@article {2460,
	title = {Hydrophobicity/Hydrophilicity of 1-Butyl-2,3-dimethyl and 1-Ethyl-3-methylimodazolium Ions: Toward Characterization of Room Temperature Ionic Liquids},
	journal = {Journal of Physical Chemistry B},
	volume = {113},
	number = {44},
	year = {2009},
	note = {ISI Document Delivery No.: 510QMTimes Cited: 2Cited Reference Count: 52Kato, Hitoshi Miki, Kumiko Mukai, Tomohiro Nishikawa, Keiko Koga, Yoshikata},
	month = {Nov},
	pages = {14754-14760},
	type = {Article},
	abstract = {We continue to experimentally characterize the constituent ions of room temperature ionic liquids in terms of their interactions with H2O. By using the so-called 1-propanol probing methodology, we experimentally index the relative hydrophobicity/hydrophilicity of a test ion. In this paper, we examine 1-butyl-2,3 dimethylimidazolium (abbreviated as [C(4)C(1)mim](+)) and 1-ethyl-3-methylimidazolium ([C(2)mim](+)). We found that [C(4)C(1)mim](+) dissociates completely in dilute aqueous solution less than 0.006 mol fraction, and hence, its hydrophobicity/hydrophilicity could be determined. The results indicate that [C(4)C(1)mim](+) is highly amphiphilic with much stronger hydrophobicity and hydrophilicity than normal ions. Our earlier similar studies indicated the same conclusion for such typical constituent ions as 1-butyl-3-methylimidazolium ([C(4)mim](+)) PF6-, CF3SO3-, and N(SO2CF3)(2)(-). Hence, we suggest that the constituent ions of room temperature ionic liquids that we have studied so far are all amphiphiles with much stronger hydrophobicity and hydrophilicity than normal ions. We found, furthermore, that the hydrophobicity and hydrophilicity of [C(4)C(1)mim](+) are stronger than those for [C(4)mim](+). A possible reason for higher hydrpohilicity is discussed in terms of strong acidic character of H on the C(2) of the imidazolium ring, which tends to attract the delocalized positive charge toward itself oil forming a hydrogen bond to H2O. On replacing it with CH3 in [C(4)C(1)mim](+), the lack of acidic H enhances the positive charge in the vicinity of N-C-N in the ring that interacts with the surrounding H2O strongly to an induced dipole of O of the H2O. For [C(2)mim](+), we found it does not dissociate completely, even in dilute aqueous solution, and hence, we could not characterize it within the present methodology.},
	keywords = {1-BUTYL-3-METHYLIMIDAZOLIUM BROMIDE, AGGREGATION BEHAVIOR, ALKYL CHAIN-LENGTH, APPROACH, AQUEOUS-SOLUTIONS, HOFMEISTER SERIES, MIXING SCHEMES, MOLECULAR-ORGANIZATION, partial molar enthalpy, PHYSICOCHEMICAL PROPERTIES, THERMODYNAMIC},
	isbn = {1520-6106},
	url = {<Go to ISI>://000271105600027},
	author = {Kato, H. and Miki, K. and Mukai, T. and Nishikawa, K. and Koga,Yoshikata}
}
@article {2123,
	title = {Chemical Potentials in Aqueous Solutions of Some Ionic Liquids with the 1-Ethyl-3-methylimidazolium Cation},
	journal = {Journal of Physical Chemistry B},
	volume = {112},
	number = {42},
	year = {2008},
	note = {ISI Document Delivery No.: 361AWTimes Cited: 3Cited Reference Count: 33Kato, Hitoshi Nishikawa, Keiko Murai, Hiromi Morita, Takeshi Koga, Yoshikata},
	month = {Oct},
	pages = {13344-13348},
	type = {Article},
