Research Interests

In the natural photosynthesis, the organic solar cells and the photocatalysis, transient radical species or carriers are immediately generated by the light-induced chemical reactions for the photo-energy conversion, providing essential sources of the living energies. However, we do not know how those transient molecules are initially interacting each other before the carrier-conductions take place. In our group, we are developing experimental methodologies to determine molecular positions, orbital orientations and orbital overlap (electronic coupling) in the initially generated radical-pairs or electron-hole pairs in the photoactive proteins, in the solar cells, and in the photocatalysis on the basis of the transient electron paramagnetic resonance (EPR) spectroscopies. Using these methods, we are clarifying several fundamental mechanisms of the energy-conversions in the photosynthesis and in the organic thin film solar cells.

Research Subjects

• Analysis of the geometries and electronic coupling in the primary charge-separated state in the photosystem II reaction centers of higher plants
• Mechanism of the initial charge-conduction and the electronic state at the interfaces in the photoactive layer in the organic photovoltaic systems
• Elucidations of the photoinduced proton-coupled electron transfer mechanisms in animal proteins for applications to the disease treatments

Selected Publications

◆"Regulated Electron Tunneling of Photoinduced Primary Charge-Separated State in the Photosystem II Reaction Center” M. Hasegawa, H. Nagashima, R. Minobe, T. Tachikawa, *H. Mino and *Y. Kobori, J. Phys. Chem. Lett. 8, 1179-1184 (2017).

◆"Self-Assembled Molecular Gear: A 4:1 Complex of Rh(III)Cl Tetraarylporphyrin and Tetra(p-pyridyl)cavitand” M. Nakamura, K. Kishimoto, *Y. Kobori, T. Abe, K. Yoza, *K. Kobayashi, J. Am. Chem. Soc. 138, 12564-12577 (2016).

◆"Geometries, Electronic Couplings, and Hole Dissociation Dynamics of Photoinduced Electron-Hole Pairs in Polyhexylthiophene-Fullerene Dyads Rigidly Linked by Oligophenylenes” T. Miura, R. Tao, S. Shibata, T. Umeyama, T. Tachikawa, *H. Imahori, *Y. Kobori, J. Am. Chem. Soc. 138, 5879-5885 (2016).

◆"Remarkable Dependence of the Final Charge Separation Efficiency on the Donor-Acceptor Interaction in Photoinduced Electron Transfer” T. Higashino, T. Yamada, M. Yamamoto, A. Furube, *N. V. Tkachenko, T. Miura, *Y. Kobori, R. Jono, *K. Yamashita, *H. Imahori, Angew. Chem. Int. Ed. 55, 629-633 (2016).

◆"Overcoming Coulombic Traps: Geometry and Electronic Characterizations of Light-Induced Separated Spins at the Bulk Heterojunction Interface” *Y. Kobori, T. Miura, J. Phys. Chem. Lett. 6, 113-123 (2015). (Perspective)