| Nowadays, a lot of toxic, volatile organic solvents are used in chemical industries which can't comply with the concept of green chemistry. Therefore, ionic liquids have received much attention as greener alternative to organic solvents. Ionic liquids are made of organic cations and inorganic or organic anions which can be used as electrolytes at room temperature. They have many advantages such as high thermal stability, no measurable vapor pressure, wide liquid range, adjustive for better solubility, good catalytic property which lead to the quick development of the ionic liquids.This thesis was mainly about the synthesis, characterization and catalytic property of the functional ionic liquids. It was composed with three sections. The first section was about Knoevenagel condensation catalyzed by basic ionic liquid in water. The second section was about oxidative desulfurization catalyzed by Bronsted acid ionic liquid. The third section was about the synthesis of novel ionic liquids in which the anions were asymmetric.In the first section, an efficient, environmentally friendly procedure was developed for the condensation of aldehydes / ketones and activated methylene compounds using a basic ionic liquid as a catalyst in water. The basic ionic liquid catalyst displayed very high activity for Knoevenagel condensation to give the corresponding products in 70-97 % isolated yields under mild conditions at 30℃. Different organic solvents were also used as solvents for comparison. Water gives the highest activity. The basic ionic liquid can be reused for 6 times without significant loss of activity.In the second section, Bronsted acid ionic liquid [HMIm]BF4 was used as a catalyst and solvent for desulfurization. The sulfur removal of the model oil such as dibenzothiophene, benzothiophene, thiophene, sulfides and so on (the sulfur content was 1000 g/mL) can reach 50-93% under the different reaction temperatures, which was much more superior to the simple extraction with ionic liquids. The sulfur removals were decreasing in the order of dibenzothiophene > benzothiophene > thiophene. The ionic liquid [HMIm]BF4 can be recycled for 6 times without a significant decrease in activity. In the third section, 22 novel ionic liquids were synthesized by ion-exchanging several kinds of cations with the asymmetric anions [C(CN)2(COCH3)]-, [C(CN)2(SO2CH3)]- and [C(CN)2(COC7H15)]-. The ionic liquids were characterized by NMR, IR, LC-MS. Their thermal stability, electrochemical windows and melting points were also measured. Their thermal decomposition temperatures were between 291 °C -324℃. The electrochemical window of ionic liquid [BMIm] [C(CN)2(COCH3)] was 3.6V. The results showed that the ionic liquids had wide electrochemical windows and excellent thermal stability. The melting points of ionic liquids were related to the asymmetry of the anions and the distribution of electric charge.
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