External electric field effect on photoinduced electron transfer from monomer and dimer of oxacarbocyanine in Langmuir-Blodgett films

Interlayer vectorial electron transfer from the excited state of oxacarbocyanine (OCC) to viologen (VIO) occurs in a molecular assembly composed of a mixed LB monolayer of OCC and a mixed LB monolayer of VIO separated by a spacer layer of a fatty acid. Fluorescence quantum yield of OCC in this system is changed by an external electric field, indicating that the photoinduced electron transfer rate is affected by an electric field. The rate is depressed or enhanced by an electric field, depending on the direction of the applied electric field. It was also found that monomer and dimer of OCC show different field effects on the electron transfer from each other in LB films.