Photoinduced electron transfer in metalloporphyrins

As a macromolecular heterocyclic compound, metalloporphyrin has proven to be very important for energy, environment, catalysis, and especially biological processes and biomedical applications. Herein, we synthesized a series of butterfly-shaped and distorted tetrahedral geometry tetracobalt complexes with different monophosphine ligands and coordinated them to zinc meso‑tetraphenylporphyrin (ZnTPP). The supra-molecular systems have been studied by fluorescence spectra, electrochemistry, and density functional theory (DFT), confirming that the electron transfer from the photo-excited ZnTPP to cobalt atoms relied on the zinc-nitrogen coordination bond, thereby quenching the fluorescence intensity from 4495.3 to 266.0 (Stern-Volmer constant). These characteristics have important potential in inhibiting photodynamic therapy (PDT) side effects and can be further researched and developed for photonics, imaging, acoustics, photocatalysis, and related biomedicine, energy, and environment applications.