Circular dichroism of some optically active 2,3-dichloromaleimides

Optically active derivatives of 2,3-dichloromaleimide give bisignate excito n-coupled type Cotton effects in circular dichroism spectra which can be co rrelated with the absolute configuration of chiral non-racemic aryl amines, aryl a-amino acids, and amino alcohols. The presented data indicate that t hese experimentally observed Cotton effects originate from the pi --> pi* e lectronic transition of the maleimide chromophore and that this transition is polarized perpendicularly to the symmetry axis of the maleimide chromoph ore.