A Carbazole‐Centered Expanded Helicene Stabilized with Hexabenzocoronene (HBC) Units

Abstract

The synthesis and stabilization of heteroatom‐doped nanocarbon molecules, such as carbazole‐containing (super)helicenes, present significant challenges due to the complexities involved in maintaining structural integrity and electronic functionality. In this study, we successfully synthesized a carbazole‐centered expanded tris‐hexabenzo[7]helicene (1) via a facile FeCl3‐mediated Scholl coupling reaction. 1 exhibits both chemical and chiral stability and demonstrates fluorescence at 628 nm with a quantum yield of 0.40. Additionally, the enantiomers of 1 display pronounced chiroptical properties, including a distinct circular dichroism (CD) signal spanning from 300 to 600 nm. The absorption dissymmetry factor (|gabs|) is determined to be 2.98 × 10−3, while the circularly polarized luminescence brightness (BCPL) is measured as 32.50 M−1 cm−1.