Synthesis And Study On Catalytic Properties Of Molybdenum Complex Catalyst Based On Dendritic Polyamide

The epoxidation reaction is one of the important organic reactions, the epoxidation product is a very versatile intermediate in organic synthesis. Cyclohexene oxide, a high value-added industrial production, is the biggest industrial trading epoxy compound. Cyclohexene, the ideal raw material for cyclohexene oxide, is cheap and easy available, moreover in line with the concept of atom economy. But, cyclohexene epoxidation reaction is relatively complex and produces by-products. Therefore, there is an urgent need to find a suitable catalytic reaction for cyclohexene epoxidation reaction, resulting in higher industrial value. This paper intends to synthesize dendrons polyamide loaded molybdenum alloy a quinolinol catalyst to solve the problems about the conventional transition metal catalyst which is poor selectivity and hard to be separated from the reaction system, non-renewable and non-reused.A series of8-Hydroxyquinoline Molybdenum (Ⅵ) compexes were synthesized and their catalytic behaviors were investigated in epoxidation of cyclohexene with tert-butyl hydroperoxide in chlorobenzene medium. The structures and properties of the catalysts were studied via FT-IR, TG and elemental analysis. The results show that substituent groups had large influences on the catalytic activity. The enhanced effect of the catalytic activity can be more obvious along with the improvement of the substituent groups’electron-releasing ability. The stability and activity of the catalyst become higher as the atomic number grow. A series of comparative experiments were studied to determine the optimal parameter combination. The results show the best optimal reaction conditions is:feeding ratio3:1, the quantity of oxidant TBHP0.04mol, the amount of catalyst0.3mmol, chlorobenzene solvent amount of10ml, the reaction temperature is353K, the reaction time is60min.The dendrons polyamide catalyst with the periphery chloromethyl groups, loaded molybdenum (Ⅵ) and8-quinolinol. The dendrons polyamide catalyst were investigated by IR, NMR, XRD, TG and TEM and its catalytic properties were also studied. The results showed the branches polyamide loaded molybdenum (Ⅵ)8-hydroxyquinoline catalyst presented amorphous state and the pore structure, moreover the higher generation of dendrons polyamide corresponding to the more obvious pore structure; The content of molybdenum loaded in the dendrons polyamide are more than theoretical graft quantity, part of molybdenum exists in the form of lattice; With the optimized catalytic reaction system, Catalytic activity is increased to97%, and it’s selectivity increased to99%. The catalytic didn’t appear obviously decline in activity and selectivity when recycling reused five times.