	abstract = {We determined the vapor pressures of aqueous solutions of 1-ethyl-3-methylimidazolium ([C(2)mim])-based ionic liquids (IL) with counteranions, tetrafluoroborate (BF4-), trifluoromethanesulfonate (OTF-), and iodide (I-) Because in literature the evidence is accumulating and pointing to the fact that ionic liquid ions do not dissociate in aqueous media for the most of the concentration range, we analyzed the vapor pressure data on the basis of binary mixture, and the excess chemical potentials of each component were calculated. From these, the intermolecular interactions in terms of excess chemical potential and hence the concentration fluctuations were evaluated. Though any further discussion into the mixing schemes of the mixture awaits the excess partial molar enthalpy and hence the excess partial molar entropy data, the net interaction in terms of excess chemical potential indicates that the affinity of each IL is ranked in the descending order [C2mim]l > [C(2)mim]OTF > [C(2)mim]BF4. This is consistent with our earlier findings that [C(2)mim](+) is modestly amphiphilic with almost equal hydrophobicity and hydrophilicity, I- is a hydrophile, and OTF- is amphiphilic, and BF4- is believed to be strongly hydrophobic.},
	keywords = {1-BUTYL-3-METHYLIMIDAZOLIUM, ACETONITRILE, AGGREGATION BEHAVIOR, ENTHALPY-ENTROPY COMPENSATION, MIXING SCHEMES, MOLECULAR-ORGANIZATION, SYSTEMS, TETRAFLUOROBORATE, TETRAFLUOROBORATE PLUS WATER, THERMODYNAMIC APPROACH, VAPOR-PRESSURE MEASUREMENT},
	isbn = {1520-6106},
	url = {<Go to ISI>://000260100900026},
	author = {Kato, H. and Nishikawa, K. and Murai, H. and Morita, T. and Koga,Yoshikata}
}
@article {1440,
	title = {The effects of chloride salts of some cations on the molecular organization of H2O. Towards understanding the Hofmeister series. II},
	journal = {Bulletin of the Chemical Society of Japan},
	volume = {79},
	number = {9},
	year = {2006},
	note = {ISI Document Delivery No.: 097WCTimes Cited: 7Cited Reference Count: 42Koga, Yoshikata Katayanagi, Hideki Davies, James V. Kato, Hitoshi Nishikawa, Keiko Westh, Peter},
	month = {Sep},
	pages = {1347-1354},
	type = {Article},
	abstract = {We use the thermodynamic behaviour of I-propanol (1P) as a probe in ternary 1P-salt-H2O systems to elucidate the effect of a salt on the molecular organization of H2O. For salts, we have chosen CaCl2, NH4Cl, and (CH3)(4)NCl (TMAC). Having fixed the counter anion at Cl-, we compare here mainly the effects of chosen cations on H2O. Together with an earlier study on NaCl, we found that Ca2+, Na+, and NH4+ are hydrated by a number of H2O molecules and leave the bulk H2O away from the hydration shell unperturbed. The hydration numbers were found to be 6.4 +/- 1.6, and 1.2 +/- 0.4, for Ca2+ and NH4+, respectively with the hydration number 5.2 for Na+, the result of a simulation study, chosen as a reference. Thus, a salting out (also referred to as structure making, stabilizing, or kosmotropic) tendency would decrease in the order; Ca2+ > Na+ > NH4+. TMA(+), on the other hand, showed a more hydrophilic characteristics than the probing 1P. Thus, TMA(+) is rather chaotropic (salting in, structure breaking or destabilizing) within this methodology.},
	keywords = {AQUEOUS-SOLUTIONS, EXCESS CHEMICAL-POTENTIALS, HEAT-CAPACITIES, INTERMOLECULAR INTERACTIONS, MIXING SCHEMES, PARTIAL MOLAR ENTHALPIES, TETRAALKYLAMMONIUM HALIDES, TETRAMETHYL UREA, THERMODYNAMIC APPROACH, WATER MIXTURES},
	isbn = {0009-2673},
	url = {<Go to ISI>://000241479100004},
	author = {Koga,Yoshikata and Katayanagi, H. and Davies, J. V. and Kato, H. and Nishikawa, K. and Westh, P.}
}
@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 = {<Go to ISI>://000235297400050},
	author = {Westh, P. and Kato, H. and Nishikawa, K. and Koga,Yoshikata}
}
@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 \&DEG; 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 \&chi;(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 = {<Go to ISI>://000228982900071},
	author = {Miki, K. and Westh, P. and Nishikawa, K. and Koga,Yoshikata}
}
@article {1227,
	title = {Hydration number of glycine in aqueous solution: An experimental estimate},
	journal = {Journal of Chemical Physics},
