Fullerene and π-Conjugated Oligomer Hybrids as Advanced Functional Materials

Two classes of π-conjugated oligomer linked bis-fullerene molecules with a triad motif of C60-π-C60 were synthesized and investigated. In the first series of C60-π-C60 hybrids, electron-rich OPE/OPV conjugated oligomers were employed to function as the central π-bridges and as the electron donors. Electrochemical and electronic absorption/emission spectral analyses indicate that the electronic interactions between the fullerene cage (acceptor) and the oligomer unit (donor) varied depending on the nature of the bridging unit. Complex excited state decay dynamics on the nanosecond timesccale were observed with time-resolved transient absorption spectroscopy. The second series of fullerene-oligomer hybrids use conjugated polyynes as the π-bridges. The unique structural rigidity and solid-state reactivity of the polyyne units impart these bis-fullerene molecular “dumbbells ” interesting interfacial aggregation behavior by forming spherical nanostructures on surfaces. This property could be useful for solid-state synthesis of fullerene based nanomaterials