@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 = {<Go to ISI>://000269252700016},
	author = {Koga,Yoshikata and Sebe, F. and Minami, T. and Otake, K. and Saitow, K. and Nishikawa, K.}
}
@article {2129,
	title = {Mixing schemes in a urea-H2O system: A differential approach in solution thermodynamics},
	journal = {Journal of Physical Chemistry B},
	volume = {112},
	number = {36},
	year = {2008},
	note = {ISI Document Delivery No.: 345EVTimes Cited: 5Cited Reference Count: 29Koga, Yoshikata Miyazaki, Yuji Nagano, Yatsuhisa Inaba, Akira},
	month = {Sep},
	pages = {11341-11346},
	type = {Article},
	abstract = {The excess partial molar enthalpies of urea (UR), H-UR(E), were experimentally determined in UR-H2O at 25 degrees C. The H-UR(E) data were determined accurately and in small increments in the mole fraction of UR, X-UR, up to X-UR approximate to 0.22. Hence it was possible to evaluate one more X-UR-derivative graphically Without resorting to any fitting function, and the model-fi-ee UR-UR enthalpic interaction, H{\textquoteright}U{\textquoteright}-R-uR, was calculated. Using previous data for the excess chemical potential, mu(E)(UR), the entropy analogue, S-UR(E)-UR. was also calculated. The X-UR-dependences of both H-UR(E)-UR and S-UR(E)-UR indicate that there is a boundary at X-UR approximate to 0.09 at which the aggregation nature of urea changes. Front the results of our earlier works, we suggest that a few UR molecules aggregate at X-UR approximate to 0.09, while the integrity of H2O is retained at least up to X-UR approximate to 0.20. Together with the findings from our previous studies, we suggest that in the concentration range X-UR < 0.22, UR or its aggregate form hydrogen bonds to the H2O network, reducing the degree of fluctuation characteristic to liquid H2O. However, up to at least X-UR = 0.20 the hydrogen bond network remains intact. Above X-UR approximate to 0.22, the integrity of H2O is likely be lost. Thus, in discussing the effect of urea on H2O and in relating it to the Structure and function of biopolymers in aqueous solutions, the concentration region in question must be specified.},
	keywords = {25-DEGREES-C, AQUEOUS UREA, DYNAMICS, ENTHALPIES, H2O, LIQUID WATER, MOLECULAR-ORGANIZATION, NUCLEAR-MAGNETIC-RESONANCE, POTASSIUM, WATER-STRUCTURE},
	isbn = {1520-6106},
	url = {<Go to ISI>://000258979800023},
	author = {Koga,Yoshikata and Miyazaki, Y. and Nagano, Y. and Inaba, A.}
}
@article {901,
	title = {Mixing schemes in ionic liquid-H2O systems: A thermodynamic study},
	journal = {Journal of Physical Chemistry B},
	volume = {108},
	number = {50},
	year = {2004},
	note = {ISI Document Delivery No.: 879CXTimes Cited: 78Cited Reference Count: 33},
	month = {Dec},
	pages = {19451-19457},
	type = {Article},
	abstract = {We studied the hydration characteristics of room-temperature ionic liquids (IL). We experimentally determined the excess chemical potentials, mu(i)(E), the excess partial molar enthalpies, H-i(E), and the excess partial molar entropies S-i(E) in IL-H2O systems at 25 degreesC. The ionic liquids studied were 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) and the iodide ([bmim]l). From these data, the excess (integral) molar enthalpy and entropy, H-m(E) and S-m(E), and the IL-IL enthalpic interaction, H-IL-IL(E), were calculated. Using these thermodynamic data, we deduced the mixing schemes, or the "solution structures", of IL-H2O systems. At infinite dilution IL dissociates in H2O, but the subsequent hydration is much weaker than for NaCl. As the concentration of IL increases, [bmim]l ions and the counteranions begin to attract each other up to a threshold mole fraction, x(IL) = 0.015 for [bmim]BF4 and 0.013 for [bmim]l. At still higher mole fractions, IL ions start to organize themselves, directly or in an H2O-Mediated manner. Eventually for x(IL) > 0.5-0.6, IL molecules form clusters of their own kind, as in their pure states. We show tha HI-L-IL, a third derivative of G, provided finer details than H-i(E) and S-i(E) second derivatives, which in turn gave more detailed information than H-m(E) and S-m(E), first derivative quantities.},
