How to adjust the microstructure

macroproperties and function of prophyrins by tuning the substituents and central metal ions species has been the key and the challenge problem for designing the high activity and selectivity catalysts. It can provide important theoretical foundation for the accurate designing of metalloporphyrin catalysts to study the effects of the substituents and central metal ions on the electronic structure properties of porphyrins. In order to understand the relationship between microstructure and macro catalytic efficiency of porphyrins in essence

the electronic structures of metalloporphyrins with different substituents (—OCH3，—CH3，—H，—NO2) and different central metal ions (Mn，Fe，Co，Cu，Zn) were investigated using computational chemistry method based on density functional. The results indicated that the electron-withdrawing substituent (—NO2) lowered the levels of the highest occupied orbitals (HOMO) and lowest unoccupied orbital (LUMO) of metalloporphyrins. Whereas the electron-donating substitutes increased the levels of the HOMO and LUMO of metalloporphyrins. The central metal ions have an effect on the distribution of frontier molecular orbital. The frontier molecular orbitals of variant valence metalloporphyrins (Mn，Fe，Co) were mainly composed of 3 d orbital of metal ions

which facilitated the activation of dioxygen. The frontier molecular orbitals of invariant valence metalloporphyrins (Cu，Zn) were composed of large π bond from porphyrin ligands. The electrons could transport fluently in the large π bond

therefore the invariant valence metalloporphyrins also have the high activity. Fukui function suggested that the active sites of variant valence metalloporphyrins located on the central metal ions. Whereas the active sites of invariant valence metalloporphyrins might locate on the porphyrin ligands.