Bottom-up Molecular Synthesis of Atomically Precise Graphene Nanostructures and Their Emerging Properties

Graphene nanostructures are attracting attentions for their intriguing optical, electronic, and magnetic properties that are dependent on their precise chemical structures. Whereas defined structures are difficult to obtain by typical top-down fabrication methods, such as lithographic patterning of graphene, bottom-up chemical synthesis can achieve atomically precise molecular nanographenes and graphene nanoribbons (GNRs). Such graphene nanostructures can be synthesized on metal surfaces, using tailor-made molecular precursors, and directly visualized by scanning probe microscopy (SPM) and studied by various methods of Surface Science [1]. For example, we have synthesized a series of molecular nanographenes with zigzag edges, which demonstrated open-shell properties with singlet ground state and a large and structure-dependent magnetic exchange coupling of 100–190 meV [2,3]. While such magnetic nanographenes are typically unstable and studied under ultrahigh vacuum conditions, we have also explored solution synthesis of stable nanographenes that demonstrate strong red to near-infrared emission in solution states, e.g. toward super-resolution bioimaging [4]. Moreover, through the incorporation of helical substructures, nanographenes can be made chiral to demonstrate chiroptical responses [5]. In this talk, I will introduce our recent results on the bottom-up synthesize of such graphene nanostructures and their intriguing and varying structure-dependent properties.    

References

1. Z. Chen, A. Narita, K. Müllen, Adv. Mater. 32, 2001893 (2020).
2. S. Mishra, X. Yao, Q. Chen, K. Eimre, O. Gröning, R. Ortiz, M. D. Giovannantonio, J. C. Sancho-García, J. Fernández-Rossier, C. A. Pignedoli, K. Müllen, P. Ruffieux, A. Narita, R. Fasel, Nat. Chem. 13, 581 (2021).
3. K. Biswas, D. Soler, S. Mishra, Q. Chen, X. Yao, A. Sánchez-Grande, K. Eimre, P. Mutombo, C. Martín-Fuentes, K. Lauwaet, J. M. Gallego, P. Ruffieux, C. A. Pignedoli, K. Müllen, R. Miranda, J. I. Urgel, A. Narita, R. Fasel, P. Jelínek, D. Écija, J. Am. Chem. Soc. 145, 2968 (2023).
4. X. Zhu, Q. Chen, H. Zhao, Q. Yang, Goudappagouda, M. Gelléri, S. Ritz, D. Ng, K. Koynov, S. H. Parekh, V. K. Chetty, B. K. Thakur, C. Cremer, K. Landfester, K. Müllen, M. Terenzio, M. Bonn, A. Narita, X. Liu, Intrinsic Burst-Blinking Nanographenes for Super-Resolution Bioimaging. J. Am. Chem. Soc. ASAP (2024) DOI: 10.1021/jacs.3c11152.
5. X. Xu, R. Muñoz-Mármol, S. Vasylevskyi, A. Villa, G. Folpini, F. Scotognella, G. Maria Paternò, A. Narita, Angew. Chem. Int. Ed. 62, e202218350 (2023).