Aliphatic Liquid Crystals with Positive Dielectric Anisotropy

Article abstract of DOI:10.1002/hlca.19840670407

Cyanoethyl-substituted cyclohexyl cyclohexanoates, bi(cyclohexanes) and phenyl cyclohexanes were synthesized.Their mesomorphic behaviour is compared to that of the corresponding cyano derivatives. (Cyanoethyl)cyclohexyl cyclohexanoates show mesomorphic properties in contrast to the corresponding cyano derivatives.Separation of the cyano substituent from the rigid core of an anisotropic aliphatic compound by methylene groups enhances the thermodynamic stability of its mesophase.In aromatic compounds, the cyanoethyl group leads to lower clearing points.These phenomena are attributed to the influence of steric effects on the packing density and to the dependence of the clearing point on molecular association.