Application of NMR spectroscopy of chiral association complexes. 13—electron donor–acceptor complexes between racemic carbazolo[3,4‐c]carbazoles and an optically active acceptor

Strong electron donor–acceptor (EDA) association between carbazolo[3,4‐c]carbazoles and an optically active tetranitrofluorenone derivative was detected by UV–visible spectroscopy and by 1H NMR shifts. 1H NMR splittings at low temperatures are due to diastereomeric association complexes and, thus, prove the chirality of carbazolocarbazoles.