Achiral unsymmetrical four-ring bent-core liquid crystals with a polar fluoro or chloro end substituent: synthesis and characterisation

Achiral unsymmetrical 2-methyl 3-amino-benzoic acid (2,6-substituted toluene)-derived four-ring bent-core liquid crystals with a polar fluoro or chloro substituent at one end and an alkyloxy group (butyl to dodecyl) at the other end have been synthesised by a simple and straightforward synthetic method. The molecular structure characterisation is consistent with the elemental and spectroscopic analysis data. The materials' thermal behaviour and phase characterisation have been investigated by differential scanning calorimetry and polarising optical microscopy. All the compounds exhibit an enantiotropic nematic phase over a wide temperature range.