2026-02-27 京都大学
＜関連情報＞
- https://www.t.kyoto-u.ac.jp/ja/research/topics/20260221
- https://www.t.kyoto-u.ac.jp/ja/research/topics/r80221seika_tanaka
- https://pubs.acs.org/doi/10.1021/jacs.5c20735
安定なNH含有キラルナノグラフェン：キラル光学およびスピン選択的輸送に向けた電子機能性窒素ドープπ共役系 A Stable, NH-Containing Chiral Nanographene: An Electroactive N-Doped π-System for Chiroptics and Spin-Selective Transport
Jorge Labella,W. Ryan Osterloh,Kean Kuo,Yusuke Tsutsui,Takayuki Tanaka,and Shu Seki
Journal of the American Chemical Society Published: February 26, 2026
DOI:https://doi.org/10.1021/jacs.5c20735
Abstract
The integration of nitrogen atoms into chiral nanographenes (c-NGs) offers a powerful strategy for designing chiral materials with programmable electronic and chiroptical responses. However, the preparation of stable N-doped c-NGs featuring free NH groups─an essential chemical handle─remains a major synthetic challenge. Herein, we report a highly stable N-doped c-NG (NHNG) featuring a free NH moiety, which enables comprehensive investigation of not only its structural but also its optical, redox, electronic, and spintronic properties. X-ray crystallography reveals an intriguing π-scaffold combining three coexisting topologies: two helical and one saddle-shaped. By virtue of its extended conjugation, NHNG displays strong visible-light absorption (ε = 170,000 M–1 cm–1) and a rich electrochemical profile, with four oxidations leading to persistent cationic species that exhibit sharp near-infrared absorptions. In parallel, time-resolved microwave conductivity measurements demonstrate notable photoconductivity (ϕΣμmax = 3.0 × 10–5 cm2 V–1 s–1). Owing to their robustness, the corresponding M– and P-enantiomers were resolved and found to exhibit pronounced chiroptical properties, with |gabs| = 4.2 × 10–3 and |glum| = 2.2 × 10–3. Remarkably, both enantiomers also display spin-selective charge transport via the chiral-induced spin selectivity effect, reaching spin-polarization values of ∼80%─among the highest reported for single-molecule-based π-conjugated spin filters. Altogether, these findings render NHNG a multifunctional chiral platform for next-generation optoelectronic, spintronic, and chiroptical applications.
