Photooxidation of organic matter via the excited-state Proton-Coupled Electron Transfer (PCET) reaction, involving the transfer of both a proton and an electron, is a fundamental process that occurs in natural and engineered environments. PCET plays a crucial role in various environmental, biological, and technological systems. Understanding the mechanisms and dynamics of this reaction is of great significance for advancing renewable energy technologies and developing sustainable methods for fuel production. Investigation of the intermolecular PCET process in hydrogen-bonded complexes is widely used in theoretical modeling of hydrogen-evolution photocatalysis (for recent reviews, see ).