Thermotropic properties and molecular packing of discotic tristriazolotriazines with rigid substituents.
Thermotropic properties and molecular packing of discotic tristriazolotriazines with rigid substituents.
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DOI：
10.1002/chem.201400034
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发表时间：
2014-04
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影响因子：
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通讯作者：
Thorsten Rieth;T. Marszalek;W. Pisula;H. Detert
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文献类型：
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作者：
Thorsten Rieth;T. Marszalek;W. Pisula;H. Detert
以三聚氯氰和相应的四唑为原料，通过Huisgen反应合成了三重二烷氧基芳基取代的三唑并三嗪。尽管这些染料显示UV/维斯吸收的负或反向溶剂化变色，但它们的荧光是强正溶剂化变色的。这些分散荧光团在其固态和其宽液晶中间相中也是发射性的。结构研究表明，这些系统的热致性和组织，可以很好地调整的空间位阻需求的芳基。取决于取代基，化合物显示出纯结晶相或在升高的温度下具有特征液晶相的高度复杂的螺旋超结构。改变所连接的芳基的空间需求允许控制圆柱螺旋内的盘排列，这对分子轨道重叠非常重要。
Tristriazolotriazines with a threefold dialkoxyaryl substitution have been prepared by Huisgen reaction of cyanuric chloride and the corresponding tetrazoles. Although these dyes show a negative or inverted solvatochromism of the UV/Vis absorption, their fluorescence is strongly positive solvatochromic. These discotic fluorophores are also emissive in their solid state and in their broad liquid-crystalline mesophase. The structural study indicates that the thermotropic properties and organization of these systems can be well tuned by the steric demand of the aryl groups. Depending on the substituents, the compounds showed either a pure crystalline phase or a highly complex helical superstructure with a characteristic liquid-crystalline phase at elevated temperatures. Changing the steric demand of the attached aryls allowed controlling the discs arrangement within the columnar helix, which is of great importance for the molecular orbital overlap.