New (S)‐1‐phenylethylamine N‐arylidene derivatives as chiral dopants to liquid crystalline systems

Abstract

New chiral N‐arylidene (S)‐1‐phenylethylamines with a 4,4″‐biphenylene group in the central path of the rigid core were synthesized and their mesomorphic properties investigated. The helical twisting power and the temperature dependences of the helical pitch and the selective light reflection were analysed for several liquid crystalline systems based on 4‐pentyl‐4′‐cyanobiphenyl, E63 (Merck) and 4‐(n‐hexyloxy)phenyl 4′‐(n‐butyl)benzoate containing new chiral components. The chiral compounds investigated induce helical ordering effectively in all the host materials and have significant potential for applications. The results obtained for the new chiral compounds are compared with those for some previously studied similar chiral additives.

Acknowledgements

The authors are grateful to Merck KGaA, Darmstadt, for a gift of nematic E63. The authors would like to thank Dr. A.V. Turov (T.G. Shevchenko Kiev National University) for the measurements of ¹³C NMR spectra of the chiral compounds.