Liquid crystalline compounds containing hydrogenated six-membered heterocyclic rings

New liquid crystalline compounds containing saturated six-membered heterocycles (piperidine, tetrahydrothiapyrane and its oxidized forms) have been synthesized. The terminal sulfoxide and sulfone groups have the tendency to provide smectic properties. Liquid crystalline derivatives of U-piperidinobenzonitrile have higher positive dielectric anisotropy than corresponding phenylclohexanes. The absence of liquid crystalline properties was established for 4-substituted phenols and cyclohexyl trans-2, 5-p-dioxanedicar pOxylates.