TY - JOUR
T1 - Monte Carlo simulations of an isolated N-octadecane chain solvated in water-acetonitrile mixtures
AU - Sun, Li
AU - Siepmann, J. Ilja
AU - Schure, Mark R.
PY - 2007/3
Y1 - 2007/3
N2 - To investigate conformational properties of an isolated n-octadecane chain solvated in water-acetonitrile mixtures, configurational-bias Monte Carlo simulations in the isobaric-isothermal ensemble were performed at T = 323 K and p = 10 atm. The united-atom version of the transferable potentials for phase equilibria force field was used to represent n-octadecane and acetonitrile, and the TIP-4P model was used for water. In all four environments (neat water, 33 and 67 mole percent acetonitrile, and neat acetonitrile), similar conformational distributions are observed as in a previous study for water-methanol solvent mixtures; that is, the n-octadecane chain is found to predominantly adopt extended but not all-trans conformations, and only a small fraction of more collapsed conformations is observed for aqueous hydration, water-rich solvent environments. Analysis of the local solvation structures in the water-acetonitrile mixtures shows an enrichment of the acetonitrile molecules near the methylene and methyl segments of the n-octadecane chain. However, upon increasing the concentration of acetonitrile, the enhancement of acetonitrile and the depletion of water is more pronounced than for water-methanol mixtures because of the weaker interactions between acetonitrile and water.
AB - To investigate conformational properties of an isolated n-octadecane chain solvated in water-acetonitrile mixtures, configurational-bias Monte Carlo simulations in the isobaric-isothermal ensemble were performed at T = 323 K and p = 10 atm. The united-atom version of the transferable potentials for phase equilibria force field was used to represent n-octadecane and acetonitrile, and the TIP-4P model was used for water. In all four environments (neat water, 33 and 67 mole percent acetonitrile, and neat acetonitrile), similar conformational distributions are observed as in a previous study for water-methanol solvent mixtures; that is, the n-octadecane chain is found to predominantly adopt extended but not all-trans conformations, and only a small fraction of more collapsed conformations is observed for aqueous hydration, water-rich solvent environments. Analysis of the local solvation structures in the water-acetonitrile mixtures shows an enrichment of the acetonitrile molecules near the methylene and methyl segments of the n-octadecane chain. However, upon increasing the concentration of acetonitrile, the enhancement of acetonitrile and the depletion of water is more pronounced than for water-methanol mixtures because of the weaker interactions between acetonitrile and water.
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U2 - 10.1021/ct600239z
DO - 10.1021/ct600239z
M3 - Article
AN - SCOPUS:36148937515
SN - 1549-9618
VL - 3
SP - 350
EP - 357
JO - Journal of Chemical Theory and Computation
JF - Journal of Chemical Theory and Computation
IS - 2
ER -