| Summary: | 博士 === 國立臺北科技大學 === 工程科技研究所 === 97 === The dissertation comprises three subjects. In the first subject, we developed a water-soluble and air-stable catalytic system by synthesized the cationic bipyridyl ligand (containing two quaternary ammonium salts) to coordinate with the transition-metal (Pd, Fe). This cationic 2,2’-bipyridyl/palladium (II) or iron (III) catalytic system exhibits a recyclability and high activity for Suzuki-Miyaura reaction and the formation of carbon-sulfur bond in aqueous solution, respectively. After completing reaction, the residual aqueous phase after filtration or extraction could be reused for several cycles without a significant decrease in activity. This environmentally-friendly and cost-down catalytic protocol under green solvent condition and recyclable catalyst after simple manipulation can meet the goal of green chemistry.
In the second subject, we synthesized the novel heterogeneous catalyst which possesses a highly catalytic activity and recyclable property. The wormhole-like MCM-41 mesoporous silica (size 100 nm) is of high surface area (660 m2/g) and pore diameter (2.6 nm), which makes this material to be a useful support for a new generation of heterogeneous catalysis. The preparation of heterogeneous catalyst (NS-MCM-41-Pd) is to modify the bipyridyl palladium complex onto the NS-MCM-41 (nano-sized MCM-41) mesoporous materials. This NS-MCM-41-Pd proves to be an efficient heterogeneous catalyst to catalyze aryl bromides with organozinc reagents for Negishi reaction.
In the third suject, fluorescent surfactants with different conjugated aromatic moieties and changeable and gradually extended hydrophobic lengths were successfully synthesized by multiple synthesized manipulations. The novel cationic surfactants possess an extremely water-soluble ability ascribed to both di-cationic quaternary ammonium salts on the end of main framework. And other research is to discuss the photoluminescence (PL) behavior in aqueous solution when existence of variety of chromophores.
In the other hand, mesostructured nanocomposite with complete pore-filling of surfactants is an interesting research since such hybrid materials would provide greater control over the molecular alignment and stability. Hence we synthesized mesoporous materials prepared by using surfactant as organic template (comprised cationic quaternary ammonium salts and could extended hydrophobic segment up to 26 carbon-chains) and cheap sodium silicate as silica source (instead of TEOS). By adjusting condensation rate over molar ratio of silicate and surfactant, and the pH value of reaction mixture. The phase transition in different water content was recorded, which can find to optimum synthetic condition for physical properties (maximum pore size, surface area, well mesostructure and so on). In addition, hydrothermal treatment or not was also a key parameter of the resulting material.
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