	keywords = {25-DEGREES-C, AQUEOUS SODIUM-CHLORIDE, ENTHALPIES, GLYCEROL, H2O, METHANOL, MIXTURES, MOLECULAR-ORGANIZATION, SOLVENTS, WATER},
	isbn = {1520-6106},
	url = {<Go to ISI>://000225695100058},
	author = {Katayanagi, H. and Nishikawa, K. and Shimozaki, H. and Miki, K. and Westh, P. and Koga,Yoshikata}
}
@article {709,
	title = {Excess chemical potentials and partial molar enthalpies in aqueous 1,2-and 1,3-propanediols at 25 degrees C},
	journal = {Journal of Solution Chemistry},
	volume = {32},
	number = {2},
	year = {2003},
	note = {ISI Document Delivery No.: 661CMTimes Cited: 4Cited Reference Count: 24},
	month = {Feb},
	pages = {137-153},
	type = {Article},
	abstract = {Excess chemical potentials and excess partial molar enthalpies of 1,2- and 1,3-propanediols ( abbreviated as 12P and 13P), mu(i)(E), and H-i(E) ( i = 12P or 13P) were determined in the respective binary aqueous solutions at 25degreesC. For both systems, the values of mu(i)(E) are almost zero, within +/-0.4 kJ-mol(-1). However, the excess partial molar enthalpies, H-i(E) show a sharp mole fraction dependence in the water-rich region. Thus, the systems are highly nonideal, in spite of almost zero mu(i)(E). Namely, the enthalpy-entropy compensation is almost complete. From the slopes of the HE i against the respective mole fraction x(i) we obtain the enthalpic interaction functions between solutes, H-i-i(E), ( i = 12P or 13P). Using these quantities and comparing them with the equivalent quantities for binary aqueous solutions of 1-propanol ( 1P), 2-propanol (2P), glycerol (Gly), and dimethyl sulfoxide ( DMSO), we conclude that there are three composition regions in each of which mixing schemes are qualitatively different. Mixing Schemes II and III, operative in the intermediate and the solute-rich regions, seem similar in all the binary aqueous solutions mentioned above. Mixing Scheme I in the water-rich region is different from solute to solute. 12P shows a behavior similar to that of DMSO, which is somewhat different from typical hydrophobic solute, 1P or 2P. 13P, on the other hand, is less hydrophobic than 12P, and shows a behavior closer to glycerol, which shows hydrophilic behavior.},
	keywords = {2-and 1, 3-propanediols, ALCOHOL, chemical potentials, ENERGIES, ENTHALPIES, ENTROPIES, H2O, interaction functions, MIXING SCHEMES, mixing schemes in aqueous 1, MOLECULAR-ORGANIZATION, NONELECTROLYTES, partial molar, TERT-BUTANOL MIXTURES, VOLUMES, WATER-RICH REGION},
	isbn = {0095-9782},
	url = {<Go to ISI>://000181873700003},
	author = {Parsons, M. T. and Lau, F. W. and Yee, E. G. M. and Koga,Yoshikata}
}
@article {656,
	title = {Excess partial molar entropy of alkane-mono-ols in aqueous solutions at 25 degrees C},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {81},
	number = {2},
	year = {2003},
	note = {ISI Document Delivery No.: 652JVTimes Cited: 9Cited Reference Count: 21},
	month = {Feb},
	pages = {150-155},
	type = {Article},
	abstract = {In the preceding paper, we reported the values of model-free chemical potentials for aqueous methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 1-hexanol at 25degreesC over the entire compositional region. Using alcohol excess partial molar enthalpies, H-AL(E), determined earlier in this laboratory (Can. J. Chem. 74, 713 (1996)), we have calculated excess partial molar entropies for the alcohols, S-AL(E), where AL stands for an alcohol. We then calculated, numerically, the entropic interaction, S-AL-AL(E) = N(partial derivativeS(AL)(E)/partial derivativen(AL))(p,T,nW), where n(AL) is the amount of AL, n(W) is the amount of H2O, and N is the total amount of solution. S-AL-AL(E) signifies the effect of addition of AL upon the entropic situation of existing AL in solution. Using these quantities, the mixing schemes in aqueous alcohols have been studied. The earlier conclusions, which used H-AL(E) and H-AL-AL(E) alone, are confirmed. Furthermore, the order of the relative hydrophobic nature of alcohols is established from the behaviour of S-AL-AL(E) and of H-AL-AL(E) as methanol < ethanol < 2-propanol < 1-propanol.},
	keywords = {2-BUTOXYETHANOL, ALCOHOL, aqueous alcohols, BUTANOL, ENTHALPIES, entropic interaction, excess partial molar entropies, hydrophobicity ranking, MIXING SCHEME, MIXING SCHEMES, MIXTURES, NONELECTROLYTES, TRANSITION, VOLUMES, WATER-RICH REGION},
