compound Solvation shell Glucose chemistry Glucosides Chemical physics Computational chemistry Solvents Quantum Theory Reactivity (chemistry) Physical and Theoretical Chemistry Wave function |
| Zdroj: | Physical chemistry chemical physics : PCCP. 15(17) |
| ISSN: | 1463-9084 |
| Popis: | One of the difficulties in application of the usual reference interaction site model self-consistent field (RISM-SCF) method to a highly polarized and bulky system arises from the approximate evaluation of electrostatic potential (ESP) with pure point charges. To improve this ESP evaluation, the ESP near a solute is directly calculated with a solute electronic wavefunction, that distant from a solute is approximately calculated with solute point charges, and they are connected with a switching function. To evaluate the fine solvation structure near the solute by incorporating the long-range solute-solvent Coulombic interaction with low computational cost, we introduced the dual solvent box protocol; one small box with the fine spacing is employed for the first and the second solvation shells and the other large box with the normal spacing is employed for long-range solute-solvent interaction. The levoglucosan formation from phenyl α- and β-d-glucosides under basic conditions is successfully inspected by this 3D-RISM-SCF method at the MP2 and SCS-MP2 levels, though the 1D-RISM-SCF could not be applied to this reaction due to the presence of highly polarized and bulky species. This 3D-RISM-SCF calculation reproduces the experimentally reported higher reactivity of the β-anomer. The 3D-RISM-SCF-calculated activation free energy for the β-anomer is closer to the experimental value than the PCM-calculated one. Interestingly, the solvation effect increases the difference in reactivity between these two anomers. The reason is successfully elucidated with 3D-RISM-SCF-calculated microscopic solvation structure and decomposition analysis of solute-solvent interaction. |
| Databáze: | OpenAIRE |
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