A Nitrogen‐Doped Hexapole [7]Helicene versus Its All‐Carbon Analogue

Abstract

Abstract Two synthetic nanographenes (NGs), N‐H7H and C‐H7H , were prepared. N‐H7H is doped with nitrogen, and C‐H7H is the all‐carbon analogue. Both are hexapole [7]helicenes (H7Hs), and their structures were identified by single‐crystal X‐ray diffraction. Sharp contrasts in absorption ( abs λ max , 683 vs. 593 nm), emission ( em λ max , 894 vs. 777 nm), and electrochemical behavior ( ox E 1 , 0.28 vs. 0.53 V) were observed between N‐H7H and C‐H7H , and the origin of these differences was rationalized by theoretical calculations. Studies on N‐H7H and C‐H7H set a clear example to elucidate the remarkable effects of N‐doping on the physical properties of NGs.