Molecular Crystals and Liquid Crystals, Vol.625, No.1, 72-80, 2016
Mesomorphic dependence on molecular rigidity by central bridge and homo-hetero ring systems
A novel homologous series of thermotropic derivatives containing a heterocyclic ring was synthesized and studied with a view to understanding and establishing a relation between liquid crystal (LC) properties and the molecular structure of chalconyl derivative in general. The series comprises 12 homologues, of which smectogenic LC property commences from the decyloxy (C-10) homologue and continues for C-12, C-14, and C-16 homologues. Homologues C-1 to C-8 are non-liquid crystals. Exhibition of nematogenic mesophase is totally absent. Transition and melting temperatures were determined by an optical polarizing microscope equipped with a heating stage. Spectral and analytical data confirmed the molecular structures of homologues. The textures of smectic mesophase are A or C, and are determined by a miscibility method. The average thermal stability of the smectic phase is 113.57 degrees C. The mesogenic phase length ranges between 4.1 degrees C and 11.1 degrees C. Thus, it is a middle-ordered melting-type series of shorter range of liquid crystallinity with absence of nematogenic character. Some LC properties of the present series are compared with a structurally similar known homologous series.