Studies On Functional Host-guest Assembly Systems Based On Layered Materials

When a guest species is encapsulated in a host, composite host-guestcompounds with unusual properties may form. Layered inorganic materialshave been extensively consider as a good host to incorporate functional guestspecies which yield a variety of useful applications as catalyst, ion conductors,shape-selective adsorbents, ion exchangers, photofunctional materials, etc.,and many novel assembly structures can be tailored at the molecular levelthrough the design of the host and the guest species. In this thesis, we describesome new host-guest systems related to layered materials.1. Intercalation of DNA-Ethidium Complex into Layered DoubleHydroxide. A new composite compound LDH-DNA-ET has been preparedthrough intercalation of ethidium and DNA molecule into the layers of layereddouble hydroxide (LDH). The LDH-DNA-ET compound has beeninvestigated by various analytical methods such as X-ray diffraction, infrared,UV-vis and circular dichroism spectroscopy, element and thermogravimetricanalyses. The interlayer distance of the LDH-DNA-ET compound is 4.6 nm,larger than that of the pristine LDH. Taking into account the structure of theDNA molecule and the ET molecule, it is proposed that there are two layers ofDNA-ET composite between two adjacent LDH sheets. The DNA moleculesin the LDH-DNA-ET compound retain their chemical and biological integrity.The LDH-DNA-ET compound gave rise to photoluminescence of λem,max=610 nm under the excitation of a laser light of λex=488 nm.LDH-DNA-ET compound has potential significance about functionalmaterials of DNA development.2. Lysine and Cetyltrimethyl Ammonium Bromide(CTAB) Co-intercalatedMontmorillonite and Study on Its Catalytic Action. We succeeded toIntercalate lysine (Lys) molecules and CTAB molecules into between thelayers of montmorillonite at room temperature through an ions-exchangetechnique,and the production is MLC. Powder X-ray diffraction and infraredspectrum analysis indicate that the lysine molecules and the CTAB moleculesare intercalated into between the inorganic layers. The MLC molecules isstabilized in water and the lysine molecules and CTAB molecules can notescape from the layer. The MLC composite in combination with benzaldehydeand chloroform has also been applied in the reaction as a catalyst. However,the regathered MLC molecules showed high catalytic activity for the reaction.So, the catalyst's repetition is not impossible.