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The synthesis and mesomorphic properties of new triazole liquid-crystalline are presented and discussed. These triazole derivatives have been synthesized by reacting 4-hydrazoic iodobenzene with the 4-alkyl phenyl acetylene in dimethyl formamide (DMF). The molecular structure is characterized by 1H NMR,Fourier transform infrared spectroscopy(FTIR),time-of-flight mass spectrometry(TOF-MS) and the mesomorphic properties are characterized by polarizing optical microscope (POM) and (DSC). These new triazole liquid-crystallines have higher melting point and clearing point and the final compounds display both nematic and smectic liquid-crystalline phases. [ABSTRACT FROM AUTHOR]

When mesogenic compound with high birefringence was incorporated into a chiral nematic liquid crystal (N*-LC), the resulting composites generated higher birefringence to change the selective reflection of N*-LC. The effects of variables such as content of chiral dopant and mesogenic compound, temperature, and AC voltage on the selective reflection of N*-LC were systematically studied. [ABSTRACT FROM AUTHOR]

Twelve compounds based on lateral fluorinated bistolane moieties with cyano or trifluoromethyl terminal groups were synthesised with Hagihara–Sonogashira cross-coupling reaction. The molecular structures of the compounds were confirmed by Fourier transform infrared, 1H-nuclear magnetic resonance and mass spectrometry. The transition temperatures, optical textures and optical anisotropies were determined by differential scanning calorimetry, polarizing optical microscopy and ultraviolet microscopy. The effects of the terminal substituents and lateral fluorosubstituent group on their physical properties were investigated and discussed. The compounds with lateral double fluorosubstituent and cyano terminal group exhibited nematogenic texture, while other compounds showed smectic phase. All the compounds exhibited wide liquid crystal temperature ranges and high clearing points. Interestingly, the compounds have the high birefringence in the range of between 0.480 and 0.633. [ABSTRACT FROM AUTHOR]