Supramolecular Self-Assembled Entities Based On Hydrogen Bonding Of Hydrazide And Terpyridine-Metal Coordination

With the development of science, our understanding of chemistry also goes gradually into depth. Modern chemistry has risen from the previous three classical chemical bonds(covalent bonds, ionic bonds, metallic bonds) based on molecular chemistry to the level of supramolecular chemistry. One of the pioneers of supramolecular chemistry, a famous French supramolecular chemist, professor Lehn, clearly put forward the concept of supramolecular chemistry in 1978. He believes that the relationship between from molecular chemistry to supramolecular chemistry and intermolecular interactions, is just as that between from atoms to molecules and covalent bond. The chemistry based on covalent bond and molecules, is known as molecular chemistry; While the chemistry based on intermolecular bonds, and preorganized complex system assembled from two or more molecules through intermolecular interactions, is defined as supramolecular chemistry, also called “the chemistry beyond molecule”. Molecular recognition is foundation of supramolecular chemistry. While, self-assembly is an important means. The construction of supramolecular polymers and supramolecular capsules through self-assembly are two hot research fields in supramolecular chemistry. The research of this thesis involves these two aspects.In the first part of this thesis, we successfully constructed a supramolecular polymer by the cooperative hydrogen bonding and metal-ligand coordination. Through the design of synthetic route, we introduced terpyridine group to the 1-position of benzene ring and two hydrazide units to the 3, 5-position. Through the hydrogen bonding of the hydrazide motifs, it can self-assemble into a cyclic hexamer structure, with six terpyridine groups at the vertices. Upon addition of metal ions, due to terpyridine and metal ion coordination, the cyclic hexamers future self-assembled into a supramolecular polymer network structure. The self-assembly was investigated through nuclear magnetic resonance(NMR), UV-Vis absorption spectroscopy and scanning electron microscopy(SEM).In the second part of this thesis, we constructed a supramolecular capsule from Calix[4]resorcinarene-based Cavitand through metal-ligand coordination. We introduced four terpyridine groups at the wider rim of the cavitand. By addition of metal ions, it self-assembled into a supramolecular capsule through metal-ligand coordination. The encapsulation of guests was also explored.