Azobenzene-containing bent-core liquid crystals: an overview
Azobenzene-containing bent-core liquid crystals: an overview
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DOI：
10.1080/02678292.2016.1175676
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发表时间：
2016-05
期刊：
影响因子：
2.2
通讯作者：
M. Alaasar
中科院分区：
文献类型：
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作者：
M. Alaasar
摘要 偶氮官能化材料因其光致变色性质（即光照射后可逆的反式-顺式异构化）而受到特别关注。同一分子中光敏性和液晶特性的结合使得该材料可用于光学和光电器件。近年来，基于偶氮苯的弯核液晶（BCLC）由于其丰富的介晶性而引起了广泛的关注。本文总结了包含偶氮苯单元的弯核分子及其亚型（即所谓的曲棍球棒分子）的主要研究方向和不同分子结构。此外，还提供了基于偶氮苯的U形分子、氢键弯曲形液晶材料和两种不同类型的光可切换介晶二聚体的一些选定示例。讨论了能够改变此类 BCLC 相行为的横向取代的性质、数量和位置，进而提供有趣的液晶相。最后，总结了这些光敏BCLC在溶液或中间相中在紫外-可见光照射下的异构化过程。图解摘要
ABSTRACT Azo-functionalised materials are of special interest due to their photochromic nature, i.e. reversible trans–cis isomerisation upon photoirradiation. The combination of photosensitivity and liquid crystalline properties in the same molecule allows the material to be exploited for optical and optoelectronic devices. Azobenzene-based bent-core liquid crystals (BCLCs) have attracted considerable attention in recent years due to their rich mesomorphism. In this review, the main research directions and different molecular structures of bent-core molecules incorporating azobenzene unit and its subtype the so-called hockey-stick molecules are summarised. Additionally, azobenzene-based U-shaped molecules, hydrogen-bonded bent-shaped liquid crystalline materials and some selected examples of two different types of photoswitchable mesogenic dimers are provided. The nature, number and position of the lateral substitutions able to modify the phase behaviour of such BCLCs, affording in turn interesting liquid crystalline phases are discussed. Finally, the isomerisation process of these photosensitive BCLCs in solutions or in mesophases under the effect of UV–visible irradiation is summarised. GRAPHICAL ABSTRACT