Molecular dynamics simulations of a flexible molecule in a liquid crystalline solvent

Molecular dynamics simulations of a hexane molecule in isotropic, nematic, and smectic phases are reported. The interactions between the solvent molecules is modeled using the Gay–Berne potential and the hexane–solvent potential is modeled as an explicit site–site interaction. The conformational distributions are reported of the hexane molecule at a fixed temperature but at different densities in isotropic, nematic, and smectic phases, and these are compared with the results from Monte Carlo simulations on an isolated molecule at the same temperature. The positions and orientations of the hexane molecule at each time step in the molecular dynamics simulations are used to calculate interproton dipolar coupling constants. These data are used to test the mean field models which have been applied with dipolar couplings obtained previously from nuclear magnetic resonance (NMR) experiments to yield conformational distributions.

[1]  D. J. Tildesley,et al.  Computer simulation of the behaviour of a solute in a model liquid crystalline solvent , 1994 .

[2]  A. Pines,et al.  Two-dimensional proton NMR studies of the conformations and orientations of n-alkanes in a liquid-crystal solvent , 1993 .

[3]  J. Emsley,et al.  The conformations adopted by alkyl chains in α,ω-bis(aryl)alkanes in liquid-crystalline phases , 1993 .

[4]  A. Terzis,et al.  Conformations of n-hexane from proton dipolar couplings: the role of torsion angle fluctuations , 1992 .

[5]  G. R. Luckhurst,et al.  Computer simulation studies of the dependence on density of the orientational order in nematic liquid crystals , 1992 .

[6]  N. G. Almarza,et al.  Monte Carlo simulation of liquid n-alkanes. I: Intramolecular structure and thermodynamics , 1992 .

[7]  Luis F. Rull,et al.  Liquid crystal phase diagram of the Gay-Berne fluid , 1991 .

[8]  M. P. Allen,et al.  Computer Simulations of Mesogenic Molecules Using Realistic Atom-Atom Potentials , 1991 .

[9]  G. R. Luckhurst,et al.  Computer simulation studies of anisotropic systems. XIX. Mesophases formed by the Gay-Berne model mesogen , 1990 .

[10]  E. Samulski,et al.  Alkyl chains in a nematic field. 2. Temperature and chain length dependence of orientational ordering , 1990 .

[11]  E. Samulski,et al.  Alkyl chains in a nematic field. 1. A treatment of conformer shape , 1990 .

[12]  J. Banavar,et al.  Computer Simulation of Liquids , 1988 .

[13]  G. R. Luckhurst,et al.  Computer simulation studies of anisotropic systems: XVII. The Gay-Berne model nematogen , 1987 .

[14]  A. Pines,et al.  Assignment of dipolar couplings and estimation of conformational probabilities in partially oriented hexane , 1987 .

[15]  E. Samulski,et al.  Flexible solutes in a uniaxial field: a deuterium NMR study of n-alkanes in a nematic solvent , 1987 .

[16]  E. Burnell,et al.  Size and shape effects on the orientation of rigid molecules in nematic liquid crystals , 1987 .

[17]  G. R. Luckhurst,et al.  A theory of orientational ordering in uniaxial liquid crystals composed of molecules with alkyl chains , 1982, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[18]  B. Berne.  Modification of the overlap potential to mimic a linear site-site potential , 1981 .

[19]  G. R. Luckhurst,et al.  The effect of internal motion on the orientational order parameters for liquid crystalline systems , 1980 .

[20]  Antoinette J. Taylor,et al.  Thermodynamic and structural properties of liquids modelled by ‘2-Lennard-Jones centres’ pair potentials , 1977 .

[21]  J. Straley,et al.  Ordered phases of a liquid of biaxial particles , 1974 .

[22]  S. Marčelja.  Chain ordering in liquid crystals. I. Even‐odd effect , 1974 .

[23]  G. R. Luckhurst,et al.  Orientational order in the 4-n-alkyloxy-4′-cyanobiphenyls , 1988 .

[24]  Jean-Paul Ryckaert,et al.  Molecular dynamics of liquid n-butane near its boiling point , 1975 .