作者:Abhijit Sarkar、Satya S. Talwar
DOI:10.1246/bcsj.72.859
日期:1999.4
Diynes with heteroaromatic sidegroups directly linked to the acetylenic backbone were found to show liquid crystalline behaviour upon heating. Thus, 1,4-di(2-thienyl)-1,3-butadiyne, 1,4-di(3-thienyl)-1,3-butadiyne, 1,4-di(3-benzo[b]thienyl)-1,3-butadiyne, 1-(3-quinolyl)-4-(2-thienyl)-1,3-butadiyne, 1-(3-quinolyl)-4-(3-thienyl)-1,3-butadiyne, and 5-(2-thienyl)-2,4-pentadiyne-1-ol were investigated for their thermal behavior. These diynes also underwent polymerization in their liquid crystalline state, although the polymers so formed did not show liquid crystalline behavior. It was found that the S-atom of the heteroaromatic moieties tends to play a role in making the diynes show liquid crystalline behavior. Differential scanning calorimetry, thermogravimetric analysis and hot stage microscopy were used to investigate the liquid crystalline nature of the diynes. All of them showed a nematic liquid crystalline phase upon annealing, whereas smectic phase was totally absent.
直接连接到炔烃主链上的杂芳香侧基二炔在加热时表现出液晶行为。因此,对1,4-二(2-噻吩基)-1,3-丁二炔、1,4-二(3-噻吩基)-1,3-丁二炔、1,4-二(3-苯并[b]噻吩基)-1,3-丁二炔、1-(3-喹啉基)-4-(2-噻吩基)-1,3-丁二炔、1-(3-喹啉基)-4-(3-噻吩基)-1,3-丁二炔和5-(2-噻吩基)-2,4-戊二炔-1-醇的加热行为进行了研究。这些二炔在液晶态下也经历了聚合反应,尽管形成的聚合物并没有显示出液晶行为。研究发现,杂芳香基团的S原子倾向于在使二炔表现出液晶行为中发挥作用。差示扫描量热法、热重分析法和热台显微镜被用于研究这些二炔的液晶性质。它们在退火后都显示出向列型液晶相,完全不出现层列型相。