@article {2474, title = {Spectrum of Excess Partial Molar Absorptivity. I. Near Infrared Spectroscopic Study of Aqueous Acetonitrile and Acetone}, journal = {Journal of Physical Chemistry B}, volume = {113}, number = {35}, year = {2009}, note = {ISI Document Delivery No.: 487EETimes Cited: 4Cited Reference Count: 22Koga, Yoshikata Sebe, Fumie Minami, Takamasa Otake, Keiko Saitow, Ken-ichi Nishikawa, Keiko}, month = {Sep}, pages = {11928-11935}, type = {Article}, abstract = {We study the mixing schemes or the molecular processes occurring in aqueous acetonitrile (ACN) and acetone (ACT) by near-infrared spectroscopy (NIR). Both solutions (any other aqueous solutions) are not free from strong and complex intermolecular interactions. To tackle such a many-body problem, we first use the concept of the excess molar absorptivity, epsilon(E), which is a function of solute mole fraction in addition to that of wavenumber, nu. The plots of F E calculated from NIR spectra for both aqueous solutions against nu showed two clearly separated bands at 5020 and 5230 cm(-1); the former showed negative and the latter positive peaks. At zero and unity mole fractions of solute, epsilon(E) is identically zero independent of v. Similar to the thermodynamic excess functions, both negative and positive bands grow in size from zero to the minimum (or the maximum) and back to zero, as the mole fraction varies from 0 to 1. Since the negative band{\textquoteright}s nu-locus coincides with the NIR spectrum of ice, and the positive with that of liquid H2O, we suggest that on addition of solute the "ice-likeness" decreases and the "liquid-likeness" increases, reminiscent of the two-mixture model for liquid H2O. The modes of these variations, however, are qualitatively different between ACN-H2O and ACT-H2O. The former ACN is known to,let as a hydrophobe and ACT as a hydrophile from Our previous thermodynamic studies. To see the difference more clearly, we introduced and calculated the excess partial molar absorptivity of ACN and ACT, epsilon(E)(N), and epsilon(E,)(T) respectively. The mole fraction dependences of epsilon(E)(N) and epsilon(E)(T) show qualitatively different behavior and are consistent with the detailed mixing schemes elucidated by our earlier differential thermodynamic studies. Furthermore, we found in the H2O-rich region that the effect of hydrophobic ACN is acted on the negative band at 5020 cm(-1), while that of hydrophilic ACT is on the positive high-energy band. Thus, the present method of analysis adds more detailed insight into the difference between a hydrophobe and a hydrophile in their effects on H2O.}, keywords = {2-DIMENSIONAL CORRELATION SPECTROSCOPY, 25-DEGREES-C, CHEMICAL-POTENTIALS, ENTHALPIES, ENTROPIES, HYDROGEN-BONDS, MIXTURES, NON-ELECTROLYTES, TEMPERATURE, WATER}, isbn = {1520-6106}, url = {://000269252700016}, author = {Koga,Yoshikata and Sebe, F. and Minami, T. and Otake, K. and Saitow, K. and Nishikawa, K.} } @article {1627, title = {Toward understanding the Hofmeister series. 3. Effects of sodium halides on the molecular organization of H2O as probed by 1-propanol}, journal = {Journal of Physical Chemistry A}, volume = {110}, number = {5}, year = {2006}, note = {ISI Document Delivery No.: 011VUTimes Cited: 15Cited Reference Count: 42}, month = {Feb}, pages = {2072-2078}, type = {Article}, abstract = {We investigated the effects of NaF, NaCl, NaBr, and NaI on the molecular organization of H2O by a calorimetric methodology developed by us earlier. We use the third derivative quantities of G pertaining to I-propanol (1P) in ternary 1P-asalt-H2O as a probe to elucidate the effects of a salt on H2O. We found that NaF and NaCl worked as hydration centers. The hydration numbers were 19 +/- 2 for NaF and 7.5 +/- 0.6 for NaCl. Furthermore, the bulk H2O away from the hydration shell was found unaffected by the presence of Na+, F-, and Cl-. For NaBr and NaI, in addition to the hydration to Na+, Br- and I- acted like a hydrophilic moiety such as urea. Namely, they formed a hydrogen bond to the existing H2O network and retarded the fluctuation nature of H2O. These findings were discussed with respect to the Hofmeister ranking. We suggested that more chaotropic anions Br- and I- are characterized as hydrophiles, whereas kosmotropes, F- and Cl-, are hydration centers.