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Monte Carlo simulations of pure liquid substituted benzenes with OPLS potential functions
Author(s) -
Jorgensen William L.,
Laird Ellen R.,
Nguyen Toan B.,
TiradoRives Julian
Publication year - 1993
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540140208
Subject(s) - anisole , chemistry , aniline , enthalpy of vaporization , thermodynamics , benzene , monte carlo method , benzonitrile , standard enthalpy of formation , intermolecular force , vaporization , computational chemistry , molecule , enthalpy , organic chemistry , physics , statistics , mathematics , catalysis
Intermolecular potential functions have been developed for use in computer simulations of substituted benzenes. Previously reported optimized potentials for liquid simulations (OPLS) for benzene and organic functional groups were merged and tested in Monte Carlo statistical mechanics simulations for the pure liquids of toluene, m ‐cresol, anisole, aniline, and benzonitrile at 25°C at 1 atm. The merged potential functions yielded acceptable thermodynamic results for the liquids except in the case of aniline, for which the error in the heat of vaporization was 12%. This was remedied by enhancing the polarity of the model to be more consistent with the observed dipole moment of aniline. Overall, the average errors in computed heats of vaporization and densities were then 2 and 1%, respectively. The structures of the liquids were characterized through energy and radial distribution functions. For m ‐cresol and aniline, the molecules participate in averages of 1.6 and 1.4 hydrogen bonds, respectively. Condensed phase effects on the torsional energies for anisole, m ‐cresol, and aniline were found to be small; m ‐cresol has a slightly enhanced tendency to be nonplanar in the liquid than in the gas phase, while anisole shows the opposite pattern. © 1993 John Wiley & Sons, Inc.