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In computational chemistry, a solvent model is a computational method that accounts for the behavior of solvated condensed phases. [1] [2] [3] Solvent models enable simulations and thermodynamic calculations applicable to reactions and processes which take place in solution. These include biological, chemical and environmental processes. [1]
COSMO [1] [2] (COnductor-like Screening MOdel) is a calculation method for determining the electrostatic interaction of a molecule with a solvent. COSMO is a dielectric continuum model [1] [3] [4] [5] (a.k.a. continuum solvation model). These models can be used in computational chemistry to model solvation effects. COSMO has become a popular ...
logX m = ƒ 1 logX 1 + ƒ 2 logX 2. Where X m is the mole fraction solubility of the solute, X 1 and X 2 denote the mole fraction solubility in neat cosolvent and water. While this model is only correlative in nature, further analysis allows for the creation of a predictive element. Simplifying the above equation to: logX m = logX 2 + σ • ƒ 1
Implicit solvation (sometimes termed continuum solvation) is a method to represent solvent as a continuous medium instead of individual “explicit” solvent molecules, most often used in molecular dynamics simulations and in other applications of molecular mechanics.
The polarizable continuum model (PCM) is a commonly used method in computational chemistry to model solvation effects. If it is necessary to consider each solvent molecule as a separate molecule, the computational cost of modeling a solvent-mediated chemical reaction would grow prohibitively high.
Polar solvents can be used to dissolve inorganic or ionic compounds such as salts. The conductivity of a solution depends on the solvation of its ions. Nonpolar solvents cannot solvate ions, and ions will be found as ion pairs. Hydrogen bonding among solvent and solute molecules depends on the ability of each to accept H-bonds, donate H-bonds ...
The solvent-rich phase is close to pure solvent. This is peculiar to polymers, a mixture of small molecules can be approximated using the Flory–Huggins expression with N = 1 {\displaystyle N=1} , and then ϕ cp = 1 / 2 {\displaystyle \phi _{\text{cp}}=1/2} and both coexisting phases are far from pure.
B reflects the energy of binary interactions between solvent molecules and segments of polymer chain. When B > 0, the solvent is "good," and when B < 0, the solvent is "poor". For a theta solvent, the second virial coefficient is zero because the excess chemical potential is zero; otherwise it would fall outside the definition of a theta solvent.