}, keywords = {25-DEGREES-C, AQUEOUS-SOLUTIONS, CHEMICAL-POTENTIALS, DIELECTRIC-SPECTROSCOPY, INTERMOLECULAR INTERACTIONS, LIQUID WATER, MIXING SCHEMES, NONELECTROLYTES, partial molar enthalpy, TERT-BUTYL ALCOHOL}, isbn = {1089-5639}, url = {://000235297400050}, author = {Westh, P. and Kato, H. and Nishikawa, K. and Koga,Yoshikata} } @article {655, title = {Effect of ethylene glycol on the molecular organization of H2O in comparison with methanol and glycerol: A calorimetric study}, journal = {Journal of Solution Chemistry}, volume = {32}, number = {9}, year = {2003}, note = {ISI Document Delivery No.: 742ZVTimes Cited: 8Cited Reference Count: 25}, month = {Sep}, pages = {803-818}, type = {Article}, abstract = {Excess partial molar enthalpies of ethylene glycol, H-EG(E), in binary ethylene glycol-H2O, and those of 1-propanol, H-IP(E), in ternary 1-propanol-ethylene glycol (or methanol)-H2O were determined at 25degreesC. From these data, the solute-solute interaction functions, H-EG-EG(E)=N(partial derivativeH(EG)(E)/partial derivativen(EG)) and H-1P-1P(E)=N(partial derivativeH(1P)(E)/partial derivativen(1P)), were calculated by graphical differentiation without resorting to curve fitting. Using these, together with the partial molar volume data, the effect of ethylene glycol on the molecular organization of H2O was investigated in comparison with methanol and glycerol. We found that there are three concentration regions, in each of which the mixing scheme is qualitatively different from the other regions. Mixing scheme III operative in the solute-rich region is such that the solute molecules are in a similar situation as in the pure state, most likely in clusters of its own kind. Mixing scheme II, in the intermediate region, consists of two kinds of clusters each rich in solute and in H2O, respectively. Thus, the bond percolation nature of the hydrogen bond network of liquid H2O is lost. Mixing scheme I is a progressive modification of liquid H2O by the solute, but the basic characteristics of liquid H2O are still retained. In particular, the bond percolation of the hydrogen bond network is still intact. Similar to glycerol, ethylene glycol participates in the hydrogen bond network of H2O via-OH groups, and reduces the global average of the hydrogen bond probability and the fluctuations inherent in liquid H2O. In contrast to glycerol, there is also a sign of a weak hydrophobic effect caused by ethylene glycol. However, how these hydrophobic and hydrophilic effects of ethylene glycol work together in modifying the molecular organization of H2O in mixing scheme I is yet to be elucidated.}, keywords = {25-DEGREES-C, ALKANE-MONO-OLS, AQUEOUS-SOLUTIONS, CHEMICAL-POTENTIALS, effect on the, enthalpic interaction, enthalpy, ethylene glycol-H2O, excess partial molar, methanol-, MIXING SCHEMES, molecular organization of H2O, or glycerol-H2O, PARTIAL MOLAR ENTHALPIES, TERT-BUTANOL MIXTURES, THERMODYNAMIC APPROACH, VOLUMES, WATER}, isbn = {0095-9782}, url = {://000186548700004}, author = {Koga,Yoshikata} } @article {476, title = {Interactions in 1-propanol-(1,2-and 1,3-)propanediol-H2O: The effect of hydrophobic vs hydrophilic moiety on the molecular organization of H2O}, journal = {Journal of