Mesogenic Schiff base esters with terminal chloro group: Synthesis, thermotropic properties and X-ray diffraction studies

International Journal of Physical Sciences

Sie-Tiong Ha¹ 

关键词: Schiff base ester;    thermotropic properties;    smectic A;    smectic B;    X-ray diffraction.;   

DOI  :  

学科分类：物理（综合）

来源: Academic Journals

【 摘 要 】

A new homologous series of Schiff base esters comprising a terminal chloro substituent was studied. The chloro substituent contributes to the molecular polarizability, thus, affecting intermolecular interactions, hence, resulting in smectic polymorphism. The mesomorphic properties were studied using differential scanning calorimetry, polarizing optical microscopy and temperature-dependent X-ray diffractometry. Whilst then-pentanoyloxy andn-heptanoyloxy derivatives exhibited enantiotropic smectogenic A and B phases, monotropic smectogenic A and Bphases were observed in then-butanoyloxy andn-hexanoyloxy derivatives. Enantiotropic smectogenic A and monotropic smectogenic B phases were observed in then-octanoyloxy ton-hexadecanoyloxy derivatives. The highest member of this series, then-octadecanoyloxy derivative, exhibited an enantiotropic smectogen A phase. The homologous members were compared with structurally related series to establish their chemical structure-mesomorphic behavior relationships.

【 授权许可】

CC BY