Abstract
The synthesis and characterisation of stable achiral asymmetrical four-ring banana-shaped molecules are presented. These consist of a laterally fluoro-substituted 3,4ʹ-disubstituted biphenyl unit with an ester linkage between the phenyl rings as the central unit in 4-(N-4ʹ-n-alkyloxysalicylidene)aminophenyl [2-fluoro-5-(N-4ʹ-n-alkyloxy-salicylidene) amino-benzoate]. These compounds are thermally and hydrolytically stable due to inter- or intramolecular hydrogen bonding and exhibit columnar (B1) phases. The phases have been characterised by thermal microscopy and differential scanning calorimetry. A representative example has also been characterised by X-ray diffraction.
Acknowledgements
This research was supported by Department of Atomic Energy (DAE), Department of Science and Technology (DST), Defence Research and Development Organization (DRDO), Naval Research Board and Development (NRBD) and University Grants Commission (UGC), India.