Calamitic nematic liquid crystals synthesis and characterisation from bromo-chlorophenol and bromo-chlorobenzoic acid

Insecticide-derived calamitic liquid crystals were synthesised and characterised using various analytical methods, including infrared and nuclear magnetic resonance spectroscopy. In this study, the liquid crystal properties of 4-bromo-2-chlorophenol and 4-bromo-2-chlorobenzoic acid derivatives were investigated. Out of 25 newly prepared compounds, 19 compounds exhibited nematic phase. A few middle-ordered compounds exhibit an extra nematic X phase. One molecule exhibits the SmA mesophase. The liquid crystal properties were confirmed by polarised optical microscopy, differential scanning calorimetry, and X-ray diffraction studies.