	isbn = {0008-4042},
	url = {<Go to ISI>://000181376800004},
	author = {Koga,Yoshikata and Westh, P. and Nishikawa, K.}
}
@article {4679,
	title = {Compressibilities of aqueous tert-butanol in the water-rich region at 25 degrees C: Partial molar fluctuations and mixing schemes},
	journal = {Physical Chemistry Chemical Physics},
	volume = {1},
	number = {1},
	year = {1999},
	note = {ISI Document Delivery No.: 179VLTimes Cited: 18Cited Reference Count: 25},
	month = {Jan},
	pages = {121-126},
	type = {Article},
	abstract = {We measured the speeds of sound, u, and the densities, d, and, hence, determined the adiabatic compressibilities, kappa(S), of aqueous tert-butanol (TBA) at small increments in mole fraction of TBA, x(TBA). Existing data for heat capacity, C-p, and thermal expansivity, alpha(p), were used to convert kappa(S) to the isothermal compressibilities, kappa(T). Using these kappa(T) data, the normalized volume fluctuations, (V)Delta, and their composition derivative, the partial molar volume fluctuations of TBA, (V)Delta(TBA), (Y. Koga and P. Westh, Bull. Chem. Soc. Jpn., 1996, 69, 1505) were calculated. By using C-p data available in the literature we also calculated the normalized entropy fluctuations, (S)Delta, and the partial molar entropy fluctuations of TBA, (S)Delta(TBA). Furthermore, the density data at 15, 25 and 35 degrees C in the literature were used to evaluate the thermal expansivities, alpha(p), from which the normalized cross (entropy-volume) fluctuations, (SV)Delta, and the partial molar cross-fluctuations of TBA, (SV)Delta(TBA), were calculated. The composition dependence of these fluctuation functions were interpreted in the Light of the mixing schemes in aqueous solutions of TBA and other non-electrolytes and the transition between them (Y. Koga, J. Phys. Chem., 1996, 100, 5172).},
	keywords = {2-BUTOXYETHANOL, ALCOHOL, ENTHALPIES, ISOCHORIC HEAT-CAPACITIES, ISOTHERMAL COMPRESSIBILITIES, MIXTURES, NONELECTROLYTES, SOUND, TRANSITION, VOLUMES},
	isbn = {1463-9076},
	url = {<Go to ISI>://000079350200017},
	author = {Tamura, K. and Osaki, A. and Koga,Yoshikata}
}
@article {4422,
	title = {Intermolecular interactions in tert-butyl alcohol dimethyl sulfoxide H2O: Chemical potentials, partial molar entropies and volumes},
	journal = {Journal of Physical Chemistry B},
	volume = {102},
	number = {26},
	year = {1998},
	note = {ISI Document Delivery No.: ZY137Times Cited: 13Cited Reference Count: 28},
	month = {Jun},
	pages = {5182-5195},
	type = {Article},
	abstract = {The excess chemical potentials, the excess partial molar entropies, and the partial molar volumes in tert-butyl alcohol (TBA)-dimethyl sulfoxide (DMSO)-H2O mixtures were determined. These data, together with previously published excess partial molar enthalpies (Fluid Phase Equilib. 1997, 136, 207) were used to evaluate intermolecular interactions. The TBA-TBA and TBA-DMSO, and DMSO-DMSO interactions were found to be crucially dependent on the composition. The net interaction in terms of chemical potential is very intricate. For example, net interactions of DMSO with a hydrophobic moiety (represented here by TEA) change from attractive to repulsive as the composition changes. This suggests that general discussions of the affinity of DMSO for nonpolar groups (or surfaces) are meaningful only by specifying the composition region. The interactions in terms of enthalpy and entropy are an order of magnitude larger and strongly compensating. Anomalous changes in the enthalpic/entropic interactions and hence qualitative changes in the mixing scheme of the solution, previously described in respective binary TBA-H2O and DMSO-H2O systems, are also apparent in this ternary system. II was found that as the mole fraction, x(D), of DMSO (third component) increases, the transition in mixing scheme occurred at a progressively lower value of x(B). The behavior of partial molar volume indicated that as x(B) increases, the initial increase in the partial molar volume of H2O on increasing x(D), reminiscent to "iceberg formation", diminished. This suggests that existing TEA molecules already made their contribution to the "iceberg formation". The DMSO-DMSO interaction in terms of volume also showed that the transition occurred at a smaller value of x(D) than that for x(B) = 0. The boundary between the two mixing schemes in the present ternary mixture was a straight line in the x(D)-x(B) field, suggesting that the effect of TEA and DMSO on H2O, causing the transition in the mixing scheme, is additive.},
