Circular dichroism of some optically active 2,3-dichloromaleimides

Optically active derivatives of 2,3-dichloromaleimide give bisignate exciton-coupled type Cotton effects in circular dichroism spectra which can be correlated with the absolute configuration of chiral non-racemic aryl amines, aryl alpha-amino acids, and amino alcohols. The presented data indicate that these experimentally observed Cotton effects originate from the pi-->pi* electronic transition of the maleimide chromophore and that this transition is polarized perpendicularly to the symmetry axis of the maleimide chromophore.