Development of Functional Materials Based on Efficient Synthesis of PAHs Containing Pentagonal Rings

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04111
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Organic chemistry
• Research Institution: Osaka Institute of Technology
• Principal Investigator: Murata Michihisa 大阪工業大学, 工学部, 准教授 (30447932)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 多環芳香族炭化水素 / 固体発光 / 芳香族性 / カーボン物質 / 単結晶X線構造解析 / 酸化的クロスカップリング

Outline of Final Research Achievements

Polycyclic aromatic hydrocarbons (PAHs) that contain fully unsaturated pentagonal ring(s), the so-called CP-PAHs, have attracted substantial interest due to their unusual properties such as high electron affinity and reactivity. In this project, we demonstrated the facile synthesis of a dithieno-fused CP-PAH that contains a pyracylene moiety from a twofold Scholl cyclization. The results of a combined experimental and theoretical approach revealed a strong contribution of antiaromatic character to the electronic structure of this dithieno-fused CP-PAH. Furthermore, we found the twofold Scholl cyclization of a 5,11-dinaphthyltetracene derivative, which affords a twisted PAH that contains fully unsaturated pentagonal and hexagonal rings. This reaction should proceed via dication intermediates, which stands in stark contrast to the previously reported mechanisms that involve radical cation or arenium ion intermediates.

Free Research Field

有機化学

Academic Significance and Societal Importance of the Research Achievements

本研究では，電子受容性の多環芳香族化合物に関して，実験および計算化学の両アプローチから検討を実施し，酸化的C-Hカップリング反応を用いる手法により5員環構造を含む一連のCP-PAH類を効率的に合成できることを実証した。また，長くPAH類の合成に多用されてきた酸化的C-H カップリング反応が，テトラセン誘導体の二重環化反応においては，これまで提唱されていないジカチオン中間体を経る反応機構で進行することを初めて示した。