Synthesis, Structure And Conformation Of Terphenylene-Derived Oxacalixaromatics And Azacalixaromatics

Calix[n]arenes and their derivatives have received great research interest owing to their easy synthesis, well-defined conformational and cavity structures, and the abilities to act as host molecules for wide variety of neutral or charged species. The functionalization of calixarene scaffolds can not only promote the development of supramolecular chemistry, but also provide a wide application prospect in life science, environmental science, pharmacy, medical technology, nanometer material and other fields.The traditional calix[4]arenes using methylene as bridging elements, which have been extensively studied, including the synthesis, derivatization, molecular recognition and so on. With the rapid development of calixarenes in the field of supramolecular chemistry, a number of researchers are changing their focus on heterocalix[n] aromatics, in which the methylene bridges are replaced by oxygen, nitrogen or sulfur atoms respectively. By the introduction of heteroatoms and the changes of the size and structure of aromatic ring, the size and shape of the cavity structures in heterocalix[n]aromatics can be modulated and their selective guest encapsulation properties can be realized. In this thesis, we introduced m-terphenylene in the calix[4]arene scaffold and replaced the methylene bridges with the oxygen and nitrogen atom in order to obtain a series of expanded heterocalix[4]aromatics. The structures and conformations of these compounds are disscussed.1. The reported syntheses of m-terphenylene-based diol or diamine were carried out according to a modified literature method using p-tert-butylaniline as the starting material. Four m-terphenylene-based diols and diamines have been obtained.2. A series of heterocalix[2]arene[2]terphenylenes were synthesized via one pot or sequential nucleophilic aromatic substitution reactions of terphenylene-based diol or diamine with electron-deficient meta-dihalogenated benzene and heterocycles, such as1,5-difluoro-2,4-dinitrobenzene and cyanuric chloride. All new compounds were characterized by elementary analysis,1H-NMR,13C-NMR, HR-MS and infrared spectroscopic methods, and some of structures were also confirmed by X-Ray single crystal diffraction analysis. We found that the heterocalix[2]arene[2] terphenylenes possess more flexible conformation and larger cavity compared with the traditional heterocalix[4]arenes, and several compounds of this class have the ability to capture small guest molecules, such as chloroform, ethyl acetate and DMSO.In this work, eighteen new heterocalix[4]aromatics have been synthesized, and ten of them were structurally confirmed by X-ray single crystal diffraction analysis.