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

阴离子选择性结合位点的设计是超分子化学的重要研究方向之一，它可以实现阴离子的检测、结合和转运。虽然基于氢键的阴离子检测已经很好地建立，但是卤键用于选择性阴离子识别的潜力直到最近才被认识到。与氢键相比，卤键具有更强的取向性、更高的共价键贡献以及更强的与路易斯碱性配体的相互作用，这使得卤代-1，2，3-三唑和卤代-1，2，3-三唑具有高度路易斯酸性的卤原子，能够建立强的卤键。由于这些杂环的容易和模块化合成，卤键可以容易地实施到各种不同的系统中。本研究的目的是利用卤代-1，2，3-三唑和卤代-1，2，3-三唑鎓的简便和模块化合成来开发卤键的巨大潜力。更详细地说，将调查以下分项目（1至5）：1）通过对阴离子结合位点的特定修饰，研究了不同参数，即对阴离子的咬合角、卤素键供体之间的间隔基、吸电子基团以及系统的预组织的影响，将研究。2）通过将钌（II）配合物与阴离子结合侧结合，将构建具有低检测限的选择性阴离子传感器。3）通过利用协同效应，将设计对不同离子对表现出高选择性和结合强度的离子对受体。4)卤键相对于类似的基于氢键的系统的更高的方向性以及更高的阴离子亲和力预期使得能够设计高效的有机催化剂。卤代-1，2，3-三唑的模块化合成允许手性部分的简单整合，这反过来又允许用于对映选择性反应的高度有趣的催化剂的构建。5)由于卤键是一种强而不稳定的键，因此卤键在自修复材料中具有潜在的应用前景，卤键在阴离子识别中的应用是目前的一个热点，具有巨大的潜力。 本研究的目的是开发新的卤键供体，以设计新的阴离子传感器，有机催化剂以及功能材料。

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.