Research Theme

Synthesis of Organic Electronic and Optoelectronic Materials

Keywords

Organic Synthesis, Graphene Molecule, Organic Semiconductor

Benzene is a hexagonal molecule that consists of six carbons and six hydrogens. Six electrons circulate around the carbon ring, which stabilizes the molecule. These π electrons are necessary for organic materials to show photonic, electronic, and magnetic properties. Benzene derivatives with some hexagons are called aromatic compounds. We would like to synthesize unique aromatic molecules such as C60 fullerene. C60 resembles a soccer ball with twenty hexagons and twelve pentagons. It was extracted from carbon soot and isolated in 1990. Researchers found that C60 works as superconductors, ferromagnets, and n-type semiconductors. These outstanding properties come from its unusual structure.

To make such unique organic materials, one should design molecules with extraordinary structures. We have synthesized [8]circulene that has an octagon surrounded by hexagons^1）. Its saddle shape looks like a potato chip. [8]circulene works as a p-type semiconductor. We also produced some carbon nanorings that contain four carbazole molecules^2）. Recently, we reported fully fluorinated rubrene molecule as an n-type semiconductor ^3）.

Molecular structures of C60, [8]circulene, carbazole nanoring, and perfluororubrene.

Selected Publications

1. Y. Sakamoto and T. Suzuki, “Tetrabenzo[8]circulene: Aromatic Saddles from Negatively Curved Graphene,” J. Am. Chem. Soc. 135, 14074–14077 (2013).
2. Y. Kuroda, Y. Sakamoto, T. Suzuki, E. Kayahara and S. Yamago, “Tetracyclo(2,7-carbazole)s: Diatropicity and Paratropicity of Inner Regions of Nanohoops,” J. Org. Chem. 81, 3356-3363 (2016).
3. Y. Sakamoto, T. Suzuki, “Perfluorinated and Half-Fluorinated Rubrenes: Synthesis and Crystal Packing Arrangements,” J. Org. Chem. 82, 8111-8116 (2017).