	volume = {123},
	number = {23},
	year = {2005},
	note = {ISI Document Delivery No.: 996ADTimes Cited: 6Cited Reference Count: 31},
	month = {Dec},
	pages = {6},
	type = {Article},
	abstract = {An experimental estimate of hydration number, N-H, of glycine in aqueous solution is given by using the calorimetric methodology developed by us earlier, which is briefly reviewed. We found N-H to be 7 +/- 0.6 for glycine presumably in the zwitter ion form, 10 +/- 1 for sodium glycinate, and 5 +/- 0.4 for glycine hydrochloride. Both glycine and sodium glycinate seem to work purely as a hydration center without altering the nature of the bulk H2O away from the hydration shell. Glycine hydrochloride, in addition to the role of hydration center, seems also to act as a typical hydrophilic species such as polyols, urea, or polyethylene glycols. Hence, the effect of the latter on H2O is of a long range, like other hydrophilic species. (c) 2005 American Institute of Physics.},
	keywords = {25-DEGREES-C, fluctuations, H2O, INTRAMOLECULAR PROTON-TRANSFER, MIXING SCHEMES, MOLECULAR-ORGANIZATION, NONELECTROLYTES, PARTIAL MOLAR ENTHALPIES, TAUTOMERIZATION, WATER},
	isbn = {0021-9606},
	url = {<Go to ISI>://000234145900026},
	author = {Parsons, M. T. and Koga,Yoshikata}
}
@article {1201,
	title = {Hydrophobicity vs hydrophilicity: Effects of poly(ethylene glycol) and tert-butyl alcohol on H2O as probed by 1-propanol},
	journal = {Journal of Physical Chemistry B},
	volume = {109},
	number = {41},
	year = {2005},
	note = {ISI Document Delivery No.: 974SQTimes Cited: 8Cited Reference Count: 33},
	month = {Oct},
	pages = {19536-19541},
	type = {Article},
	abstract = {The enthalpic interaction between 1-propanol (IP) molecules, H-1P- 1P(E), was evaluated in 1P-poly(ethleneglycol) (PEG)-H2O and 1P-tert-butyl alcohol (TBA)-H2O ternary mixtures. The model-free and experimentally accessible quantity, H-1P-1p(E), indicates the effect of an additional 1P on the actual enthalpic situation of 1P in the mixture. It was shown earlier that the composition dependence of H-1P-1P(E) reflects the process how 1P modifies H2O. This H-1P-1P(E) pattern changes in the presence of a third component, PEG or TBA. The effects of PEG or TBA on the molecular organization of H2O were elucidated from these induced changes. Together with previous similar studies for the effects of methanol (ME), 2-propanol (2P), ethylene glycol (EG), and glycerol (Gly), we suggest a method and hence a possible scaling for sorting out hydrophobicity vs hydrophilicity of these alcohols by the changes induced to the loci of the maxima in H-1P-1P(E). We show that hydrophilicity scales with the number of oxygen, regardless of whether O is the ether -O- or the hydroxyl -OH. Hydrophobicity also scales with the number of carbon atoms for alcohols without a methyl group. For those with methyl groups, the hydrophobicity seems proportional to the total number of carbon with a different proportionality factor from those without methyl group.},
	keywords = {25-DEGREES-C, ALKANE-MONO-OLS, AQUEOUS-SOLUTIONS, EXCESS CHEMICAL-POTENTIALS, GLYCEROL, HOFMEISTER SERIES, MIXING SCHEMES, MOLECULAR-ORGANIZATION, PARTIAL MOLAR ENTHALPIES, THERMODYNAMIC APPROACH},
	isbn = {1520-6106},
	url = {<Go to ISI>://000232612100072},
	author = {Miki, K. and Westh, P. and Koga,Yoshikata}
}
@article {1177,
	title = {Thermodynamic properties of water in the water-poor region of binary water plus alcohol mixtures},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {83},
	number = {5},
	year = {2005},
	note = {ISI Document Delivery No.: 930KOTimes Cited: 2Cited Reference Count: 54},
	month = {May},
	pages = {420-429},
	type = {Article},
