Synthesis of a magnetic π-extended carbon nanosolenoid with Riemann surfaces

• Published in: Nature communications Vol. 13; no. 1; pp. 1239 - 10
• Main Authors: Wang, Jinyi, Zhu, Yihan, Zhuang, Guilin, Wu, Yayu, Wang, Shengda, Huang, Pingsen, Sheng, Guan, Chen, Muqing, Yang, Shangfeng, Greber, Thomas, Du, Pingwu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.03.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 140/133; 147/143; 147/3; 639/638/298; 639/638/549; Carbon; Fabrication; Humanities and Social Sciences; Image resolution; Magnetic permeability; Magnetic properties; Magnetic susceptibility; Molecular structure; multidisciplinary; Paramagnetism; Phase contrast; Physical properties; Riemann surfaces; Scanning transmission electron microscopy; Science; Science (multidisciplinary); Synthesis; Topology; Transmission electron microscopy
• DOI: 10.1038/s41467-022-28870-z
• ISSN: 2041-1723

Riemann surfaces are deformed versions of the complex plane in mathematics. Locally they look like patches of the complex plane, but globally, the topology may deviate from a plane. Nanostructured graphitic carbon materials resembling a Riemann surface with helicoid topology are predicted to have interesting electronic and photonic properties. However, fabrication of such processable and large π-extended nanographene systems has remained a major challenge. Here, we report a bottom-up synthesis of a metal-free carbon nanosolenoid (CNS) material with a low optical bandgap of 1.97 eV. The synthesis procedure is rapid and possible on the gram scale. The helical molecular structure of CNS can be observed by direct low-dose high-resolution imaging, using integrated differential phase contrast scanning transmission electron microscopy. Magnetic susceptibility measurements show paramagnetism with a high spin density for CNS. Such a π-conjugated CNS allows for the detailed study of its physical properties and may form the base of the development of electronic and spintronic devices containing CNS species. Fabrication of large π-conjugated carbon nanosolenoid materials with helicoid topology remains a challenge. Here the authors demonstrate synthesis of a metal-free π-extended carbon nanosolenoid material with a helical structure, exhibiting unique photophysical and magnetic properties.