Dynamics of electronic energy transfer from the S2 state of azulene to the S2 state of zinc porphyrin

Electronic energy transfer between the S2 state of azulene as donor and the S2 state of zinc porphyrin as acceptor in dichloromethane and CTAB micelles has been investigated. In dichloromethane high S2–S2 energy transfer efficiency, which cannot be explained using the Förster theory, is observed. An inhomogeneous distribution of acceptors surrounding the donor, leading to short-range exchange interaction and higher multipole interaction is proposed. In CTAB micelles, Förster's mechanism is found to agree well with the observed energy transfer efficiency when a surface-uniform distance distribution between donor and acceptor is assumed. The implications of S2–S2 energy transfer in our system for designing efficient molecular devices is discussed.