CLARK, S. J., ADAM, C. J., CLEAVER, D. J. and CRAIN, J. (1997). Conformational energy landscapes of liquid crystal molecules. Liquid Crystals, 22 (4), 477-482.Full text not available from this repository.
The conformational energy landscape of the prototypical nematic liquid crystal 4-pentyl-4'cyanobiphenyl (5CB) is studied using first principles computer modelling. It is found that the most favourable conformation occurs when the two constituent phenyl rings are inclined at an angle of 31 degrees with respect to each other. Also, the orientation of the alkyl chain is found to have an important influence on the ring-ring torsional potential. We fit the energy surface of these coupled torsions to yield an accurate intramolecular potential for use in empirical modelling. To test the strength of the coupling between the alkyl tail and the phenyl rings and the cyano group, we also calculate potentials for the relative orientation of the phenyl rings in biphenyl and cyanobiphenyl (0CB). Our calculations are performed using density functional theory using pseudo-potentials and the generalized gradient approximation to exchange and correlation. The molecular electronic wavefunction is expanded in terms of a plane wave basis set. We compare our results with recent NMR and Gaussian-based quantum chemistry calculations where available.
|Research Institute, Centre or Group:||Materials and Engineering Research Institute > Polymers Nanocomposites and Modelling Research Centre > Materials and Fluid Flow Modelling Group|
|Depositing User:||Hilary Ridgway|
|Date Deposited:||12 Apr 2010 09:05|
|Last Modified:||29 Sep 2010 09:32|
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