TY - JOUR
T1 - Water's Thermal Pressure Drives the Temperature Dependence of Hydrophobic Hydration
AU - Cerdeiriña, Claudio A.
AU - Debenedetti, Pablo G.
N1 - Funding Information:
The authors are grateful to B. Widom for fruitful discussions. C.A.C. acknowledges support from the Spanish Ministry of Education, Culture, and Sports, grant no. PRX15-00152, and from the Spanish Ministry of Economy and Competitiveness, grant no. FIS2017-89361-C3-3-P.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2018/4/5
Y1 - 2018/4/5
N2 - With the aid of literature experimental data and reported results from molecular simulation, two thermodynamic relations are found to provide a theoretical basis for the understanding of a variety of characteristic features associated with the solvation of small nonpolar molecules in water. Thus, the large and positive solvation heat capacity, enthalpy-entropy compensation, the solubility minimum and solvation free energy maximum with respect to temperature, enthalpy convergence, and entropy convergence are rationalized in a unified way. Our key finding is that all of these phenomena are driven by the thermal pressure coefficient of pure water, which, via the isobaric thermal expansivity and the isothermal compressibility, reflects its unusual thermodynamics. Remarkably, the solubility minimum is found to be a direct consequence of water's density maximum.
AB - With the aid of literature experimental data and reported results from molecular simulation, two thermodynamic relations are found to provide a theoretical basis for the understanding of a variety of characteristic features associated with the solvation of small nonpolar molecules in water. Thus, the large and positive solvation heat capacity, enthalpy-entropy compensation, the solubility minimum and solvation free energy maximum with respect to temperature, enthalpy convergence, and entropy convergence are rationalized in a unified way. Our key finding is that all of these phenomena are driven by the thermal pressure coefficient of pure water, which, via the isobaric thermal expansivity and the isothermal compressibility, reflects its unusual thermodynamics. Remarkably, the solubility minimum is found to be a direct consequence of water's density maximum.
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U2 - 10.1021/acs.jpcb.7b11100
DO - 10.1021/acs.jpcb.7b11100
M3 - Article
C2 - 29227672
AN - SCOPUS:85039074748
SN - 1089-5647
VL - 122
SP - 3620
EP - 3625
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 13
ER -