title: Transferable potentials for phase equilibria. 7. Primary, secondary, and tertiary amines, nitroalkanes and nitrobenzene, nitriles, amides, pyridine, and pyrimidine.
abstract: The transferable potentials for phase equilibria (TraPPE) force fields are extended to amine, nitro, nitrile, and amide functionalities and to pyridine and pyrimidine. In many cases, the same parameters for a functional group are used for both united-atom and explicit-hydrogen representations of alkyl tails. Following the TraPPE philosophy, the nonbonded interaction parameters were fitted to the vapor-liquid coexistence curves for selected one-component systems. Coupled-decoupled configurational-bias Monte Carlo simulations in the Gibbs ensemble were applied to neat (methyl-, dimethyl-, trimethyl-, ethyl-, diethyl-, or triethyl-)amine, nitromethane, nitroethane, nitrobenzene, acetonitrile, propionitrile, acetamide, propanamide, butanamide, pyridine, and pyrimidine. Excellent agreement with experimental results was found, with the mean unsigned errors being less than 1% for both the critical temperature and the normal boiling temperature. Similarly, the liquid densities at low reduced temperatures are reproduced to within 1%, and the deviation for the critical densities is about 4%. Additional simulations were performed for the binary mixtures of methylamine + n-hexane, diethyl ether + acetonitrile, 1-propanol + acetonitrile, and nitroethane + ethanol. With the exception of the methylamine/n-hexane mixture for which the separation factor is substantially overestimated, agreement with experiment for the other three mixtures is very satisfactory.
authors.affiliation: Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, USA.
authors.forename: Collin D
authors.initials: CD
authors.lastname: Wick
authors.forename: John M
authors.initials: JM
authors.lastname: Stubbs
authors.forename: Neeraj
authors.initials: N
authors.lastname: Rai
authors.forename: J Ilja
authors.initials: JI
authors.lastname: Siepmann
mesh_terms: D000577:Amides / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D003198:Computer Simulation; D009570:Nitriles / Q000737:chemistry*; D009574:Nitro Compounds / Q000737:chemistry*; D044367:Phase Transition; D011725:Pyridines / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*
chemical_list: D000577:Amides; D000588:Amines; D009570:Nitriles; D009574:Nitro Compounds; D011725:Pyridines; D011743:Pyrimidines