The synthesis and mesomorphic properties of two series of compounds viz.(S)-(+)-4-(1-methylheptyloxy)phenyl 4′-(6″-alkoxypyridine-3-carbonyloxy)benzoates and (S)-(+)-l-methylheptyl4-[4′-(6″-alkoxypyridine-3-carbonyloxy)benzoyloxy]-benzoates are reported; the homologues of the former series exhibit smectic A and smectic C* phases while the derivatives of the latter series show rich polymesomorphism including the antiferroelectric phase. The mesophases have been characterised by using optical polarising microscopy and differential scanning calorimetric methods. Some physical properties such as the spontaneous polarisation, helical pitch, tilt angle and relative permittivity of two derivatives have also been investigated.
报告了两个系列化合物的合成和介形性质,即(S)-(+)-4-(1-甲基庚基氧基)苯基4'-(6"-烷氧基
吡啶-3-羰基氧基)
苯甲酸酯和(S)-(+)-l-甲基庚基4-[4'-(6"-烷氧基
吡啶-3-羰基氧基)苯甲酰氧基]
苯甲酸酯;前者的同系物表现出层状A相和层状C*相,而后者的衍
生物则表现出丰富的多晶型性,包括反
铁电相。使用光学偏振显微镜和差示扫描量热法对介形相进行了表征。还研究了两个衍
生物的自发极化、螺旋间距、倾斜角和相对介电常数等一些物理性质。