Effect of azo and ester linkages on rod shaped Schiff base liquid crystals and their photophysical investigations

• We have synthesized and characterized new rod shaped liquid crystalline compounds.
• Azo and ester linkage affected the mesomorphism.
• All the compounds exhibited good LC mesophase depend upon the alkyl chain length.
• Azo-Schiff base compounds exhibited photoisomerization.

Two new series of rod shaped Schiff base containing liquid crystal compounds with azo and ester linkages have been synthesized and characterized respectively. The rod like molecules containing cinnamate linkages with four different alkyl spacers (n = 6, 8, 10 and 12) and influence of linking group have been elucidated. Considerable changes in mesomorphic properties were noticed starting from Nematic to Smectic-C on changing of azo and ester linkages along with different terminal alkyl chain lengths. The mesomorphic properties of both series are compared. Photosensitive azobenzene group undergoes photoisomerization under UV light and monitored by UV–Visible spectroscopy.

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