Towards in silico liquid crystals. Realistic transition temperatures and physical properties for n-cyanobiphenyls via molecular dynamics simulations.

TLDR: By using the united-atom force field developed herein, it is shown that the experimental isotropic-nematic transition temperatures are reproduced within 4 K, allowing a molecular-level interpretation of the odd-even effect along the series.

Abstract: We have studied the important n-cyano biphenyl series of mesogens, n=4-8 using modelling and molecular dynamics simulations. We have been able to obtain spontaneously ordered nematics upon cooling isotropic samples of 250 molecules. We show that, using the united atom force field developed here, the experimental isotropic–nematic transition temperatures are reproduced within 4 K, allowing a molecular level interpretation of the odd–even effect along the series. Other properties, like densities, orientational order parameters and NMR residual dipolar couplings are also well reproduced, demonstrating the feasibility of predictive in silico modelling of nematics from the molecular structure.