During the last few decades, considerable efforts have been made toward the construction of donor–acceptor (D–A) linked systems that efficiently cause photoinduced charge separation, a fundamental step in natural photosynthesis and solar energy conversion. Among the building units for such D–A systems, nanocarbons deserve a special mention because it shows notable electronic conductivity, tenacious mechanical strength, and huge specific surface area. These singular properties place nanocarbon-based D–A systems in an attractive position as the next-generation material for energy-conversion devices such as solar fuels and organic photovoltaics. With this in mind, a variety of studies have been done to synthesize covalently linked systems of electron-accepting nanocarbons with electron-donating units such as pyrenes, porphyrins and phthalocyanines. However, the D–A interface frequently undergoes a rapid relaxation of the partially charge-separated (CS) exciplex or the completely CS state to the ground state, failing to generate a long-lived CS state that is crucial for solar energy conversion. In-depth understanding of the correlation between the structure and photodynamics of the electron donor-nanocarbon electron acceptor linked systems is important for extracting the full potential of such D–A materials for the potential applications.

In this talk I will show an overviw of our recent achievements related with photodynamics of pyrene- and porphyrin-attached chemically converted graphenes linked with oligophenylene bridge.

[1] T. Umeyama, J. Baek, Y. Sato, K. Suenaga, F. Abou-Chahine, N. V. Tkachenko, H. Lemmetyinen, and H. Imahori, Nat. Commun., 6, 7732 (2015).

[2] T. Umeyama, J. Baek, J. Mihara, N. V. Tkachenko, and H. Imahori, Chem. Commun., in press.

[3] T. Umeyama, T. Hanaoka, J. Baek, T. Higashino, F. Abou-Chahine, N. V. Tkachenko, and H. Imahori, J. Phys. Chem. C, in press.