Heptagon-Embedded Helicene Derivatives: Synthesis, Crystal Structural Analyses, and Circularly Polarized Luminescence.

Two pairs of isomers of heptagon-embedded helical arenes ( 3 / 6 and 10 / 13 ) have been strategically prepared, where the molecular structures of 3 and 13 have been identified through single crystal X-ray diffraction analysis. The effect of the heptagon unit on the physical properties of 3 , 6 , 10 , and 13 is investigated in a comparative manner, and the results indicate that the optical enantiomers of 13 obtained from HPLC exhibit promising chiroptical properties.