Isotopic Preferential Solvation of I– in Low-Temperature Water Nanoclusters
| Autor: | Peter J. Rossky, Pablo E. Videla, Daniel Laria |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Aqueous solution
Hydrogen bond Chemistry Otras Ciencias Químicas Equilibrio Isotopico Ciencias Químicas Solvation Halide Nanoagregados Surfaces Coatings and Films Nanoclusters Ion Solvation shell Solvatacion Integrals de Camino Materials Chemistry Molecule Physical chemistry Physical and Theoretical Chemistry CIENCIAS NATURALES Y EXACTAS |
| Zdroj: | The Journal of Physical Chemistry B. 119:11783-11790 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/acs.jpcb.5b05561 |
| Popis: | We present results from ring polymer molecular dynamics experiments that provide microscopic insights into the characteristics of the isotopic stabilizations of H and D aqueous species in the first solvation shell of a halide I- ion in water nanoclusters at low temperatures. The analysis of the simplest I-·(HOD) dimer shows a clear propensity for the light isotope to lie at the non-hydrogen-bonded dangling position. Our results predict that, at T ∼ 50 K, I-·(DOH) isomers are three times more abundant than I-·(HOD) ones. The reasons for such stabilization can be traced back to differences in the nuclear kinetic energy projected along directions perpendicular to the plane of the water molecule. Dynamical implications of these imbalances are shown to be reflected in the characteristics of the corresponding bands of the infrared spectroscopic signals. A similar analysis performed in larger aggregates containing ∼20 water molecules reveals, in contrast, a stabilization of the light isotope along I-⋯HO hydrogen bonds. Effects derived from the consideration of smaller halide anions with larger electric fields at the surface are also examined. (Figure Presented). Fil: Videla, Pablo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina Fil: Rossky, Peter J.. Rice University; Estados Unidos Fil: Laria, Daniel Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Comisión Nacional de Energía Atómica; Argentina |
| Databáze: | OpenAIRE |
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