Two Different Lifetimes of Charge Separated States: a Porphyrin–Quinone System in Artificial Photosynthesis

Abstract

We investigated the charge separation process of an artificial photosynthesis molecule, zinc porphyrin–benzoquinone (ZnP–BQ) using the ab initio symmetry adapted cluster configuration interaction method and density functional theory. The energy of the charge separated (CS) state of the monomer indicates that electron transfer “via through bond” is inhibited. We used a dimer model of ZnP–BQ as an example for electron transfer “via through space” and qualitatively reproduced the experimentally determined energy relation. The calculated oscillator strengths show a difference in lifetimes between the CSLOW and CSHIGH states.