Size-Selective Recognition by a Tubular Assembly of Phenylene鈥揚yrimidinylene Alternated Macrocycle through Hydrogen-Bonding Interactions

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• 作者：Duoduo Xiao ; Dengqing Zhang ; Beihua Chen ; Dahai Xie ; Yunjie Xiang ; Xianying Li ; Wusong Jin
• 刊名：Langmuir
• 出版年：2015
• 出版时间：October 6, 2015
• 年：2015
• 卷：31
• 期：39
• 页码：10649-10655
• 全文大小：468K
• ISSN：1520-5827

文摘

Study of artificial tubular assemblies as a useful host scaffold for size-selective recognition and release of guest molecules is an important subject in host鈥揼uest chemistry. We describe well-defined self-assembled nanotubes (NT_6mer) formed from 蟺-conjugated m-phenylene鈥損yrimidinylene alternated macrocycle 1_6mer that exhibit size-selective recognition toward a specific aromatic acid. In a series of guest molecules, a size-matched trimesic acid (G3) gives inclusion complexes (NT_6mer鈯?b>G3) in dichloromethane resulting in an enhanced and red-shifted fluorescence. ¹H nuclear magnetic resonance (NMR) titration experiments indicated that the complex was formed in a 1:1 molar ratio. Density functional theory (DFT) calculations and the binding constant value (K = 1.499 脳 10⁵ M^鈥?) of NT_6mer with G3 suggested that the complex involved triple hydrogen-bonding interactions. The encapsulated guest G3 molecules can be readily released from the tubular channel through the dissociation of hydrogen bonding by the addition of a polar solvent such as dimethylsulfoxide (DMSO). In contrast, 1_6mer could not form self-assembled nanotubes in CHCl₃ or tetrahydrofuran (THF) solution, leading to weak or no size-selective recognizability, respectively.