title: Parametrization of 2,2,2-trifluoroethanol based on the generalized AMBER force field provides realistic agreement between experimental and calculated properties of pure liquid as well as water-mixed solutions.
abstract: We present a novel force field model of 2,2,2-trifluoroethanol (TFE) based on the generalized AMBER force field. The model was exhaustively parametrized to reproduce liquid-state properties of pure TFE, namely, density, enthalpy of vaporization, self-diffusion coefficient, and population of trans and gauche conformers. The model predicts excellently other liquid-state properties such as shear viscosity, thermal expansion coefficient, and isotropic compressibility. The resulting model describes unexpectedly well the state equation of the liquid region in the range of 100 K and 10 MPa. More importantly, the proposed TFE model was optimized for use in combination with the TIP4P/Ew and TIP4P/2005 water models. It does not manifest excessive aggregation, which is known for other models, and therefore, it is supposed to more realistically describe the behavior of TFE/water mixtures. This was demonstrated by means of the Kirkwood-Buff theory of solutions and reasonable agreement with experimental data. We explored a considerable part of the parameter space and systematically tested individual combinations of parameters for performance in combination with the TIP4P/Ew and TIP4P/2005 water models. We observed ambiguity in parameters describing pure liquid TFE; however, most of them failed for TFE/water mixtures. We clearly demonstrated the necessity for balanced TFE-TFE, TFE-water, and water-water interactions which can be acquired only by employing implicit polarization correction in the course of parametrization.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic (AS CR) , Flemingovo nám. 2, 166 10 Praha 6, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Vymětal
authors.forename: Jiří
authors.initials: J
authors.lastname: Vondrášek
mesh_terms: D004058:Diffusion; D005740:Gases / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D012997:Solvents / Q000737:chemistry; D055672:Static Electricity; D014270:Trifluoroethanol / Q000737:chemistry*; D014783:Viscosity; D014835:Volatilization; D014867:Water / Q000737:chemistry*
chemical_list: D005740:Gases; D008055:Lipids; D012997:Solvents; D014867:Water; D014270:Trifluoroethanol