Adiabatic electron-transfer is a type of oxidation-reduction processes.  The mechanism is ubiquitous in nature in both the inorganic and biological spheres. Adiabatic electron-transfers proceed without making or breaking chemical bonds.  Adiabatic electron-transfer can occur by either optical or thermal mechanisms.  Electron transfer during a collision between an oxidant and a reductant occurs adiabatically on a continuous potential-energy surface.