Charge-Based Assemblies Comprising Planar Receptor-Anion Complexes with Buiky Alkylammonium Cations
Charge-Based Assemblies Comprising Planar Receptor-Anion Complexes with Buiky Alkylammonium Cations
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包含具有丁基烷基铵阳离子的平面受体-阴离子复合物的基于电荷的组件
DOI：
10.1002/chem.201104066
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
Hiromitsu Maeda
中科院分区：
文献类型：
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作者：
Bin Dong;Yoshitaka Terashima;Yohei Haketa;Hiromitsu Maeda
在适当设计的带电物质（离子）之间的相互作用导致了各种状态的电荷基材料，如单晶[1]和离子液体b[2]另一方面，离子液晶作为一类极具吸引力的电荷基软材料受到了极大的关注。[3,4]然而，构建具有阳离子和阴离子适当排列的电荷基组件作为软材料是具有挑战性的。在组件中引入平面带电组件将有助于解决这一问题。与阳离子相反，平面阴离子不容易合成，因为它们必须含有过量的离域电子以防止亲电攻击。二吡啶二酮的硼配合物（例如，1和2，图1a）可以通过与各种阴离子结合提供平面受体-阴离子配合物，作为电荷基组装的潜在构建块。[5,6]在本研究中，受体-阴离子配合物作为平面阴离子与反阳离子结合制备了多种超分子组装体。例如，1通过交替堆叠1·ClÀ和反阳离子，形成固态柱状电荷-电荷组件，如大块的四丙基铵（TPA+；图1b，左）[5a]和平面的4,8,12 -三丙基- 4,8,12 -三氮杂三角铵（(TATAC3)+）阳离子。[6a]此外，与添加ClÀ作为体积较大的四丁基铵（TBA+）盐后，由含有2的辛烷凝胶转变为溶液相反，[5a]通过添加ClÀ作为平面(TATAC3)+盐，凝胶转变为基于电荷组装的另一种凝胶材料。[6a]在分散的离子对和这些盐的组装中观察到的不同状态是由于溶液中2·ClÀ和反阳离子TBA+和(TATAC3)+之间的相互作用强度不同。然而，在没有溶剂的情况下发生的条件可以帮助创建包含大块阳离子的电荷基组件，如在1·ClÀ-TPA +的固态电荷-电荷组件中观察到的那样。[5a]根据一项理论研究（图1b，中、右），该组件是通过使用带正电荷和带负电荷的组件之间的静电相互作用构建的本文对平面受体-阴离子配合物2·ClÀ与各种四烷基铵阳离子(nmMe4ÀmN+（(CnH2n+ 1) mMe4ÀmN+: m在1 - 4范围内，图1c）的组装进行了深入研究平面的2·ClÀ和块状的nmMe4ÀmN+结合形成了基于2·ClÀ-nmMe4ÀmN +的电荷基组装体，其填料结构由阳离子根据长烷基链数(m)和长度(n)等参数进行调节。2·ClÀ-nmMe4ÀmN +离子对在1,4 -二氧六环等溶剂中结合，形成红色沉淀。它们的组成经1HNMR光谱和元素分析证实。值得一提的是，2·ClÀ-nmMe4ÀmN +是稳定的、不吸湿的结晶固体，与吸湿性nmMe4ÀmNCl形成鲜明对比。此外，nmMe4ÀmNCl在整个可见光区域都是光学透明的；[a]董b .博士，Terashima Y., Haketa Y.博士，前田H.博士，立命馆大学药学院525-8577（日本）传真：（+ 81）777-561-2659 E-mail: maedahir@ ph. ritsumei。本文的支持信息可在WWW的http://dx下获得。doi。org/10.1002/chem。201104066.
Interactions between appropriately designed charged species (ions) result in charge-based materials in various states, such as single crystals [1] and ionic liquids.[2] On the other hand, ionic liquid crystals have received significant attention as a fascinating class of charge-based soft materials.[3, 4] However, it is challenging to construct charge-based assemblies as soft materials with the appropriate arrangement of both cations and anions. The introduction of planar charged components into the assemblies would help to solve this issue. In contrast to cations, planar anions are not easy to synthesize because they must contain excess delocalized electrons to prevent an electrophilic attack. As potential building blocks for charge-based assemblies, boron complexes of dipyrrolyldiketones (eg, 1 and 2, Figure1a) can provide planar receptor–anion complexes by association with various anions.[5, 6] In this study, the receptor–anion complexes were used as planar anions to fabricate a variety of supramolecular assemblies in combination with counter cations. For example, 1 formed solid-state columnar charge-by-charge assemblies by alternately stacking 1· ClÀ and counter cations, such as bulky tetrapropylammonium (TPA+; Figure 1 b, left)[5a] and planar 4, 8, 12-tripropyl-4, 8, 12-triazatriangulenium ((TATAC3)+) cations.[6a] Furthermore, in contrast to the transition to a solution from an octane gel comprising 2 after the addition of ClÀ as a bulky tetrabutylammonium (TBA+) salt,[5a] the gel was transformed to another gel material based on charge-by-charge assemblies by the addition of ClÀ as a planar (TATAC3)+ salt.[6a] The different states observed in the dispersed ion pairs and the assemblies by these salts are due to the varying strengths of the interactions between 2· ClÀ and counter cations, TBA+ and (TATAC3)+, respectively, in solution. However, the conditions that occur in the absence of solvents can help to create charge-based assemblies comprising bulky cations as observed in the solid-state charge-by-charge assembly of 1· ClÀ–TPA+.[5a] The assembly is constructed by using the electrostatic interactions between the positively and negatively charged components, as suggested by a theoretical study (Figure1b, middle and right).[7] Herein, the assemblies of the planar receptor–anion complex 2· ClÀ with various tetraalkylammonium cations, nmMe4ÀmN+((CnH2n+ 1) mMe4ÀmN+: m is in the range 1–4, Figure 1c), are thoroughly investigated.[8] The combination of planar 2· ClÀ and bulky nmMe4ÀmN+ results in chargebased assemblies on the basis of 2· ClÀ–nmMe4ÀmN+, for which the packing structures were modulated by the cations according to parameters, such as the number (m) and the length (n) of long alkyl chains. Ion pairs 2· ClÀ–nmMe4ÀmN+ were prepared as red precipitates by the combination of 2 and nmMe4ÀmNCl in solvents, such as 1, 4-dioxane. Their compositions were confirmed by 1HNMR spectroscopy and elemental analysis. It is worth mentioning that 2· ClÀ–nmMe4ÀmN+ are stable, nonhygroscopic, crystalline solids, which are in sharp contrast to the hygroscopic nmMe4ÀmNCl. In addition, nmMe4ÀmNCl are optically transparent in the entire visible region; however,[a] Dr. B. Dong, Y. Terashima, Dr. Y. Haketa, Prof. Dr. H. Maeda College of Pharmaceutical Sciences Institute of Science and Engineering Ritsumeikan University Kusatsu 525–8577 (Japan) Fax:(+ 81) 77-561-2659 E-mail: maedahir@ ph. ritsumei. ac. jp Supporting information for this article is available on the WWW under http://dx. doi. org/10.1002/chem. 201104066.