Effect of alkoxy terminal chain length on mesomorphism of 1,6-disubstituted pyrenebased hexacatenar liquid crystals: columnar phase control
Effect of alkoxy terminal chain length on mesomorphism of 1,6-disubstituted pyrenebased hexacatenar liquid crystals: columnar phase control
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DOI：
10.1016/j.tet.2014.05.111
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发表时间：
2014-08-26
期刊：
影响因子：
2.1
通讯作者：
Yasutake, Mikio
中科院分区：
文献类型：
--
作者：
Hirose, Takuji;Takai, Hiroaki;Yasutake, Mikio
本文报道了六种1，6-二取代芘基十六碳链液晶1（n）（n=8-18）的合成和介相转变行为。它们是由带有三烷氧基苯甲酰基的2-溴噻吩和1，6-二乙炔基芘通过Sonogashira偶联反应合成的。通过差示扫描量热法和偏光显微镜研究了其相变行为;观察到一些中间相进展，I-Col/I-X-Col和Col-Sm，其中X是光学各向同性但未鉴定的相。通过X射线衍射分析了Col（r）、Col（h）和Sm相的结构，并研究了末端烷氧基链长对介晶性的影响。(C)2014爱思唯尔有限公司版权所有。
Synthesis and mesophase-transition behaviors of six 1,6-disubstituted pyrene-based hexacatenar liquid crystals 1(n) (n=8-18) are reported here. They were synthesized by the Sonogashira coupling between 1,6-diethynylpyrene and 2-bromothiophene bearing a trialkoxybenzoyl group. The phase-transition behavior was studied by differential scanning calorimetry and polarized optical microscopy; a few mesophase progressions, I-Col/I-X-Col and Col-Sm, were observed, where X was an optically isotropic but un-identified phase. The structures of Col(r), Col(h), and Sm phases were analyzed by the X-ray crystallography, and the effect of the terminal alkoxy chain length on the mesomorphism was evaluated. (C) 2014 Elsevier Ltd. All rights reserved.