Synthesis and Physical Properties of Novel Terphenyl Type Ferroelectric Liquid Crystals
摘要:
A new series of optically active compounds have been prepared using 4.4 ''-terphenyldicarboxylic acid and S-2-alcoxypropanols-1. These ace Sm*C, SmA and N* chemically stable - especially with regard to racemization and UV-light compounds with a snail P-S value, high twisting power and left handedness of helix.
手性氧钒 (IV)、铜 (II) 和钯 (II) β-二酮酸盐显示出室温柱状中间相,该中间相发生铁电转换。所有化合物在室温下均以液晶形式获得,通过差示扫描量热法在-20°C下未检测到结晶或熔化过程。通过光学显微镜、DSC 和 X 射线衍射研究中间相,并确定为矩形柱状 (P21)。观察到的所有化合物的花状纹理使我们推断出分子相对于柱轴的高倾角(约 40°)。圆二色性已证实柱内存在螺旋排列。该结果与介电光谱研究中在低频(约 10 -3 Hz)下发现的所谓柱状模式一致。这些材料的光电响应已通过光电倍增管进行了检查。所获得的结果可以通过考虑在中间相中发现的高倾角的强烈影响来解释。
Ferroelectric Liquid Crystals Containing the Cyano Group
作者:M. Kašpar、H. Sverenyák、V. Hamplová、S. A. Pakhomov、M. Glogarová
DOI:10.1080/10587259508038695
日期:1995.2
A new series of ferroelectric liquid crystals having the cyano group in the mesogenic core and with the terminal group based on O-substitued S-(-)-lactic acid has been synthetized and characterized. The compounds exhibit a broad ferroelectric chiral smectic C mesophase with a high spontaneous polarization.