Synthesis, Crystal Analysis, and Physical Properties of Double [6]helicene-Containing Heteroarenes with Circularly Polarized Luminescence

Two novel helical heteronanographenes bearing a [6]­helicene unit (3a and 5a) have been synthesized, and their molecular structures are unambiguously determined via single-crystal X-ray diffraction analyses. Density functional theory calculations suggest that the as-prepared compounds have isomerization barriers of 29.02 kcal/mol for 3a and 34.07 kcal/mol for 5a, respectively. Optical enantiomers of 5a exhibit appealing chiroptical properties.