	abstract = {In our previous thermodynamic studies, we suggested that alcohol molecules in water-poor water + alcohol mixtures exist as alcohol clusters in a form similar to the pure alcohols. Here, we use calorimetry and densitometry to investigate how H2O interacts with alcohol clusters in water-poor binary aqueous mixtures of 12 different alcohols. The composition dependence of the measured excess partial molar enthalpy and volume of water (H-W(E) and V-W(E)), along with entropy data calculated from H-W(E) and literature data for excess chemical potentials, showed that in water-poor solutions of small alcohols such as methanol, ethanol, and 1-propanol, mutual water-water interactions are endothermic, but entropically favorable. Conversely, in long-chain solvents such as 1-octanol and 1-decanol, the interaction is exothermic and entropically unfavorable. We suggest that these observations reflect water-alcohol hydrogen bonding in short-chain solvents and water clustering with more hydrogen bonding than in pure water or "dewetting" in mixtures of the longer alcohols, respectively. The composition dependence of H-W(E) was also used to locate anomalies that specify the boundary between the mixing schemes characterizing the intermediate and the water-poor regions of alcohol + water mixtures.},
	keywords = {25-DEGREES-C, ALKANE-MONO-OLS, aqueous alkane-mono-ols, AQUEOUS-SOLUTIONS, BUTANOL MIXTURES, DILUTE-SOLUTIONS, entropy and, EXCESS ENTHALPY, excess partial molar enthalpy, MIXING SCHEMES, PARTIAL MOLAR VOLUMES, RICH REGION, TERT-BUTYL ALCOHOL, VOLUME},
	isbn = {0008-4042},
	url = {<Go to ISI>://000229414900003},
	author = {Liltorp, K. and Westh, P. and Koga,Yoshikata}
}
@article {913,
	title = {Effects of Na2SO4 and NaClO4 on the molecular organization of H2O},
	journal = {Journal of Physical Chemistry A},
	volume = {108},
	number = {10},
	year = {2004},
	note = {ISI Document Delivery No.: 801KFTimes Cited: 11Cited Reference Count: 16},
	month = {Mar},
	pages = {1635-1637},
	type = {Letter},
	abstract = {We study thermodynamic behaviors of 1-propanol (abbreviated as 1P) in ternary 1P-salt-H2O in order to elucidate the effects of salt on the molecular organization of H2O. We determine the excess partial molar enthalpy of 1P, H-1P(E), as a function of the mole fraction of 1P, x(1P), and the salt. We examine the x(1P) dependence of H-1P(E), and changes induced by the presence of salt are used to elucidate the effect of the salt on the molecular organization of H2O. We previously found that an NaCl ion pair binds 7 to 8 molecules of H2O, but has no effect on H2O outside of the hydration shell. Na2SO4 and NaClO4, on the other hand, modify the molecular organization of H2O each in different ways. In particular, ClO4- seems to participate in the hydrogen bond network of H2O and to retard the degree of fluctuation inherent in liquid H2O.},
	keywords = {25-DEGREES-C, AQUEOUS-SOLUTIONS, MIXING SCHEMES, PARTIAL MOLAR ENTHALPIES, THERMODYNAMIC APPROACH, WATER},
	isbn = {1089-5639},
	url = {<Go to ISI>://000220094100001},
	author = {Koga,Yoshikata and Westh, P. and Nishikawa, K.}
}
@article {912,
	title = {Toward understanding the Hofmeister series. 1. Effects of sodium salts of some anions on the molecular organization of H2O},
	journal = {Journal of Physical Chemistry A},
	volume = {108},
	number = {40},
	year = {2004},
	note = {ISI Document Delivery No.: 858TGTimes Cited: 18Cited Reference Count: 28},
	month = {Oct},
	pages = {8533-8541},
	type = {Article},
