Study On Catalyzed Oxidation Mechanism Of Iron Porphyrin-like Compounds

Iron porphyrin-like compounds are very important in life system. They play a crucial role in the storage and transport of electrons and oxygen. For instance, hemoglobin transport 02, myoglobin storage 02 and Cytochromes P-450 catalyze substrates hydroxylation. Now many studies have been performed on catalysis mechanism of iron porphyrin by using various experimental and theoretical methods. The catalytic capabilities of iron porphyrin lie in its redox property and coordination between metal and axial ligands. Redox property is based on conjugate ir -electron system and changing of the valence of metal atom. Changing the constituents and structure of iron porphyrin, such as metal center atom, substituents on the porphyrin ring and axial ligands, will alter catalytic activities of iron porphyrin. In this dissertation, we studied the catalysis mechanism of iron porphyrin catalyst and established the quantitative structure-catalytic activity relationship. According to the mechanism of iron porphyrin catalytic cycle and influence factors of catalytic reaction, nine iron porphyrins which have different substituents on the porphyrin ring and six iron porphyrins which have different axial ligands were chosen as samples to calculate. In catalytic reaction, each iron porphyrin has six reaction intermediates and each intermediate has three spin states. So it total 270 types of structure. Five factors were chosen as main influence factors: heat of formation, net charge of metal center atom, HOMO and LUMO. Statistical analyses indicate that energy of the frontier orbitals is the main influence factor. Calculations were finished on the PIll 800 microcomputer, using HyperChem5.1 software and semiempirical 桵P3(tm) method. Data processing use Statistica professional statistical software.