Design, synthesis, and characterisation of symmetrical bent-core liquid crystalline dimers with diacetylene spacer
Design, synthesis, and characterisation of symmetrical bent-core liquid crystalline dimers with diacetylene spacer
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DOI：
10.1080/02678292.2013.805829
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发表时间：
2013-08
期刊：
影响因子：
2.2
通讯作者：
Lanying Zhang;Qi-Kai Zhang;Yu-dong Zhang
中科院分区：
文献类型：
--
作者：
Lanying Zhang;Qi-Kai Zhang;Yu-dong Zhang
通过Sonagashira偶联反应成功合成了两种新型对称弯曲核液晶二聚体（B-DA 4和B-DA 12），它们带有二乙炔间隔基和不同的末端烷基链。这些二聚体的分子结构通过1H核磁共振（NMR）、傅立叶变换红外光谱（FT-IR）、拉曼光谱、质谱和元素分析来确认。通过热重分析（TGA）、差示扫描量热法（DSC）、偏光显微镜（PLM）和小角X射线散射（SAXS）表征了它们的热稳定性和液晶性质。结果表明，二乙炔基团可以在远离热分解的约260°C下热聚合。二聚体表现出单变相行为和典型的层状结构相与长程有序的长度尺度约为6.3 nm的观察。上述结果提供了一个有前途的机会，设计聚丁二炔纳米线的热，紫外线照射，或扫描隧道显微镜（STM）尖端诱导聚合。
Two new symmetrical bent-core liquid crystalline dimers (B-DA4 and B-DA12) bearing diacetylenes spacer and different terminal alkyl chains were successfully synthesised via Sonagashira coupling reaction. The molecular structures of these dimers were confirmed by 1H nuclear magnetic resonance (NMR), Fourier transform-infrared spectroscopy (FT-IR), Raman spectroscopy, mass spectrometry, and elemental analysis. Their thermal stability and liquid crystalline properties were characterised by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), polarised light microscopy (PLM), and small-angle X-ray scattering (SAXS). Results showed that the diacetylene group may be thermal polymerised at about 260°C far from thermal decomposition. The dimers exhibited monotropic phase behaviour and typical layered-structure phase with long-range order on a length scale of about 6.3 nm was observed. The results mentioned above offer a promising opportunity to design polydiacetylene nanowires by thermal, UV irradiation, or scanning tunnelling microscope (STM) tip-induced polymerisation.