Propeller-like hydrogen-bonded banana-melamine complexes inducing helical supramolecular organizations
Propeller-like hydrogen-bonded banana-melamine complexes inducing helical supramolecular organizations
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DOI：
10.1021/ja0585477
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发表时间：
2006-04-05
影响因子：
15
通讯作者：
Sierra, T
中科院分区：
文献类型：
--
作者：
Barberá, J;Puig, L;Sierra, T
本文提出的研究结果显示了一个新的例子，使用液晶和相互作用参与的亚形态状态，以建立复杂的分子组织。我们采用了一种设计策略，其中氢键允许三聚氰胺的pi堆叠倾向和v形分子的横向相互作用能力相结合，这已经通过向列相、近晶相或柱状中间相广泛证明。这种组合解决了柱状排列的形成与固有的螺旋组织。在这项工作中，具有类似香蕉液晶结构的非中形酸和中形v形酸分别以3:1的比例与2,4,6-三胺-1,3,5-三嗪衍生物络合。通过红外和核磁共振技术证实了氢键超分子的形成及其在溶液中的稳定性。DOSY实验使我们能够在溶液中评估配合物的存在及其四聚体组成。所有配合物均表现出介晶生成能力，并通过x射线衍射和CD光谱对其介晶组织进行了研究。结果使我们能够提出一种起源于超分子复合物的螺旋桨状构象的中间相的螺旋柱状模型。
The results of the study presented here show a new example of the use of liquid crystals and the interactions involved in the mesomorphic state to build up complex molecular organizations. We have pursued a design strategy in which hydrogen bonding allows the combination of the pi-stacking tendency of melamine and the lateral interaction capability of V-shaped molecules, which has been extensively demonstrated through nematic, smectic, or columnar mesophases. This combination addresses the formation of columnar arrangements with inherent helical organization. In this work, nonmesomorphic as well as mesomorphic V-shaped acids, with a structure similar to banana liquid crystals, have been complexed to a 2,4,6-triamino-1,3,5-triazine derivative in a proportion 3 to 1, respectively. Hydrogen-bonded supramolecules whose formation and stability in solution have been proven by infrared and NMR techniques have been thus obtained. DOSY experiments have allowed us to assess in solution the presence of the complexes and their tetrameric composition. All the complexes display mesogenic ability, and their mesomorphic organization has been studied by X-ray diffraction and CD spectroscopy. Results allow us to propose a helical columnar model for the mesophase originated from a propeller-like conformation of the supramolecular complexes.