Defined halogen bond receptors for polymeric architectures: Adaption of behavior in solution as tool to create new functional materials

选择性阴离子结合位点的设计是超分子化学中最重要的领域之一，它能够检测、结合和运输相关的阴离子。虽然基于氢键的阴离子检测已经建立，但卤素键选择性阴离子识别的潜力直到最近才实现。与氢键相比，强相关的卤素键表现出更强的取向偏好，对结合的共价贡献更高，与刘易斯碱伙伴的相互作用更强，这使得构建高选择性阴离子结合位点成为可能。光环-1,2,3-三唑和光环-1,2,3-三唑具有高刘易斯酸性卤素原子，能够建立强卤素键。由于这些杂环的简单和模块化合成，卤素键可以很容易地实现到各种不同的体系中。本课题的研究目的是利用简便、模块化的方法合成卤代1,2,3-三唑和卤代1,2,3-三唑，以开发卤代键的巨大潜力。具体的研究内容包括以下子课题（1 ~ 5）：1)通过对阴离子结合位点进行特异性修饰，研究不同参数对阴离子的咬角、卤素键给体之间的间隔、吸电子基团以及体系预组织的影响。2)将钌（II）配合物与阴离子结合侧结合，构建低检出限的选择性阴离子传感器。3)利用协同效应，设计出对不同离子对具有高选择性和高结合强度的离子对受体。4)卤素键相对于类似的氢键体系具有更高的方向性和阴离子亲和性，有望设计出高效的有机催化剂。halo-1,2,3-三唑的模块化合成允许手性部分的简单整合，这反过来又允许构建非常有趣的对映选择性反应催化剂。5)由于卤素键牢固但不稳定，因此计划在自修复材料中的潜在应用。卤素键在阴离子识别中的应用是目前研究的热点，具有巨大的应用潜力。本研究旨在开发新的卤素键供体，以设计新的阴离子传感器、有机催化剂和功能材料。

The design of selective anion binding sites, which enable a detection, binding and transport of relevant anions, is one of the most important fields in supramolecular chemistry. While anion detection based on hydrogen bonds is well established, the potential of halogen bonds for selective anion recognition was only realized very recently. In contrast to the hydrogen bond, the strongly related halogen bond exhibits a stronger orientational preference, a higher covalent contribution to the binding as well as a stronger interaction with a Lewis-basic partner, which enables the construction of highly selective anion binding sites.Halo-1,2,3-triazoles and halo-1,2,3-triazoliums feature highly Lewis-acidic halogen atoms that are capable of establishing strong halogen bonds. Owing to the facile and modular synthesis of these heterocycles, the halogen bond can be readily implemented into a variety of different systems. The research described in this proposal aims at exploiting the great potential of halogen bonds by making use of the facile and modular synthesis of halo-1,2,3-triazoles and halo-1,2,3-triazoliums. In more detail, the following sub-projects (1 to 5) will be investigated: 1) By the help of specific modifications on the anion binding site, the effect of different parameters, namely the bite angle to the anion, the spacer between the halogen-bond donors the electron-withdrawing group as well as the preorganization of the system, will be studied.2) By combining a ruthenium(II) complex with an anion binding side, selective anion sensors with low detection limits will be constructed.3) By exploiting cooperative effects, ion-pair receptors that exhibit high selectivity and binding strength for different ion pairs will be designed. 4) The higher directionality as well as the higher anion affinities of halogen bonds relative to analogous hydrogen-bond-based systems is expected to enable the design of highly efficient organo-catalysts. The modular synthesis of halo-1,2,3-triazoles allows a simple integration of chiral moieties, which, in turn, allows the construction of highly interesting catalysts for enantioselective reactions. 5) Since halogen bonds are strong but labile, the potential application in self-healing materials is planned.The application of the halogen bond for anion recognition is currently a hot topic and offers an immense potential. This research described herein aims at developing new halogen bond donors in order to design new anion sensors, organo-catalysts as well as functional materials.