Novel liquid crystals have the formula STR1 wherein two of the rings A, B and C are aromatic and the third is a trans-1,4-disubstituted cyclohexane ring and R is alkyl or alkoxy each of 1 - 12 C-atoms. These compounds are particularly useful as additional components in liquid crystal dielectrics whereby the clear point of the dielectric is raised and the viscosity thereof is not deleteriously affected.