Physical Chemistry B}, volume = {106}, number = {28}, year = {2002}, note = {ISI Document Delivery No.: 573UETimes Cited: 9Cited Reference Count: 24}, month = {Jul}, pages = {7090-7095}, type = {Article}, abstract = {The excess partial molar enthalpy and the excess chemical potential of 1-propanol in ternary systems 1-propanol-(1,2- and 1,3-)propanediols-H2O were determined. The enthalpic interaction function between 1-propanol molecules was evaluated. The mole fraction dependence of the 1-propanol-1-propanol interaction function was used as a probe to elucidate the effect of 1,2- and 1,3-propanediols on the molecular organization of H2O. Together with the earlier similar works on 2-propanol and glycerol, we conclude that the hydrophobic moiety diminishes the hydrogen bond connectivity of H2O by reducing the hydrogen bond probability of bulk H2O, while the effect of the hydropbilic moiety is primarily to reduce the degree of fluctuation inherent in liquid H2O.}, keywords = {25-DEGREES-C, AQUEOUS MIXTURES, CHEMICAL-POTENTIALS, MIXING SCHEMES, NON-ELECTROLYTES, NONELECTROLYTES, PARTIAL MOLAR ENTHALPIES, TERT-BUTANOL, VOLUMES, WATER-RICH REGION}, isbn = {1520-6106}, url = {://000176849000018}, author = {Parsons, M. T. and Koga,Yoshikata} } @article {5032, title = {Excess partial molar enthalpy of 1-propanol in 1-propanol-acetone (or tetramethyl urea)-H2O at 25 degrees C: effect of acetone (or tetramethyl urea) on H2O}, journal = {Fluid Phase Equilibria}, volume = {189}, number = {1-2}, year = {2001}, note = {ISI Document Delivery No.: 495HBTimes Cited: 6Cited Reference Count: 11}, month = {Oct}, pages = {31-38}, type = {Article}, abstract = {Excess partial molar enthalpies of 1-propanol, H-1P(E), were measured at 25 degreesC in ternary 1-propanol-acetone (or tetramethyl urea)-H2O, with various initial compositions of acetone (or tetramethyl urea). They were determined accurately and in small increments in mole fraction of 1-propanol. It was therefore, possible to take a derivative of H-1P(E) with respect to the amount of 1-propanol, n(1P), H-1P-1P(E) = N (partial derivativeH(1P)(E)/partial derivativen(1P)). The changes in the mole fraction dependence of H-1P(E) and hence, H-1P-1P(E) caused by adding a third component, acetone or tetramethyl urea, were compared with the results of analogous earlier studies with urea and 2-propanol as a third component. The effects of acetone and tetramethyl urea were found qualitatively the same. The CH3- group in each compound works as a typical hydrophobic moiety and enhances the hydrogen bond network of H2O in the immediate vicinity of solute molecule ("iceberg formation") with concomitant reduction of the hydrogen bond probability of H2O. The C=O group on the other hand, seems to reduce the degree of fluctuation in the hydrogen bond strength in the bulk H2O away from the solute. (C) 2001 Elsevier Science B.V. All rights reserved.}, keywords = {1-PROPANOL, 1-propanol-1-propanol enthalpic interaction, 1-propanol-acetone (or tetramethyl urea)-H2O, acetone or tetramethyl urea on H2O, CHEMICAL-POTENTIALS, effect of, ENTROPIES, fluctuations, partial molar enthalpy of, TERT-BUTANOL}, isbn = {0378-3812}, url = {://000172333200003}, author = {Chen, D. H. C. and Liu, A. P. C. and Koga,Yoshikata} } @article {5159, title = {A thermodynamic study of 1-propanol-glycerol-H2O at 25 degrees C: Effect of glycerol on molecular organization of H2O}, journal = {Journal of Solution Chemistry}, volume = {30}, number = {11}, year = {2001}, note = {ISI Document Delivery No.: 514HPTimes Cited: 29Cited Reference Count: 36}, month = {Nov}, pages = {1007-1028}, type = {Article}, abstract = {The excess chemical potential, partial molar enthalpy, and volume of 1-propanol were determined in ternary mixtures of 1-propanol-glycerol-H2O