Synthesis and Mesogenic Properties of Liquid Crystals Based on Cholesterol and Cinnamic Acid Derivatives
摘要:
A group of new mesomorphic compounds with cholesterol-based, which have derivative of the cinnamic acid, with different lengths of terminal alkoxy chains, are synthesized and characterized. The mesomorphic properties were investigated by DSC and POM. All target compounds showed a cholesteric phase. For 12-TC and 14-TC besides a cholesteric phase, also revealed a SmA* phase. The experimental results demonstrated that with the increase in the terminal chain lengths, the thermal stability of the smectic mesophases of these liquid crystals was increased, and these compounds shows brilliant color changes in the temperature ranges of cholesteric phase.
and their hypolipidemicactivities were evaluated in a screening system with rats. Cinnamic acids, alpha-methylcinnamic acids, and their various esters with a higher p-alkoxy substituent were found to possess hypolipidemicactivities higher than or comparable to that of clofibrate. The proper length (C12--C16) and the para position of the alkoxy substituent seem to be essential for activity. Chloroethyl
Mesomorphism and flexibility of alkyl chains in chalcone esters
作者:N. R. Muniya、V. R. Patel
DOI:10.1080/15421406.2016.1221989
日期:2016.10.12
Schlieren. Cr-N/I transitioncurve adopts a zigzag path in a normal manner with overall descending behaviors. The N-I transitioncurve exhibits a sharp and shorter odd-even effect from C3 to C6 and it diminishes from and beyond C6 for higher homologs of longer n-alkyl chain (R) in more or less or negligible deviating manner from normal descending tendency. Thermal stability for the nematic is 116.4°C and
The effect of geometrical shape and molecular rigidity on mesomorphism
作者:Priya K. Patel、R. R. Shah
DOI:10.1080/15421406.2016.1190509
日期:2016.9.21
nonlinear homologousseries RO‒C6H4‒CH˭CH‒COO‒C6H4 (meta) ‒CO‒CH˭CH‒C6H4‒OC12H25(n) (para) consisting of three phenyl rings, two central bridges ‒CH˭CH‒COO‒ and ‒CO‒CH˭CH‒ as well as ‒OR and ‒OC12H25(n) as flexible and constant terminal end groups respectively. The object in view is aimed to understand and establish the effect of molecularstructure on LC properties of nonlinear inverted “V” shaped
Synthesis and Evaluation of a Novel Liquid Crystalline Homologous Series: α-4-[4′-<i>n</i>-Alkoxy Cinnamoyloxy] Benzoyl-β-3″,4″-Dimethoxy Phenyl Ethylenes
作者:D. M. Suthar、A. A. Doshi、A. V. Doshi
DOI:10.1080/15421406.2013.785812
日期:2013.8
phase diagram behave in a normal manner. An odd–even effect is observed for the N-I transition curve. The textures of the nematic phase are of the threaded or Schlieren type. Mesomorphic–isotropic transition temperatures range from 152°C to 178°C. The nematogenic phase length varies between 24°C and 51°C. The nematic thermal stability is 163.1°C. Thus, the novel homologousseries is entirely nematogenic
Study of a new homologous series of liquid crystals: Isopropyl-p-(p<sup>/</sup>-n-alkoxy cinnamoyloxy) cinnamates
作者:B. B. Jain、U. H. Jadeja、V. S. Sharma、R. B. Patel
DOI:10.1080/15421406.2015.1073567
日期:2016.1.22
homologue, and follows a zigzag path of rising and falling values as the series is ascended. Nematic–isotropictransition curve shows descending tendency as series is ascended in a normal manner with exhibition of odd-even effect. Smectic mesophase does not appear even in the monotropic condition. Phase transitiontemperatures are determined by hot stage polarizing microscope. Analytical data support