Studies On Construction And Formation Mechanism Of Supramolecular Aggregates Based On Derivates Of β-Cyclodextrin And Ferrocene

Supramolecular chemistry has been defined as the "chemistry of molecular assemblies and of the intermolecular bond". Combing with the material science, biological science, information technology and nanometer technology, it has been the supramolecular science and has been employed as a vital method to design and prepare new tnaterials and obtain novel properties. Therefore, supramolecular chemistry is believed to be the base of new concept and technology in the 21st century.As an important aspect of self-assembly, host-guest interaction is one of main components of supramolecular chemistry, crown ether, Cyclodextrin (CD), calixarene are commonly found hosts. As the secondary generation host, CD have received considerable attention because of its particular characterization, and the studies on host-guest interaction based on CD had been transferred from the processes and mechanism of inclusion complex between a pair of host and guest to construction of functional supramolecular aggregates, then these will be useful in the design and preparation of molecular machine and molecular devices, such as molecular pinchers, molecular gears, molecular motors and molecular balances, etc.In aqueous solution, CD can form stable inclusion complexes with less polar molecules (guests) that fit tightly inside the CD cavity. Among them, aromatics and their derivatives, adamantane and their derivatives and some metallocenes are commonly found guests. The stability of inclusion complexes between derivatives of ferrocene andβ-CD is correlated to the oxidation state of ferrocene and its derivates, and thereby the association or disassociation of the inclusion complex can be tuned by electrochemical approach, and these systems will have a very bright future in the design and preparation of intelligent fluids, smart supramolecular materials and supramolecular machines and devices.Based on this methodology, a water soluble bi-ferrocenyl guest,β-cyclodextrin labeled polyacrylamide andβ-cyclodextrin modified with amine were prepared in the present study, then the host-guest interaction between them has also been studied, and finally a supramolecular 3-dimensional networks and a physical hydrogel were obtained. The main contributions of this dissertation have been described in two sections.Frist, The quaternary ammonium salt of N, N'-bis(ferrocenylmethylene)diaminobutane andβ-cyclodextrin labeled polyacrylamide have been synthesized in this section. The composition and structures of the products have been determined and characterized by FTIR, ¹H NMR and elemental analysis. Furthermore, the host-guest interaction between the bi-guest molecule andβ-cyclodextrin labeled polyacrylamide has been systematically studied by employing. ¹H NMR, cyclovoltammetry, X-ray diffractometry, scanning electron microscopy techniques etc. As that expected, the two ferrocene groups attached to the ends of the linker can act as guest toβ-CD labeled on the backbone simultaneously, and form supermolecular 3-dimensional networks.Second, based on the host-guest interaction between the quaternary ammonium salt of N, N'-bis(ferrocenylmethylene)diaminobutane(FBI) and 6-deoxy-6-amino-β- cyclodextrin (β-CDNH₂), a supramolecular hydrogel was obtained, which is responsive to external stimuli like oxidation-reduction and pH etc. The morphography of the gel has been examined by using scanning electron microscopy, and the mechanism of gelation has been systematically studied by FTIR, ¹H NMR, cyclovoltammetry techniques, X-ray diffractometry, and UV-Vis spectroscopy. It has been demonstrated that formation of inclusion complexes and hydrogen bond betweenβ-CDNH₂ are the main driving forces for the gelation process. This finding must be useful for building up electric field responsive supramolecular materials.