Solvation of Ions in Aqueous Solutions of Hydrophobic Solutes
نویسندگان
چکیده
The self-diffusion of N a + , E t 4 N + and I in mixtures of water with n-propanol at 25 °C and with lert-butanol at 30 °C was measured as function of salt concentration and solvent composition. The limiting self-diffusion coefficients of the ions were used to compute the ionic radii. The influence of the composition of the solvent on the solvation of the ions is discussed. In aqueous solutions of both alcohols the effective ionic radii are reduced. The strongest influence is found for the same solvent composition for which the highest concentration of the alcohol clusters has been reported. Hydration of the clusters of n-propanol causes a vanishing of the second hydration shell of N a + and the first one of E t 4 N + and I . In the case of terf-butanol even the first hydration shell of N a + is partially reduced.
منابع مشابه
SM6: A Density Functional Theory Continuum Solvation Model for Calculating Aqueous Solvation Free Energies of Neutrals, Ions, and Solute-Water Clusters.
A new charge model, called Charge Model 4 (CM4), and a new continuum solvent model, called Solvation Model 6 (SM6), are presented. Using a database of aqueous solvation free energies for 273 neutrals, 112 ions, and 31 ion-water clusters, parameter sets for the mPW0 hybrid density functional of Adamo and Barone (Adamo, C.; Barone, V. J. Chem. Phys. 1998, 108, 664-675) were optimized for use with...
متن کاملFrom hydrophobic to hydrophilic behaviour: A simulation study of solvation entropy and free energy of simple solutes
We describe atomistic simulations of the free energy and entropy of hydration of ions in aqueous solution at 25 °C using a simple point charge model ~SPC/E! for water and charged spherical Lennard-Jones solutes. We use a novel method with an extended Lagrangian or Hamiltonian in which the charge and the size of the ions are considered as dynamical variables. This enables us to determine thermod...
متن کاملSolvation in supercritical water *
Cochran, H.D., Cummings, P.T. and Karaborni, S., 1992. Solvation in supercritical water. Fluid Phase Equilibria, 71: 1-16. The aim of this work is to determine the solvation structure in supercritical water compared with that in ambient water and in simple supercritical solvents. Molecular dynamics studies have been undertaken of systems that model ionic sodium and chloride, atomic argon, and m...
متن کاملSimulation of supercritical water and of supercritical aqueous solutions
Molecular dynamics (MD) calculations have been performed to determine equilibrium structure and properties of systems modeling supercritical (SC) water and SC aqueous solutions at two states near the critical point using the simple point charge (SPC) potential model of Berendsen et al. for water. Both thermodynamic and dielectric properties from the simulations for pure water are accurate in co...
متن کاملElectrical Conductivity Studies of 1-Butyl-3-methylimidazolium Salicylate as an Active Pharmaceutical Ingredient Ionic Liquid (API-IL) in Aqueous Amino Acids Solutions
The molar conductivity data of 1-butyl-3-methylimidazolium salicylate, [BMIm][Sal] as an active pharmaceutical ingredient ionic liquid (API-IL) have been determined in water and aqueous solutions of amino acids, glycine and L-alanine at T= (288.15 to 318.15) K. The molar conductivity data were analyzed by low concentration Chemical Model (lcCM) and limiting molar conductivities ( ), ion associa...
متن کامل