Relevance of Electron‐Driven Proton‐Transfer Processes for the Photostability of Proteins

Ultrafast coupled electron–proton transfer: The locally excited (LE) electronic state is deactivated via two sequential electron-transfer (ET) processes at conical intersections of the LE state (blue) and the electronic ground state (black) with a charge-transfer state (red). After each electron transfer, the proton follows the electron, thus accepting the energy deposited by the UV photon in the molecular system.