title: Molecular dynamics and Monte Carlo simulations for the structure of the aqueous trimethylammonium chloride solution in the 0.2-1 molar range.
abstract: Molecular dynamics and Monte Carlo simulations have been performed for characterizing the structure of the 0.2 and 1 molar aqueous trimethylammonium chloride solutions. Atomic charges were derived through the CHELPG and RESP fits to the molecular electrostatic potentials calculated for the cation in water at the IEF-PCM/B3LYP level using the 6-31G* and 6-311++G** basis sets. Maxima and minima of the calculated radial distribution functions were not sensitive to the four atomic charge sets. Simulated solution structures suggest non-negligible solute-solute interactions and remarkable inhomogeneity at both concentrations. This means that equilibrium ratios, derived for conformers/tautomers by means of ab initio calculations with the IEF-PCM continuum dielectric solvent model, should be corrected for free energy changes following solute association when compared to experimental data obtained for the 0.1-1 molar aqueous solutions.
authors.affiliation: CNR-National Research Council of Italy, Istituto di Chimica dei Composti Organo Metallici, (ICCOM), Pisa, Italy. s.monti@iccom.cnr.it
authors.forename: Susanna
authors.initials: S
authors.lastname: Monti
authors.forename: Peter I
authors.initials: PI
authors.lastname: Nagy
mesh_terms: D056004:Molecular Dynamics Simulation; D009010:Monte Carlo Method; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000644:Quaternary Ammonium Compounds; D014867:Water