کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5410476 | 1506557 | 2016 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular dynamics simulations of K+-Clâ ion pair in polar mixtures of acetone and water: Preferential solvation and structural studies
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Molecular dynamics simulation studies have been performed for a series of polar mixtures of acetone and water containing a K+-Clâ ion pair. We have obtained the potentials of mean force (PMFs) for 15 mixtures spanning the whole composition range from 0% to 100% acetone. The PMFs indicate the presence of a stable contact ion pair (CIP), a solvent assisted ion pair (SAIP) and a solvent separated ion pair (SSIP) in all the compositions with acetone mole fraction (xacetone) â¤Â 0.50. However, for xacetone > 0.50 and xacetone â¤Â 0.90, PMFs suggest the presence of only a stable CIP and SAIP. For xacetone > 0.90, PMFs show the existence of only a stable CIP. While the stability of CIPs in mixtures increases with xacetone, the reverse trend is observed for SAIPs. The determination of thermodynamic properties suggests that entropy favours the CIPs and SAIPs in all the mixtures. The analysis of radial distribution functions using Kirkwood-Buff (KB) integrals explains the preferential solvation of the ion pair. We observed that in all the mixtures, K+-Clâ ion pair is preferentially solvated by water. Running coordination numbers of solvent molecules around the ion pair and preferential binding parameters also support the above observations. The dynamical aspects have been explored by calculating self-diffusion constants and hydrogen bond dynamics.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Liquids - Volume 213, January 2016, Pages 276-288
Journal: Journal of Molecular Liquids - Volume 213, January 2016, Pages 276-288
نویسندگان
Asrar A. Siddique, Bhalachandra L. Tembe,