	keywords = {AQUEOUS-SOLUTIONS, ENTHALPIES, HYDROPHOBIC INTERACTION, MIXING SCHEME, MIXTURES, NONELECTROLYTES, NONPOLAR SOLUTE PARTICLES, PERCOLATION, TRANSITION, WATER-RICH REGION},
	isbn = {1089-5647},
	url = {<Go to ISI>://000074590000026},
	author = {Trandum, C. and Westh, P. and Haynes, C. A. and Koga,Yoshikata}
}
@article {3403,
	title = {Speeds of sound and isothermal compressibilities in the water-rich region of aqueous 2-butoxyethanol and 2-butanone at 25 degrees C},
	journal = {Journal of Solution Chemistry},
	volume = {24},
	number = {11},
	year = {1995},
	note = {ISI Document Delivery No.: TV702Times Cited: 8Cited Reference Count: 25},
	month = {Nov},
	pages = {1125-1133},
	type = {Article},
	abstract = {Speeds of sound were measured at 25 degrees C in the water-rich region of aqueous 2-butoxyethanol (BE) and 2-butanone (BUT). Density, heat capacity, and thermal expansivity data available in literature were used to calculate isothermal compressibilities, kappa(T). The composition derivative, N(partial derivative kappa(T)/partial derivative n(B)), a third derivative of Gibbs free energy, showed a peak anomaly at x(BE) = 0.0175 for BE-H2O, and bend at x(BUT) = 0.033 for BUT-H2O. n(B) (n(BE) or n(BUT)) is the amount of the solute and x(BE) and x(BUT) are the respective mole fractions. The location of these anomalies were the same as those of other third derivatives found earlier for the same aqueous solutions. These anomalies were shown earlier to mark the transition point across which the mixing scheme changes in a qualitative fashion.},
	keywords = {2-BUTANONE, 2-BUTOXYETHANOL, anomaly in the third derivative, aqueous solutions, ENTHALPIES, HEAT-CAPACITIES, isothermal compressibility, MIXING SCHEME, MIXTURES, of mixing scheme, PARTIAL MOLAR VOLUMES, RANGE, speed of sound, SYSTEMS, TRANSITION},
	isbn = {0095-9782},
	url = {<Go to ISI>://A1995TV70200004},
	author = {Koga,Yoshikata and Tamura, K. and Murakami, S.}
}
@article {3007,
	title = {EXCESS PARTIAL MOLAR VOLUMES AND THERMAL EXPANSIVITIES IN THE WATER-RICH REGION OF AQUEOUS 2-BUTANONE},
	journal = {Journal of Solution Chemistry},
	volume = {23},
	number = {2},
	year = {1994},
	note = {ISI Document Delivery No.: NB508Times Cited: 8Cited Reference Count: 22Symposium in Honor of Donald Patterson on His 65th Birthday, at the 76th Congress of the Canadian-Society-for-ChemistryMAY 31-JUN 03, 1993SHERBROOKE, CANADACANADIAN SOC CHEM},
	month = {Feb},
	pages = {339-349},
	type = {Proceedings Paper},
	abstract = {Excess partial molar volumes of 2-butanone V(m)E(B) and thermal expansivities alpha(p) were measured in the water-rich region of aqueous 2-butanone. The composition derivatives of both quantities showed anomalies at about X(B) = 0.033 (x(B) is the mole fraction of B). (partial derivative V(m)E(B)/partial derivative n(B))p,T,nW showed a step anomaly, while (partial derivative alpha(p)/partial derivatives n(B))p,T,nw exhibited a peak anomaly. The compositions at which these anomalies occurred match those of the step anomalies observed earlier in (partial derivative H(m)E(B)/partial derivative n(B))p,T,nW and (partial derivative S(m)E(B)/partial derivative n(B))p,T,nW in aqueous 2-butanone. These results are discussed in comparison with those obtained previously for aqueous 2-butoxyethanol.},
	keywords = {2-BUTANONE, 2-BUTOXYETHANOL, 25-DEGREES-C, ANOMALIES IN 3RD DERIVATIVES, AQUEOUS, DERIVATIVES, ENTHALPIES, EXCESS PARTIAL MOLAR VOLUMES, fluctuations, FREE-ENERGIES, HEAT-CAPACITIES, MIXING SCHEME, OF GIBBS FREE ENERGY, TERT-BUTANOL MIXTURES, THERMAL EXPANSIVITIES, TRANSITION, TRANSITION OF MIXING SCHEME},
	isbn = {0095-9782},
	url = {<Go to ISI>://A1994NB50800016},
	author = {Davies, J. V. and Fooks, R. and Koga,Yoshikata}
}
