Dependence of mesomorphism on molecular rigidity of chalconyl liquid crystals with two phenyl rings

作者：Sharma Vinay S; Patel R B^*

来源：Molecular Crystals and Liquid Crystals, 2016, 637(1): 19-27.

DOI：10.1080/15421406.2016.1190502

• Chalcones
• liquid crystals
• monotropy
• nematic
• smectic

A novel homologues series: RO-C6H4 center dot CH=CH center dot CO center dot C6H4 center dot OC16H33 (n) (meta) of chalcones with two phenyl rings is synthesized and studied with a view to understanding and establishing the relationship between molecular structure and mesogenic behavior. The series consists of 13 homologues (C-1 to C-18). Mesomorphism commences from the second member of the series. C-2 to C-6 homologues are enantiotropicnematic and the rest of the homologues (C-7 to C-8) are monotropicnematic plus monotropicsmectic. C-1 homologue is nonmesogenic. Transition temperatures were determined by an optical polarizing microscope (POM) equipped with a heating stage. Textures of nematic and smectic phases are threaded, Schlieren or smectic-A, respectively, as judged directly from the heating top of microscopic observations. Thermal, analytical and spectral data confirms the molecular structures. Thermal stabilities for smectic and nematic are few (1 or 2 degrees C) degrees and 72.6 degrees C, respectively. The mesophase lengths are relatively shorter with low mesomorphic transition temperatures (44.0 degrees C to 85.0 degrees C).

• 出版日期2016