A combination of a benzoxanthene cleft-type receptor with an electron-rich aromatic ring capable of establishing charge-tranfer interactions provides enantioselective receptors for dinitrobenzoylamino acids. Racemic mixtures of the receptor can be resolved with TLCs impregnated with the guest. The structure of the complexes has been established in an X-ray study. Enantiomeric amino acids provide complexes with different colors.
Copyright 2004 American Chemical Society