Recent advances in bioinspired proton-coupled electron transfer.

Mechanistic investigations of proton-coupled electron transfer (PCET) are increasingly important, especially in the context of small molecule activation and solar energy conversion. The main part of this invited Perspective discusses 16 mechanistic PCET studies published over the past 5 years that contributed significantly to understanding and controlling PCET in artificial systems. This includes bio-inspired work on tyrosine-Z mimics, reactions involving the transfer of multiple protons, de novo designed proteins with very long-lived tyrosyl radicals, and PCET in artificial DNA systems. Particular emphasis is on light-triggered reactions. An outlook into future directions for research on PCET is given at the end.