| Given the multi-dimensional binding sites of tripodal molecule and pillar[5]arene as a new macrocycle and squaramide as a good unit in host-guest recognition, a series of squaramide-based tripodal receptors and squaramidea-functionalized pillar[5]arene have been synthesized. These compounds were applied in the field of anion recognition and neutral organic molecular recognition.This thesis consists of two parts of work as follows, around the squaramide decorated compounds.1. Squaramide-based tripodal receptors for selective recognition of sulfate anionA series of squaramide-based tripodal anion receptors 2-la,b,c have been prepared and their anion binding properties with various inorganic anions were investigated. Single crystal structure of complex 2TBA-[2-1a·SO4] suggested an unusual dimeric encapsulation of SO42- by receptor 2-la with 2:2 binding stoichiometry in solid state, while both 1H NMR titration experiments and DOSY NMR experiments at different concentrations suggested SO42- was encapsulated by receptor 2-la with 1:1 binding stoichiometry in solution. All receptors 2-1a,b,c could selectively encapsulate SO42- via hydrogen bonds over other examined anions.2. Two different squaramide-based pillar [5] arene receptors binding with linear alkyl dicarboxylates and organic acid respectively.A bis-squaramide-functionalized pillar[5]arene has been synthesized and and its binding properties with linear alkyl dicarboxylates in highly polar solvent DMSO were investigated., in which the hydrogen bonding interactions between the bis-squaramide hydrogens and the oxygen of dicarboxylate play an important role in the binding alongside C-H…π interactions. A series of mono-squaramide-functionalized pillar[5]arenes have also been synthesized and and their binding behavior with organic acids were investigated as well.This research offers an insight into the host-guest recognition based on tripodal and pillar[5]arene receptors decorated by squaramide. |
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