13C-NMR SPECTRA OF N-BENZYLIDENEANILINES. EVIDENCE FOR DELOCALIZATION OF N-LONE-PAIR ELECTRONS TO ANILINE BENZENE RING

Abstract Several N-benzylideneanilines were synthesized which possess anilino benzene rings rotated out of the Ar–C=N plane by various degrees due to steric hindrance. Their 13C-NMR spectra indicated that the N lone pair electrons are delocalized to ring A especially in the compounds in which ring A is forced to rotate out of the molecular plane.