On the molecular theory of aqueous electrolyte solutions. I. The solution of the RHNC approximation for models at finite concentration

Abstract

Articles you may be interested inElectrolyte diodes with weak acids and bases. I. Theory and an approximate analytical solution On the molecular theory of aqueous electrolyte solutions. IV. Effects of solvent polarizability J. Chem. Phys. 92, 1345 (1990); 10.1063/1.458145 On the molecular theory of aqueous electrolyte solutions. II. Structural and thermodynamic properties of different models at infinite dilution J. Chem. Phys. 89, 5843 (1988); 10.1063/1.455535 Simple electrolytes in the mean spherical approximation. III. A workable model for aqueous solutionsThis paper describes a theoretical study of the thermodynamic, dielectric, and structural properties of model aqueous electrolyte solutions. The model considered consists of hard sphere ions immersed in a hard polarizable dipole tetrahedral-quadrupole solvent with waterlike parameters. The calculations involve the solution of the reference hypemetted-chain (RHNC) approximation for ion-solvent mixtures at finite concentration and some details of the general method are discussed. The influence of the molecular polarizabiIity of the solvent particles is treated at the self-consistent mean field (SCMF) level and, surprisingly, the mean dipole moment of the solvent is found to be nearly independent of the salt concentration. Numerical results are reported for model alkali halide solutions and other 1: 1 electrolytes, and comparisons are made with experimental results at 25 ·C. The agreement obtained between theory and experiment is variable depending upon the particular property and solution considered. In addition to the explicit numerical results for aqueous electrolytes several general analytical results are also given. The most interesting of these are expressions for the low concentration large separation limiting behavior of the ion-solvent and solvent-solvent radial distribution functions. caP (12) = haP (12) -lngaP (12) -u ap (12)lkT,

Morphometric approach to thermodynamic quantities of solvation of complex molecules: Extension to multicomponent solvent

“…The radial-symmetric IET is replaced by the angle-dependent IET [22][23][24][25] for molecular liquids applied to a multipolar model for water. A feature of this theory is that the water-water and solute-water orientational correlations are explicitly taken into account.…”

“…25 Spherical ions (e.g., Na + and Cl − ) can also be included in the model water without difficulty. 22,24,37,38 Further, we believe that the solute-solvent van der Waals and electrostatic inter- actions can be incorporated in the MA, as long as the ions are present and their concentration is high enough to screen the electrostatic interaction (this is the case for aqueous solution under physiological conditions). We are now investigating this incorporation.…”

“…21 In these problems, the solvation entropy is the key quantity calculated by modeling a protein with a fixed structure as a set of fused hard spheres. The solvent is formed either by hard spheres or water molecules modeled as hard spheres in which point multipoles [22][23][24][25] are embedded. In studies on the unfolding mechanisms, the SFE or related quantities of solvation thermodynamics must be calculated for a number of different structures of a protein, and the use of an efficient method, such as the MA, is highly necessitated.…”

Hydration free energy of hard-sphere solute over a wide range of size studied by various types of solution theories

“…The multipole model was adopted for the water molecule; it is a hard sphere of diameter 2.8Å in which a point dipole and a point quadrupole of tetrahedral symmetry are embedded [28]. The dipole moment was determined through the iterative procedure given in [28] to incorporate the polarization effect in the mean-field sense. The resulting value at 25…”

Application of Hydration Thermodynamics to the Evaluation of Protein Structures and Protein-Ligand Binding

“…The hydration entropy, which strongly depends on the details of the protein polyatomic structure, is calculated using a hybrid of the angle-dependent integral equation theory [35][36][37][38][39], i.e., a statisticalmechanical theory for molecular liquids, and the morphometric approach [28]. In the angle-dependent integral equation theory, the role of water as a molecular ensemble is fully considered.…”