The Construction And Properties Of Novel Covalent Organic Frameworks

Since the pioneering work of Yaghi and co-workers on covalent organic frameworks (COFs) in2005, such kind of novel organic materials have evoked tremendous interest among chemists both in material science and organic synthesis. To date, most studies are focusing on the synthesis of new COF materials and their applications. For example, several kinds of reactions, including the formation of boronate anhydride, boronate ester, borosilicate and borazine; the formation of imine and hydrazine; nitrile cyclotrimerisation have been successfully applied in the synthesis of COFs. Current COFs, however, have limitations over structure stability and functional applications. So it’s highly desirable to explore novel COFs with high stability and particular properties for application, or to find new methods of synthetizing COFs in terms of convenience and efficiency. This thesis is aimed to explore COFs with novel linkage and build COFs with elegant structure from the perspective of dynamic combinatorial chemistry (DCC).In Chapter1, the recent development of COFs and alkyne metathesis reactions are presented. A brief understanding of dynamic combinatorial chemistry and its design concept in building exquisite molecular structure has been stated.In Chapter2, an exploration of building crystalline materials through alkyne metathesis reaction has been presented. We have synthezed a series of materials through different kinds of building blocks.The results showed that the materials were formed by cyclotrimerisation rather than metathesis.In Chapter3, the synthesis of two COFs using three reactants in one pot has been described. It is found that the ratio of mesitylene and dixoane can influence the reaction types, and would finally determine the material structure.