Theoretical Study Of The Reaction System In Organic Transition Metal Compounds

Based on density functional theory(DFT) and B3LYP method, we made a theoretical study of the reaction system involving organic transitional metal compound and the (Salen)Mn(V)-catalyzed epoxidation. We studied the mechanism of each reaction. We determined the structure of the reactants, intermediates, products and transition states,and discussed the change of the structures in all the reactions.Chapter one mainly deals with a series a-hydrogen shift reactions between the alkylidene and alkylidyne organometallic molybdenum complexes R₃R₄Mo(≡CH)(CHR₁R₂) and R₃R₄Mo(=CH₂)(=CR₁R₂). The purpose is to find out the most preferable substitutes that can lower the active energy to a largest extent. At the same time, we changed the central transitional metal to study its effects on active energy.In the second chapter, we studied enantioselectivity in the (Salen)Mn(V)-catalyzed asymmetric epoxidation reaction. The results of a series of model systems of different spin states are presented. The caculated results show that the triplet state play a major role. At the same time, there are hydrogen bond interactions of the NMO with the (Salen)Mn(V) complex, or olefin, which make the enantioselectivity higher than that without the NMO.