Multistep Electron Transfer in Oligopeptides: Direct Observation of Radical Cation Intermediates

Hopping holes: Oligopeptides with a photosensitive charge-injection system were synthesized and irradiated by a nanosecond laser. A multistep electron-transport process occurred which uses aromatic side chains as hole carriers (see scheme). The rates of this process indicate through-space electron transfer (a hopping mechanism).