	abstract = {We studied a detailed thermodynamic behavior of 1-propanol (abbreviated as 1P) in mixed solvents of aqueous Na2SO4, NaOOCCH3, and NaClO4, and NaSCN. We measured the excess partial molar enthalpy of 1P, H-1P(E), in these mixed solvents at various initial salt concentrations. We then evaluated what we call the enthalpic interaction, H-1P-1P(E) = (partial derivativeH(1P)(E)/partial derivativen(1P)), where n(1P) is the amount of 1P. The composition dependence of H-1P-1P(E) changes in a characteristic manner on addition of a specific salt. This induced change in the behavior of H-1P-1P(E) is used to elucidate the effect of the salt on the molecular organization of H2O. Na+ ion seems to hydrate a number less than seven or eight molecules of H2O, leaving the bulk H2O outside the hydration shell unperturbed. SO42- also hydrates a number less than 26 H2O molecules with a concomitant increase in the degree of fluctuation of the bulk H2O. Na2SO4 as a whole hydrates the total of 26 H2O. CH3COO- ion modifies H2O in a similar manner as an alcohol. Cl- ion hydrates a number less than seven or eight H2O molecules leaving the bulk H2O in the same state as in pure H2O. NaCl as a whole hydrates the total of seven or eight molecules of H2O. ClO4- and SCN- participate in hydrogen bonding with the hydrogen bond network of H2O keeping its connectivity intact. However, they reduce the degree of fluctuation inherent in liquid H2O. Thus, each ion has its own unique manner of modifying H2O, except that ClO4- and SCN- modify H2O in almost the same way. Therefore, it seems fair to state that the phenomenological net result manifested as the Hofmeister series is due to multifacetted factors working in the holistic manner, and a single or a small number of parameters is not sufficient to explain its effect.},
	keywords = {1-PROPANOL, 25-DEGREES-C, ALKANE-MONO-OLS, AQUEOUS-SOLUTIONS, fluctuations, MIXING SCHEMES, PARTIAL MOLAR ENTHALPIES, THERMODYNAMIC APPROACH, WATER},
	isbn = {1089-5639},
	url = {<Go to ISI>://000224214100050},
	author = {Koga,Yoshikata and Westh, P. and Davies, J. V. and Miki, K. and Nishikawa, K. and Katayanagi, H.}
}
@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 = {<Go to ISI>://000186548700004},
	author = {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 {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 = {<Go to ISI>://000176849000018},
	author = {Parsons, M. T. and Koga,Yoshikata}
}
@article {5094,
	title = {Additive effect of 1-propanol and 2-propanol on molecular organization of H2O in the water-rich region: Excess chemical potential, partial molar enthalpy and volume of 1-propanol in 1-propanol-2-propanol-H2O at 25 degrees C},
	journal = {Bulletin of the Chemical Society of Japan},
	volume = {74},
	number = {5},
	year = {2001},
	note = {ISI Document Delivery No.: 443WKTimes Cited: 16Cited Reference Count: 25},
	month = {May},
	pages = {809-816},
	type = {Article},
	abstract = {Excess chemical potential, mu (E)(1P), partial molar enthalpy, H-1P(E) and volume of 1-propanol, V-1P(E), were determined as a function of mole fraction of l-propanol, rip, in mixed solvents of aqueous 2-propanol with various initial mole fraction of 2-propanol, x(2P)(0). The 1-propanol-1-propanol interaction functions, H-1P-1P(E) equivalent to N(partial derivativeH(1P)(E)/partial derivativen(1P)), and V-1P-1P(E) equivalent to N(partial derivativeV(1P)(E)/ partial derivativen(1P)), were evaluated by graphical differentiation. The rip-dependence of all these quantities indicates that l-propanol and 2-propanol modify the molecular organization of H2O in the same and additive manner in the water-rich region. The additive effect of 1-propanol and that of 2-propanol are in the ratio of (0.07/0.08).},
	keywords = {25-DEGREES-C, AQUEOUS 2-BUTOXYETHANOL, ENTROPIES, fluctuations, INTERMOLECULAR INTERACTIONS, LYSOZYME, MIXING SCHEMES, MIXTURES, TERT-BUTANOL},
	isbn = {0009-2673},
