Analysis of Cooperativity and Group Additivity in the Hydration of 1,2-Dimethoxyethane
| Autor: | Sowmi Utiramerur, Michael E. Paulaitis |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
education.field_of_study
010304 chemical physics Population Ether Cooperativity 010402 general chemistry 01 natural sciences Decomposition Dimethoxyethane 0104 chemical sciences Surfaces Coatings and Films chemistry.chemical_compound chemistry Computational chemistry Additive function 0103 physical sciences Materials Chemistry Dimethyl ether Physical and Theoretical Chemistry Methylene education |
| Zdroj: | The Journal of Physical Chemistry B. 125:1660-1666 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/acs.jpcb.0c10729 |
| Popis: | We calculate hydration free energies of 1,2-dimethoxyethane (DME) conformations in water at 298 K and 1 bar. We find that the preference for the two most abundant tgt and tgg conformations derives from favorable nonspecific (i.e., long-range) solute-water interactions that are partially offset by unfavorable free energies of forming cavities in water to accommodate these conformations. The much lower population of the third most abundant tg+g- conformation, the most abundant conformation in the ideal gas at 298 K, is attributed to less favorable long-range solute-water interactions. We also find that long-range methyl/methylene group-water and ether oxygen-water interactions make significant nonadditive contributions to the free energy of DME hydration and propose a method based on quasichemical theory for reducing these nonadditive contributions by identifying constituent groups of DME that minimize the covariance in the long-range methyl/methylene group-water and ether oxygen-water interactions. We apply this method to show that the decomposition of DME into its constituent dimethyl ether groups is a better approximation of group additivity than decompositions based on distinguishing hydrophobic/hydrophilic constituent groups. |
| Databáze: | OpenAIRE |
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