Femtochemistry uncovers the nature of electron transfer reactions.

Beyond searching for an understanding of the molecular details involved in acid–base and related charge-transfer reactions is the large field of biochemistry, for which numerous charge-transfer questions arise, including those related to charge migration in DNA (9–11), processes in photosynthetic reaction centers (12), and other protein systems (13, 14). Photoinduced electron transfer plays a major role in triggering numerous chemical and biological processes, and there is …