	url = {<Go to ISI>://000169365200004},
	author = {Hu, J. H. and Chiang, W. M. D. and Westh, P. and Chen, D. H. C. and Haynes, C. A. and Koga,Yoshikata}
}
@article {5109,
	title = {Mixing schemes for aqueous dimethyl sulfoxide: Support by X-ray diffraction data},
	journal = {Journal of Solution Chemistry},
	volume = {30},
	number = {10},
	year = {2001},
	note = {ISI Document Delivery No.: 505UTTimes Cited: 19Cited Reference Count: 18},
	month = {Oct},
	pages = {885-893},
	type = {Article},
	abstract = {Aqueous dimethyl sulfoxide (DMSO) was studied by X-ray diffraction at room temperature. The results indicated that there are three distinct composition regions. In the DMSO-rich region, DMSO molecules retain the same molecular arrangement as in the pure, state, while H2O does not show any structural feature. These findings are in the complete agreement with the suggestion by our earlier thermodynamic study on aqueous DMSO.((1)) In the H2O-rich region, there is an indication that DMSO molecules exist as small clusters bound mainly by S=O dipole attraction. Hence, hydrophobic CH3 groups point outward from such a cluster and DMSO acts in effect as a hydrophobic solute. This is also consistent with the findings of our earlier thermodynamic study. In the intermediate region, a gradual change in the radial distribution function with composition was observed.},
	keywords = {aqueous DMSO, DIMETHYLSULFOXIDE, intensity, LIQUID, MIXING SCHEMES, NEUTRON-DIFFRACTION, PARTIAL MOLAR ENTHALPIES, WATER MIXTURES, x-ray diffraction},
	isbn = {0095-9782},
	url = {<Go to ISI>://000172934500003},
	author = {Koga,Yoshikata and Kasahara, Y. and Yoshino, K. and Nishikawa, K.}
}
@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 = {<Go to ISI>://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 {4889,
	title = {A thermodynamic study of aqueous acetonitrile: excess chemical potentials, partial molar enthalpies, entropies and volumes, and fluctuations},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {78},
	number = {12},
	year = {2000},
	note = {ISI Document Delivery No.: 385LGTimes Cited: 9Cited Reference Count: 24},
	month = {Dec},
	pages = {1553-1560},
	type = {Article},
	abstract = {We measured vapour pressures of aqueous acetonitrile (abbreviated as ACN) at 6, 20, and 37 degreesC, from which excess chemical potentials of ACN (mu (E)(ACN)) were calculated. We also determined excess partial molar enthalpies of ACN (H-ACN(E)) at 6, 20, 30, 37, and 45 degreesC. From these data, excess partial molar entropies of ACN (S-ACN(E)) were calculated at 6, 20, and 37 degreesC. Using density data by Benson{\textquoteright}s group, excess partial molar volumes of ACN (V-ACN(E)) were evaluated. The response function data by the same group were also used to evaluate amplitude and wavelength of mean-square fluctuations in terms of volume, entropy, and cross between volume and entropy. All the above quantities and their dependence on the mol fraction of solute, i.e., the effect of additional solute on the above quantities were used to study the effect of acetonitrile on the molecular organization of H2O. It was found that acetonitrile works as a stronger structure-making solute than methanol. Rather its effect on H2O is about the same as that of propan-1-ol.},
	keywords = {2-BUTOXYETHANOL, 25-DEGREES-C, aqueous acetonitrile, BUTYL ALCOHOL, fluctuations, FREE-ENERGIES, interaction functions, MIXING SCHEMES, MIXTURES, NON-ELECTROLYTES, TERT-BUTANOL, VAPOR-PRESSURES, WATER-RICH REGION},
	isbn = {0008-4042},
	url = {<Go to ISI>://000166005500003},
	author = {Nikolova, P. V. and Duff, S. J. B. and Westh, P. and Haynes, C. A. and Kasahara, Y. and Nishikawa, K. and Koga,Yoshikata}
}
@article {4420,
