Study On The Host-Guest Chemistry Based On Pillar[5] Arene And Azastilbene Derivatives And The Related Applications

Supramolecular chemistry is a discipline that studies some relatively weak and reversible non-covalent interactions between molecules,including hydrogen bonding,hydrophobic interactions,metal coordination,π-πstacking and electrostatic interactions.Molecules self-assembled into aggregates with complex order and certain functions under these non-covalent interactions.Host-guest chemistry is an important eye-catching branch in the field of supramolecular chemistry.Macrocyclic compounds are the basic units for constructing various supramolecular structures and materials because of their special host-guest properties.As a new type of macrocyclic hosts,pillararenes has been extensively studied in recent years due to their unique molecular structure and easy functionalization.Pillararenes have been successfully applied to construct various novel supramolecular functional materials and applied in various fields,such as controlled-release of drugs,energy transfer,biomedicine,stimulus responsive materials,self-healing materials.The dissertation mainly includes the following two aspects:In the first part,we chose an azastibene derivative（trans-4,4’-azastilbene）as a neutral guest and investigated the host-guest recognition with 1,4-dimethoxypillar[5]arene（DMP5）.In addition,since trans-4,4’-azastilbene has photosensitivity,we studied the stimuli-responsive behavior of DMP5 and trans-4,4’-azastilbene.In addition,the driving force of host-guest interactions between DMP5 and trans-4,4’-azastilbene was studied by comparing a series of similar neutral guest molecules.Moreover,a photoresponsive polypseudorotaxane was fabricated from the[2]pseudorotaxane formed by DMP5 and azastilbene by coordinating with copper ions.In the second part,a new host-guest recognition motif based on1,4-dimethoxypillar[5]arene and a positively charged azastilbene guest was fabricated.Based on this,we successfully designed and synthesized a new type of AB-type monomer1.Then,the monomer 1 self-assembled into linear supramolecular polymers at relatively high concentrations.Moreover,when Pd²⁺was added,the linear supramolecular polymer was cross-linked to form supramolecular polymer network nel via metal coordination.¹H NMR spectroscopy,viscosity and scanning electron microscopy were utilized to investigate the formation of the supramolecular polymer network gel.