Preparation And Catalytic Aerobic Oxidation Activities Of Polymeric Crown Ether-Salen Schiff Base Metal Complexes

In order to catalyze oxidation of hydrocarbon compound with molecular oxygen in an environment friendly process, the structures and catalytic activity of cytochrome C and cytochrome P-450 have been studied. Synthetic porphyrin and quasi-porphyrin metal complexes were also studied for mimic of above natural polymer metal complexes catalysts with many kinds of methods. Based on research of polymer metalloporphyrin catalytic system,polymeric quasi-potphyrin metal complexes of our group, in this thesis, we try to synthesize a new type of polymeric quasi-porphyrin-Crown ether metal complexes, and study their catalytic oxidation properties for mimic the function of cytochrome of catalytic activity.Firstly, synthesis and catalytic performances of different Salen Schiff base metal complexes were reviewed. The synthesis and effective catalytic activity of the quasi-porphyrin-Crown ether metal complexes was also reviewed. It suggested that Crown ether ring is an oxygen affinity group, especially six oxygen atom arrange ruly in Crown ether ring. Therefore, the molecular oxygen is easy to enter the complex center, and form stable dioxygen adduct complex, and show effective activation of molecular oxygen.Secondly, a new kind of Crown ether-Salen Schiff base heterobinuclear polymeric metal complexes SalCo-3NaCrown and SalMn-2NaCrown was prepared by condensation reaction. The ligand and its complexes were characterized by the FT-IR, SEM, Elemental analysis, TG-DTA and XPS. It's catalytic activity in oxidation of cyclohexene with molecular oxygen at atmosphere pressure showed that the catalyst have high activity (turnover number: 2.7×10⁵), high selectivity (72%) and reusability. The reaction mainly took place on the allyl carbon of the cyclohexene, which afforded corresponding 2-cyclohexene-ol (-OH) and 2-cyclohexene-one (C=O). The Crown ether sodium - Salen Schiff base Co²⁺ and Mn²⁺ metal complexes were used as catalysts for the aerobic oxidation of 1-octene, 1-decene and a-methylstyrene. It showed the good catalytic activity. They were also used for catalytic oxidation of cumene with molecular oxygen without reductant, which afforded corresponding 2-phenyl-2-propanol (PP) and cumene hydroperoxide (CHP).Thirdly, the Salen Schiff base-Crown ether copper complex (SalCul5C5-Cul8C6) was prepared by condensation reaction, and characterized by the FT-IR, SEM, TG-DTA and XPS. The SalCul5C5-Cul8C6 showed good catalytic activity in oxidation of cumene with molecular oxygen at atmosphere pressure, which afforded 2-phenyl-2-propanol (PP) and cumene hydroperoxide (CHP). The selectivity of (PP) is 68%. The turnover number arrived to 17.4×10⁵. The effective factors in the oxidation of cumene catalyzed by the polymeric Schiff basse-Crown ether metal complex were discussed. The mechanism is also discussed.Finally, the copolymer metal complexes, SalCo-NaB18C6, was prepared by chain-growth polymerization. It was characterized by the FT-IR, SEM, TG-DTA and XPS. This copolymer metal complex was applied to catalytic oxidation cyclohexene of molecular oxygen without reductant. It was found that the reaction mainly took place on the allyl carbon of the cyclohexene, which afforded corresponding 2-cyclohexene-ol (-OH) and 2-cyclohexene-one (C=O). The selectivity of (C=O) is 89%. The conversion arrived to 89%. The Crown ether - Salen Schiff base metal complexes were used as catalysts for the oxidation of a-methylstyrene (the total selectivity is 81%; conversion is 60%), 1-decene and ( the selectivity is 65%; conversion is 40%) and 1-octene by oxygen showed the good catalytic activity.