at 25degreesC. The mole fraction dependence of all these thermodynamic functions was used to elucidate the effect of glycerol on the molecular organization of H2O. The glycerol molecules do not exert a hydrophobic effect on H2O. Rather, the hydroxyl groups of glycerol, perhaps by forming clusters via its alkyl backbone with hydroxyl groups pointing outward, interact with H2O so as to reduce the characteristics of liquid H2O. The global hydrogen bond probability and, hence, the percolation nature of the hydrogen bond network is reduced. In addition, the degree of fluctuation inherent in liquid H2O is reduced by glycerol perhaps by participating in the hydrogen bond network via OH groups. At infinite dilution, the pair interaction coefficients in enthalpy were evaluated and these data suggest a possibility that the interaction is mediated through H2O.}, keywords = {1-propanol-glycerol-H2O, AQUEOUS-SOLUTIONS, CHEMICAL-POTENTIALS, effect of glycerol on H2O, enthalpy of 1-propanol, ENTROPIES, excess chemical potential, fluctuations, interactions, INTERMOLECULAR, INTERMOLECULAR INTERACTIONS, MIXING SCHEMES, partial molar, PARTIAL MOLAR ENTHALPIES, partial molar volume of 1-propanol, TERT-BUTANOL, VOLUMES, WATER}, isbn = {0095-9782}, url = {://000173433400005}, author = {Parsons, M. T. and Westh, P. and Davies, J. V. and Trandum, C. and To, E. C. H. and Chiang, W. M. and Yee, E. G. M. and Koga,Yoshikata} } @article {4958, title = {Interactions in D-fructose-1-propanol-H2O: the effect of D-fructose on the molecular organization of liquid H2O}, journal = {Fluid Phase Equilibria}, volume = {171}, number = {1-2}, year = {2000}, note = {ISI Document Delivery No.: 349EQTimes Cited: 5Cited Reference Count: 27}, month = {May}, pages = {151-164}, type = {Article}, abstract = {Densities of binary aqueous solutions of D-fructose (abbreviated as FR hereinafter) were determined in a much wider mole fraction range than available in literature. In contrast to hydrophobic solutes, the partial molar volume of FR, V-FR, does not show an initial decrease on increasing the mole fraction of FR, x(FR). In order to learn more about the effect of FR on the molecular organization of liquid H2O, the excess chemical potentials and partial molar enthalpy of 1-propanol (1P) were determined in ternary 1P-FR-H2O system. Namely, the detailed thermodynamic behaviour of 1P in the ternary system was used as a probe to elucidate the effect of FR on liquid H2O. In comparison with earlier results of the temperature dependence of tert-butanol (TBA)-TBA interaction functions, addition of FR seems to have a similar effect of temperature increase on the molecular organization of H2O. We suggest that addition of FR tends to decrease the global average of hydrogen bond probability of H2O. (C) 2000 Elsevier Science B.V. All rights reserved.}, keywords = {25-DEGREES-C, AQUEOUS-SOLUTIONS, BUTYL ALCOHOL-SOLUTIONS, chemical potential, CHEMICAL-POTENTIALS, D-fructose-1-propanol-H2O, effect of beta-D-fructose on H2O, INTERMOLECULAR INTERACTIONS, MIXING SCHEME, PARTIAL MOLAR ENTHALPIES, partial molar enthalpy, TRANSITION, VOLUME, VOLUMES, WATER-RICH REGION}, isbn = {0378-3812}, url = {://000089031000011}, author = {To, E. C. H. and Westh, P. and Trandum, C. and Hvidt, A. and Koga,Yoshikata} } @article {3518, title = {A CONFIGURATION BIAS MONTE-CARLO METHOD FOR WATER}, journal = {Journal of Chemical Physics}, volume = {102}, number = {19}, year = {1995}, note = {ISI Document Delivery No.: QX773Times Cited: 29Cited Reference Count: 24}, month = {May}, pages = {7656-7663}, type = {Article}, keywords = {CANONICAL ENSEMBLE, CHAIN MOLECULES, CHEMICAL-POTENTIALS, DYNAMICS, SIMULATION}, isbn = {0021-9606}, url = {://A1995QX77300041}, author = {Shelley, J. C. and Patey, G. N.} }