Microhydration of the Selenite Dianion: A Theoretical Study of Structures, Hydration Energies, and Electronic Stabilities of SeO32−(H2O)n (n = 0−6, 9) Clusters
| Autor: | Henryk Wicke, Artur Meleshyn |
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| Rok vydání: | 2010 |
| Předmět: |
Aqueous solution
Chemistry Hydrogen bond Binding energy Water chemistry.chemical_element Electrons Hydrogen Bonding Bond length Crystallography Sodium Selenite Computational chemistry Quantum Theory Thermodynamics Molecule Density functional theory Physical and Theoretical Chemistry Perturbation theory Selenium |
| Zdroj: | The Journal of Physical Chemistry A. 114:8948-8960 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp9120904 |
| Popis: | In extension of the ongoing investigations of oxyanion-water clusters, we studied energetically low-lying configurations of hydrated selenite dianion (and in select cases, SeO(3)(-)) clusters using density functional theory (B3LYP, M05-2X, PBE0) and second-order Møller-Plesset perturbation theory (MP2). Water molecules doubly hydrogen bond to the selenite oxygens for nor= 3 and increasingly form singly hydrogen bonds with selenite oxygens upon an increase of the cluster size as water-water interactions gain relative importance as compared to the selenite-water interactions. The calculated average Se-O bond length of 1.69-1.71 A and selenite tetrahedron height of 0.64-0.73 A are in accordance with recent experimental results for selenite in aqueous solution or adsorbed on calcite. Structural perturbations due to the hydration are accompanied by a considerable charge transfer (up to 0.55|e|) from the selenite substructure to the water molecules. Furthermore, the calculated electron binding energies evidence that selenite-water clusters are electronically stable only for nor= 4 (according to M05-2X) or nor= 5 (according to B3LYP and PBE0). The hitherto unknown hydration free energy of selenite was calculated using a cluster/continuum approach to fall into the range from -224.6 to -245.5 kcal/mol depending on the applied continuum solvation model. |
| Databáze: | OpenAIRE |
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