Chiral induction in the CF 3 -and CH 3 -substituted phthalimide o-phenylenes was further studied by CD spectroscopy. As shown in Figure , all substituted chiral imides give significant CD bands in chloroform at 298 K, much more intense than were observed for the analogous H-substituted series. The CD peak intensities roughly correlate with the de's from the 1 H NMR experiments. The CD peak shapes are similar and match the spectrum calculated for oP , with characteristic Cotton effects at 250 and 280 nm. Overall twist senses were assigned from the spectra and are included in Table .