Synthesis and Study of Liquid Crystallinity of Benzoate Derivatives in a Laterally substituted Homologous Series: n-Propyl-o-[p'-n-alkoxy benzoyloxy] benzoates

Doshi, Joshi, Patel
2011 Der Pharma Chemica   unpublished
A homologous series n-Propyl-o-[p'-n-alkoxy benzoyloxy] benzoates was synthesized and studied with a view to understand and establish the effect of benzoate derivatives on liquid crystal behaviour by n-propyl group. Ten homologues were synthesized. Eight homologues showed liquid crystal behaviour while two homologues viz. methyl and ethyl homologues escape from liquid crystal behaviour. Curves of the phase diagram drawn from transition temperatures of the homologues as determined by hot stage
more » ... ined by hot stage polarizing microscope shows normal behaviour with persistence of odd-even effect in nematic-isotopic transition curve. n-Propyl to hexyl, octyl derivatives are enantiotropic nematic, decyl derivative is enantiotropically nematic in addition to smectic character, while dodecyl and tetradecyl derivatives are only enantiotropic smectic. Analytical data support the structure. Liquid crystal properties are compared with structurally similar homologous series. Textures of nematic and smectic mesophase are threaded or schlieren and focal conic fan shaped of smectic A or C respectively.