A novel type of banana liquid crystals based on 1-substituted naphthalene-2,7-diol cores

The effect of lateral 1-substitution in naphthalene-2,7-diol with CH₃, CN and Cl on mesomorphic properties is studied. DSC and X-ray diffraction, texture observation and dielectric measurements have been performed. For the non-substituted core the high-temperature B_X phase and the B₄ phase occur while in CH₃ and Cl substituted compounds the B₂ phases are found. In the CN derivatives, besides the crystalline-like phase N, the phase transition between the chiral B₂ and racemic B₂ phases is observed.