Hydrophobic hydration in methanol aqueous solutions


Por: Hernández-Cobos J., Ortega-Blake I.

Publicada: 1 ene 1995
Resumen:
In this work we present a Monte Carlo study of a methanol-water mixture. The model potentials used includes polarization and nonadditive effects in the intermolecular interactions. The parameters were fitted to two- and three-body energy surfaces computed ab initio with a basis set of 2? plus polarization quality. Correlation was included at the MP2 level, and the basis set superposition error was corrected with the counterpoise method. Very long runs, 20×106 configurations, were used to assure that equilibrium was attained. Good agreement with experiment was found for the structural data; the carbon to water oxygen and the hydrogen to hydrogen radial distribution functions. We studied the hydrophobic hydration of the methyl group and the effect of the solute on the water structure. We found that there is hydration of the hydroxyl group and a caging of the methyl group; that the solute does indeed affect the water structure at close distance to the solute but that this effect is masked by the average over the whole system. The water structure is disrupted by a slight broadening of the first peak in the O-O rdf and a shift of the second peak toward larger distances, we have also found that there is some methanol-methanol association. © 1995 American Institute of Physics.

Filiaciones:
Hernández-Cobos J.:
 Institute de Física, Laboratorio de Cuernavaca, Universidad Nacional Autónoma de México, Apartado Postal 139-B, 62191 Cuernavaca, Morelos, Mexico

Ortega-Blake I.:
 Institute de Física, Laboratorio de Cuernavaca, Universidad Nacional Autónoma de México, Apartado Postal 139-B, 62191 Cuernavaca, Morelos, Mexico

 Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad s/n, Cuernavaca, Morelos, Mexico
ISSN: 00219606
Editorial
AMER INST PHYSICS, CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA, Estados Unidos America
Tipo de documento: Article
Volumen: 103 Número: 21
Páginas: 9261-9273
WOS Id: A1995TF80800015