The Photocatalytic Oxidation Of Dibenzothiophene And Its Derivatives By Iron Porphyrin

The SOx compounds released into the air from the burning of petroleum products do harm to the environment. With the increasingly strict environmental protection rules and norms, deep desulfurization of oil product is received tremendous attention from all over the world. DBTs as major sulfur containing compound in the oil, the containing of DBTs in the oil reveals the level of deep desulfurization. Therefore, DBTs is often researched as oil desulfurization template. In this artical, DBTs were catalyzed by iron porphyrin respectively for photocatalytic oxidation under the radiation of 250 W high-pressure mercury lamp. Then the influence of temperature, oxidant, catalyst and substrate to the reaction was studied.First, air was empioyed as oxidant, DBTO was empioyed as a substrate in the catalytic reaction, in which TCPPFeCl was used as a catalyst. It was found that biphenylene sultone (BPS) could be high selectively obtained as the major product in the reaction system, which is a product from the breakage of C-S bond in the starting material DBTO. And then, the influence of reaction temperature, solvent and substrate were discussed in this thesis. It was concluded that in aprotic solvent, under the optimal reaction condition, the target product BPS could be obtained less than 10% yield. Temperature had hardly effect on the reaction within a certain temperature range, while substituent group on 4,6 position of DBTO could cause obviously influence on the result. A typical case is that, when 4,6-DMDBTO was employed as the starting material, under the standard reaction condition, the yield of the corresponding BPS derivative was sharply reduced..Second, TBHP was empioyed as oxidant, DBT was empioyed as a substrate in the catalytic reaction, in which TCPPFeCl was used as a catalyst. Subsequently, the influence of reaction temperature, the type of catalysts, the amount of catalyst, the amount of oxidate and axial ligand were discussed in this thesis. It was found that iron porphyrin with electron-withdraw groups on the benzene ring showed higher selective toward the formation of BPS compared to the iron porphyrin with electron-ornor. When the reaction temperature was, 35 ℃, the dosage of catalyst was 0.044 eq, oxidant was 8 eq, under this reaction condition, the yield of desired BPS was 92.5%. The axial ligands as a additive of the reaction system could accelerate the decomposition of the catalyst, which resulted in the reduction of the reaction selectivity. Due to the steric hindrance, the presence of substituents on 4,6 position of DBT would decrease the selectivity.