Photogeneration of 2-Deoxyribonolactone in Benzophenone−Purine Dyads. Formation of Ketyl−C1′ Biradicals

Photolysis of the title dyads under aerobic conditions leads to a 2-deoxyribonolactone derivative. Laser flash photolysis reveals that the process occurs from the short-lived benzophenone-like triplet excited state. A mechanism involving intramolecular electron transfer with the purine bases (adenine, guanine, or 8-oxoadenine) as donors is proposed.