Kinetic isotope effect of proton-coupled electron transfer in a hydrogen bonded phenol–pyrrolidinofullerene†
Proton-coupled electron transfer (PCET) plays a central role in photosynthesis and potentially in solar-to-fuel systems. We report a spectroscopy study on a phenol–pyrrolidinofullerene. Quenching of the singlet excited state from 1 ns to 250 ps is assigned to PCET. A H/D exchange study reveals a kinetic isotope effect (KIE) of 3.0, consistent with a concerted PCET mechanism.