Effects of isocyanide substituents on the mesogenic properties of halogeno(isocyanide)gold complexes: calamitic and discotic liquid crystals
作者:Silverio Coco、Pablo Espinet、José M. Martín-Alvarez、Anne-Marie Levelut
DOI:10.1039/a604258i
日期:——
The liquid crystal behaviour of linear
[AuX(CNC
6
H
4
OC
n
H
2n
+1
)] (X=halogen) complexes is tuned by systematically changing the
structure of the isocyanide ligand. The changes studied are lateral
fluorination at the 2- and 3-positions of the phenyl ring and modification
of the rod-like structure of the complexes by addition of two alkoxy
chains at themeta positions. None of the free isocyanides used
here are liquid crystals, but all the gold complexes prepared display
mesomorphic properties, except iodo(2-fluoro-4-butoxyphenyl
isocyanide)gold(i). The (2- and (3-fluorophenyl isocyanide)gold(i)
complexes show smectic A mesophases, except the 2-fluoro derivative with
n=6, which shows a nematic phase, while the
(3,4,5-trialkoxyphenyl isocyanide)gold compounds display columnar
hexagonal phases at room temperature.
通过系统地改变异氰酸配体的结构,调整了线性 [AuX(CNC 6 H 4 OC n H 2n +1 )] (X=卤素)配合物的液晶行为。所研究的变化是在苯基环的 2 位和 3 位进行横向氟化,以及通过在它们的eta 位置添加两条烷氧基链来改变配合物的杆状结构。这里使用的游离异氰酸酯都不是液晶,但除了碘(2-氟-4-丁氧基苯基异氰酸酯)金(i)之外,制备的所有金络合物都显示出介形特性。除了 n=6 的 2-氟衍生物显示出向列相外,(2-和(3-氟苯基异氰酸酯)金(i)复合物显示出 Smectic A 介相,而(3,4,5-三烷氧基苯基异氰酸酯)金化合物在室温下显示出柱状六方相。