Synthesis, Crystallographic Characterization, and Proton-Modulated Physical Properties of an Azulene-Embedded Chiral Nanographene

The construction of novel nanographenes embedded with non-benzenoid rings offers a promising platform for advanced optoelectronic applications. Postfunctionalization of the tribenzo[a,d,g]coronene scaffold with an azulene unit remains largely undeveloped. Herein, we rationally synthesized novel chiral azulene-modified nanographene 6, whose structure was unambiguously confirmed by single-crystal X-ray diffraction. Compound 6 bearing a [6]helicene subunit was resolved via chiral high-performance liquid chromatography (HPLC), and its enantiomers displayed mirror-image CD spectra in dichloromethane regardless of the presence or absence of trifluoroacetic acid. These findings advance the design of tribenzo[a,d,g]coronene-derived nanographenes with tunable optoelectronic properties.