RT Journal Article
T1 Molecular dynamics simulation of the structure and dynamics of water–1-Alkyl-3-methylimidazolium ionic liquid mixtures
A1 Méndez-Morales, Trinidad
A1 Carrete Montaña, Jesús
A1 Cabeza Gras, Oscar
A1 Gallego del Hoyo, Luis Javier
A1 Varela Cabo, Luis Miguel
K1 Cations
K1 Cations
K1 Hydrophobicity
K1 Mixtures
K1 Molecules
AB We have performed extensive molecular dynamic simulations to analyze the influence of cation and anion natures, and of water concentration, on the structure and dynamics of water–1-alkyl-3-methylimidazolium ionic liquid mixtures. The dependence on water concentration of the radial distribution functions, coordination numbers, and hydrogen bonding degree between the different species has been systematically analyzed for different lengths of the cation alkyl chain (alkyl = ethyl, butyl, hexyl, and octyl) and several counterions. These include two halogens of different sizes and positions in Hoffmeister series, Cl– and Br–, and the highly hydrophobic inorganic anion PF6– throughout its whole solubility regime. The formation of water clusters in the mixture has been verified, and the influences of both anion hydrophobicity and cation chain length on the structure and size of these clusters have been analyzed. The water cluster size is shown to be relatively independent of the cation chain length, but strongly dependent on the hydrophobicity of the anion, which also determines critically the network formation of water and therefore the miscibility of the ionic liquid. The greater influence of the anion relative to the cation one is seen to be reflected in all the analyzed physical properties. Finally, single-particle dynamics in IL–water mixtures is considered, obtaining the self-diffusion coefficients and the velocity autocorrelation functions of water molecules in the mixture, and analyzing the effect of cation, anion, and water concentration on the duration of the ballistic regime and on the time of transition to the diffusive regime. Complex non-Markovian behavior was detected at intermediate times within an interval progressively shorter as water concentration increases
PB American Chemical Society
SN 1520-6106
YR 2011
FD 2011-06-02
LK https://hdl.handle.net/10347/46181
UL https://hdl.handle.net/10347/46181
LA eng
NO J. Phys. Chem. B 2011, 115, 21, 6995–7008
NO This document is the Accepted Manuscript version of a Published Article that appeared in final form in The Journal of Physical Chemistry B, copyright © 2011 American Chemical Society. To access the final published article, see ACS Articles on Request
NO The authors wish to thank the financial support of Spanish “Ministerio de Educación y Ciencia” under the research projects FIS2007-66823-C02-0, FIS2007-66823-C02-02, and FIS2008-04894/FIS and also the funding of Xunta de Galicia through the research projects of references 10-PXI-103-294 PR and 10-PXIB-206-294 PR. Morever, this work has been funded by the Directorate General for R+D+i of the Xunta de Galicia (INCITE09E2R206033ES). All of these research projects are partially supported by FEDER funds. J. Carrete and T. Méndez-Morales thank the Spanish ministry of Education for their FPU grants
DS Minerva
RD 24 may 2026