ABSTRACT
Calamitic liquid crystalline amides 1–3 were synthesized and their thermodynamic behaviors were investigated. Bent-rod shaped compound 1 exhibited a usual smectic C phase. On the other hand, in the case of straight-rod compound 2, two kinds of smectic C phases (SmCx and SmCy) were observed above the crystal phase. Although SmCy phase belonged to general smectic C phases, SmCx phase exhibited very sharp lines in its schlieren textures. As the packing model of smectic Cx phase, a lateral linear arrangement of the molecules was proposed to explain the difference between these smectic C phases. Additionally, in the case of 3 which has a flexible spacer between its amide group and straight rodlike core, the molecules generated the highly ordered smectic C (3a, SmCx) and a chiral cubic phase (3b).