Correlation between molecular chirality and helical twisting power: a computer simulation study

Abstract

The helical structure of the chiral nematic phases induced by chiral dopants in nematic solvents provides a macroscopic information of the molecular chirality of the dopant. Chiral dopant molecules considered in this paper are challenging systems because their twisting ability has a relatively strong dependence on the molecular structure. Several classes of the flexible chiral dopants such as the binaphthyl derivatives characterized by a conformational chirality are investigated. In addition, we will investigate the odd–even effect on the helical twisting power of two azobenzene derivatives and the twist inversion with temperature and solvent of the (1S)-1-naphthalen-1-ylethyl amide and trans-4,5-diaryl-1,3-dioxolanes derivatives, respectively. In this work two different theoretical approaches, the surface model and the scaled chiral index, are studied which are combined with molecular dynamics simulations of the single molecule in the gas phase. The results are compared with the experimental values of the helical twisting power.

Acknowledgements

H. Kamberaj would like to thank Manchester Metropolitan University for funding the project and EPSRC for support.