Mesomorphic Properties of Novel Supramolecular Calix[4]arene Schiff Base Ester Derivatives: Design and Biological Investigation

Two homologues series of liquid crystals based on calix[4]arene core have been prepared by the condensing of Schiff base derivatives of 4‐ n ‐alkoxy benzaldehyde and 4‐amino benzoic acid at the lower rim of tert ‐butyl calix[4]arene. They have been designed to a correlation between the molecular structure and mesomorphism with reference to ‐CH=N‐ and ‐COO‐ linkage group. All these compounds were characterized by elemental analyses and spectroscopic techniques such as FTIR, 1 H‐NMR, and 13 C‐NMR. Mesomorphic behaviour of novel materials were studied by polarising optical microscope (POM), differential scanning calorimetry (DSC) and X‐ray diffraction measurements to confirm the presence of mesophase. Comp.C 7 ‐I to C 18 ‐I (Series‐1) and C 4 ‐II to C 18 ‐II (Series‐2) shows smectic and nematic mesophase enantiotropically manner. Comp.C 3 ‐I, C 7 ‐I, C 6 ‐II, C 7 ‐II, C 12 ‐II subjected to in vitro antimicrobial screening against two gram ( +ve) bacteria ( S.aureus , S.Pyogenes ), two gram (‐ve) bacteria ( E.coli , P.aeruginosa ) and three fungal strains ( C.albicans , A.Niger , A.clavatus ).