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

Electronic energy transfer between the S-2 state of azulene as donor and the S-2 state of zinc porphyrin as acceptor in dichloromethane and CTAB micelles has been investigated. In dichloromethane high S-2-S-2 energy transfer efficiency, which cannot be explained using the Forster 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, Forster'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 S-2-S-2 energy transfer in our system for designing efficient molecular devices is discussed.