A First Principles Study on Zinc–Porphyrin Interaction with O₂in Zinc–Porphyrin(Oxygen) Complex

Abstract

We investigate the interaction between zinc–porphyrin and oxygen molecule in zinc–porphy-rin(oxygen) complex using the first principles calculation. At first, we study the electronic and geometric structures of zinc–porphyrin and compare with other metalloporphyrin (metal = Mn, Fe, Co, and Ni). We demonstrate that the electronic structures of zinc–porphyrin are completely different with other metalloporphyrin, therefore its interaction with oxygen molecule is also different. In the ground state, the complex prefers the form 3 ( 1 ZnP– 3 O 2 ). The singlet oxygen generation can be accessed through 1 (ZnP–O 2 ) complex. The excited singlet state of the complex prefers the form 1 ( 1 ZnP– 1 O 2 ) and allows the interaction between ZnP and O 2 via charge transfer. Furthermore, we construct a mechanism for the quenching of 3 ZnP induced by 3 O 2 where ZnP–O 2 complexes act as the intermediate states.