Synthesis, characterization and photophysical study of cholesterol functionalized azo-based room temperature liquid crystals

Four new liquid crystalline materials (HA1-HA4) with cholesteryl group and azo-ester linking group interconnected with two-side substituted flexible alkoxy side chains were deliberated and synthesized. The structure confirmation of the azo mesogens was investigated by using FT-IR, 1H NMR, and 13C NMR techniques. The phase behavior of the materials was investigated by crossed polarizing optical microscopy (POM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) techniques. All four targeted materials shows smectic type mesogenic properties and further stabilized up to room temperature to lower temperature. The structure-property relationship of present azo-based materials was discussed to investigate the scope of mesogenic properties. All four materials (HA1-HA4) display wide temperature range mesophase as 52.5 degrees C, 54.7 degrees C, 52.7 degrees C, and 54.1 degrees C. The photoresponsive properties of the azo-based bi-substituted materials were well examined by UV study.

Automated summary

Four new liquid crystalline materials (HA1-HA4) with cholesteryl group and azo-ester linking group were synthesized and their structure and phase behavior were investigated. The materials showed smectic type mesogenic properties and displayed wide temperature range mesophase. The photoresponsive properties of the azo-based bi-substituted materials were also examined.