Zhu Xujie, Jiang Yashi, Wang Zhou, Huang Yicheng, Luo Zhengqiang, Yan KaKing, Wang Shiyong, Yu Ping
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
J Am Chem Soc. 2025 Mar 26;147(12):10045-10051. doi: 10.1021/jacs.4c13998. Epub 2025 Mar 18.
Polyradicals obtained from open-shell coronoids hold promise for applications in spintronics and quantum technologies due to the strong interactions between spins in fully fused cyclic systems. Coronoid synthesis has long been considered difficult due to the cyclization of nanographene. It becomes an immense challenge to synthesize open-shell coronoids since radicals appear only when the macrocycle size exceeds a critical value. Here we present an open-shell coronoid with six radicals achieved through an on-surface synthesis. This spin coronoid displays a collective spin state arising from both the nearest-neighbor exchange interaction and the next-nearest-neighbor exchange interaction of six unpaired π electrons along the conjugation pathways. The characterization of the spin excitation from the ground state to the excited state was carried out by using inelastic electron tunneling spectroscopy. Additionally, we show that the spin coronoid can be utilized as a nanoscale platform to achieve short antiferromagnetic spin-1/2 Heisenberg chains through tip manipulation. Our findings present a design strategy for creating coronoids with polyradicals, which could provide inspiration for fabrication of open-shell coronoid or cyclic spintronic systems.
由于完全融合的环状系统中自旋之间的强相互作用，从开壳冠状化合物中获得的多自由基在自旋电子学和量子技术中具有应用前景。由于纳米石墨烯的环化，冠状化合物的合成长期以来一直被认为很困难。合成开壳冠状化合物成为一项巨大的挑战，因为只有当大环尺寸超过临界值时才会出现自由基。在此，我们展示了一种通过表面合成实现的具有六个自由基的开壳冠状化合物。这种自旋冠状化合物表现出一种集体自旋态，它源自沿着共轭路径的六个未配对π电子的最近邻交换相互作用和次近邻交换相互作用。通过使用非弹性电子隧穿光谱对从基态到激发态的自旋激发进行了表征。此外，我们表明自旋冠状化合物可以用作纳米级平台，通过针尖操纵实现短的反铁磁自旋 - 1/2海森堡链。我们的研究结果提出了一种创建具有多自由基冠状化合物的设计策略，这可能为开壳冠状化合物或环状自旋电子系统的制造提供灵感。
