Nanographene with a Nitrogen‐Doped Cavity

• Published in: Angewandte Chemie Vol. 136; no. 2
• Main Authors: Wang, Fei‐Fan, Wang, Yu‐Xiang, Wu, Qiong, Chai, Ling, Chen, Xuan‐Wen, Tan, Yuan‐Zhi
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 08.01.2024
• Subjects: Basicity; Cavities; Cavity; Chemical synthesis; Chemistry; Coordination; Electrochemistry; Graphene; Graphitization; Holes; Nanographene; Nitrogen; Nitrogen atoms; Photochemicals; Protonation; Protons; Pyridinic Nitrogen-Doping; Selective binding
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202315302

Nitrogen‐doped cavities are pervasive in graphenic materials, and represent key sites for catalytic and electrochemical activity. However, their structures are generally heterogeneous. In this study, we present the synthesis of a well‐defined molecular cutout of graphene featuring N‐doped cavity. The graphitization of a macrocyclic pyridinic precursor was achieved through photochemical cyclodehydrochlorination. In comparison to its counterpart with pyridinic nitrogen at the edges, the pyridinic nitrogen atoms in this nanographene cavity exhibit significantly reduced basicity and selective binding to Ag+ ion. Analysis of the protonation and coordination equilibria revealed that the tri‐N‐doped cavity binds three protons, but only one Ag+ ion. These distinct protonation and coordination behaviors clearly illustrate the space confinement effect imparted by the cavities. A nanographene with a tri‐N‐doped cavity was synthesized by photo‐induced cyclization. In comparison with nitrogen‐doping at the edge, this tri‐N‐doped holey nanographene exhibited markedly reduced basicity and selective affinity toward Ag+. This nanographene with a N‐doped cavity provides a precise model for understanding the binding in the nano‐confined defects of graphenic materials.