	title = {Interactions in 1-propanol-urea-H2O: Chemical potentials, partial molar enthalpies, and entropies at 25 degrees C},
	journal = {Journal of Physical Chemistry B},
	volume = {102},
	number = {52},
	year = {1998},
	note = {ISI Document Delivery No.: 153MQTimes Cited: 27Cited Reference Count: 31},
	month = {Dec},
	pages = {10958-10965},
	type = {Article},
	abstract = {The excess partial molar enthalpies of I-propanol were determined in aqueous urea solutions. The total vapor pressures of 1-propanol-urea-H2O were also measured. The numerical analysis applied in a previous paper (J. Phys. Chem. B 1998, 102, 5182) was used to calculate partial pressures and, hence, the excess chemical potentials of each component. Thus, the excess partial molar entropies of l-propanol were obtained. From these partial molar quantities, the interaction functions between a pair of solute molecules were calculated following the method developed by us ( J. Phys. Chern. B 1996, 100, 5172). All these data seem to indicate that urea molecules lock into the hydrogen bond network of H2O, keep the connectivity of hydrogen bond intact, but reduce the degree of fluctuation that is characteristic of liquid water. I-Propanol molecules modify the hydrogen bond network in the same manner with or without urea, and hence the same amount of 1-propanol is required to break down the connectivity, i.e., the loss of hydrogen bond percolation. However, the H2O-mediated interaction between l-propanol solutes is weakened since the hydrogen bond fluctuation responsible for such an interaction is reduced by the presence of urea.},
	keywords = {AQUEOUS-SOLUTIONS, fluctuations, INTERMOLECULAR INTERACTIONS, KIRKWOOD-BUFF PARAMETERS, MIXING SCHEMES, MIXTURES, TERT-BUTYL ALCOHOL, UREA, WATER-RICH REGION, X-RAY-SCATTERING},
	isbn = {1089-5647},
	url = {<Go to ISI>://000077837200040},
	author = {To, E. C. H. and Hu, J. H. and Haynes, C. A. and Koga,Yoshikata}
}
@article {3402,
	title = {IONIC-CONDUCTIVITY IN THE WATER-RICH REGION OF AQUEOUS 2-BUTOXYETHANOL},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {73},
	number = {8},
	year = {1995},
	note = {ISI Document Delivery No.: RZ492Times Cited: 4Cited Reference Count: 22},
	month = {Aug},
	pages = {1294-1297},
	type = {Article},
	abstract = {Ionic conductivities of HCl, KOH, and KCl were measured in aqueous solutions of 2-butoxyethanol (BE) at 25 degrees C. The quantity, Lambda(j){\textquoteright} = sigma/x(j), which is almost proportional to the molar conductivity, was extrapolated to the infinite dilution x(j) {\textendash}> 0. sigma is the conductivity and x(j) is the mole fraction of j(= HCl, KOH, or KCl). The plots of (0) Lambda(j){\textquoteright}, the value of Lambda(j){\textquoteright} extrapolated to infinite dilution, against x(BE) showed a change in slope at x(BE) = 0.0175. The previous work from this laboratory indicated that the mixing scheme changes qualitatively at the same locus, x(BE) = 0.0175. By mixing scheme we simply mean the way in which BE and H2O molecules mix with each other. Assuming additivity in (0)h(j){\textquoteright} in terms of constituent ions, those values for H+OH- were calculated. Plots of (0) Lambda(H+OH-){\textquoteright} thus calculated as a function of x(BE) in the water-rich region, 0 < x(BE) < 0.0175, suggest that the hydrogen bond probability decreases in the bulk of solution, as x(BE) increases.},
	keywords = {AQUEOUS 2-BUTOXYETHANOL, BOND NETWORK, HYDROGEN, IONIC CONDUCTIVITIES, MIXING SCHEME, MIXING SCHEMES, MIXTURES, PARTIAL MOLAR ENTHALPIES, SCATTERING, TRANSITION, VOLUMES},
	isbn = {0008-4042},
	url = {<Go to ISI>://A1995RZ49200008},
	author = {Koga,Yoshikata and Loo, V. J. and Puhacz, K. T.}
}
