@article {1202, title = {Effect of an "ionic liquid" cation, 1-butyl-3-methylimidazolium, on the molecular organization of H2O}, journal = {Journal of Physical Chemistry B}, volume = {109}, number = {18}, year = {2005}, note = {ISI Document Delivery No.: 924MMTimes Cited: 46Cited Reference Count: 46}, month = {May}, pages = {9014-9019}, type = {Article}, abstract = {The excess partial molar enthalpy of 1-propanol (1P), H-1P(E), was measured at 28 \° C in the ternary mixture of 1P-1-butyl-3-methylimidazolium chloride ([bmim]Cl)-H2O in the H2O-rich composition range. From these data we evaluated what we call the 1P-1P enthalpic interaction function, H-1P-1P(E). Its changes induced by addition of (bmim]Cl of the pattern of H-1P-1P(E) were used as a probe to elucidate the effect of [bmim]Cl on the molecular organization of H2O. It was found that the effect of Cl- was not conspicuous within this methodology, and the observed dependence is predominantly due to the hydration of [bmim](+). The changes in the \χ(1P)-dependence of H-1P-1P(E) were compared with those brought about by temperature increase, or by the addition of fructose or glycerol. It was found that the effect of [bmim](+) is similar to that of fructose or increased temperature. We speculate that in the H2O-rich composition region a number of H2O molecules are attracted to the delocalized positive charge of the imidazolium ring and the bulk of H2O is influenced in such a manner that the global hydrogen bond probability is reduced.}, keywords = {25-DEGREES-C, ALKANE-MONO-OLS, AQUEOUS-SOLUTIONS, fluctuations, HEXAFLUOROPHOSPHATE, MIXING SCHEMES, PARTIAL MOLAR ENTHALPIES, SOLVENTS, TERT-BUTANOL MIXTURES, WATER SOLUTIONS}, isbn = {1520-6106}, url = {://000228982900071}, author = {Miki, K. and Westh, P. and Nishikawa, K. and Koga,Yoshikata} }