Dipole architecture of molecules and mesomorphic behavior of liquid crystals with rigid T-shaped mesogenic fragment
摘要:
A number of liquid crystalline polyesters having a rigid T-shaped mesogenic fragment and differing in dipole architecture were synthesized and examined by polarizing optical microscopy, differential scanning calorimetry, and IR and (1)H NMR spectroscopy. The thermal stability of the mesophase in the given series of compounds was shown to increase with extension of arms in the T-shaped mesogenic fragment, as well as on replacement of the terminal ester groups (COOAlk) therein by ether moieties (OAlk). Such replacement also enhances smectogenic properties.
Synthesis of Y-Shaped Liquid Crystals and the Influence of Their Structure on the Phase Behavior
作者:Vjacheslav V. Zuev
DOI:10.1080/15421400902841247
日期:2009.8.6
A series of the Y-shaped liquid crystalline (LC) materials based on central 1,2,4-benzenetricarboxylic core was synthesized with variation of the arm length (two or three para-linked phenyl rings) in the Y-shaped mesogen and their dipole architecture (ether or ester terminal and linked groups). Our results indicate that main relationships between molecular structure and mesomorphic behavior well known for the calamitic LC are valid for the Y-shaped compounds too. Smectic mesophases might be obtained by lengthening the mesogen with an additional aromatic core in the arm or with an alkyl chain at the tail. The substitution of the alkoxy terminal groups on to alkanoyl also leads to the enhanced smectic behavior of the Y-shaped molecules.
Dipole architecture of molecules and mesomorphic behavior of liquid crystals with rigid T-shaped mesogenic fragment
作者:V. V. Zuev
DOI:10.1134/s107036320808015x
日期:2008.8
A number of liquid crystalline polyesters having a rigid T-shaped mesogenic fragment and differing in dipole architecture were synthesized and examined by polarizing optical microscopy, differential scanning calorimetry, and IR and (1)H NMR spectroscopy. The thermal stability of the mesophase in the given series of compounds was shown to increase with extension of arms in the T-shaped mesogenic fragment, as well as on replacement of the terminal ester groups (COOAlk) therein by ether moieties (OAlk). Such replacement also enhances smectogenic properties.