Double [8]Helicene Featuring a Dibenzo[g,p]chrysene Core: Synthesis and Chiroptical Response

Double [8]helicene 1, featuring a dibenzo[g,p]chrysene core, was synthesized via the Scholl reaction, and its structure was unambiguously confirmed by single-crystal X-ray diffraction analysis of its dicationic salt [1-Cl]2+·(SbCl6-)2. The compound exhibits red fluorescence with an emission maximum at 618 nm (λem) and a quantum yield of 16.2%, highlighting its potential in optoelectronic applications. Furthermore, circular dichroism (CD) and circularly polarized luminescence (CPL) measurements reveal notable chiroptical activity, with absorption and emission dissymmetry factors of |gabs| = 5.11 × 10-3 and |glum| = 7.1 × 10-4, respectively.