PHOTOGENERATION OF HIGHLY ABSORBING TRANSIENT CHARGE STATES FROM MODEL DENDRITIC MACROMOLECULES BASED ON BIS-(DIPHENYLAMINO)DIPHENYLPOLYENE REPEAT UNITS

Bis-(diphenylamino)diphenylpolyenes form exceptionally stable, highly absorbing, bipolaronic charge states when oxidatively doped in solution, even at the stilbene level. These chromophores also display exceptionally large two-photon absorption cross-sections for ns laser pulses. 1,2-Bis-(diphenylamino)-E-stilbene moieties have now been incorporated into S-arm and four-arm dendrimer structures as formal repeat units. These new G-0 model dendrimers also form exceptionally stable, highly-absorbing bipolaronic charge states when oxidized in solution. As such these new materials are attractive candidates for various photonic applications which depend on the fast photogeneration of highly absorbing transient states. In the current study we have demonstrated that such states can indeed be photogenerated from the model dendrimers in solution in the presence of efficient electron accepters, such as C-60, In order to follow both the generation and decay of these excited state transient species, new spectroscopic techniques have been developed that have unique capabilities for examining transient state formation and subsequent dynamics.