H-1 AND C-13 NMR-STUDIES OF PARASUBSTITUTED BENZALDOXIMES FOR EVALUATION OF THE ELECTRON-DONOR PROPERTIES OF SUBSTITUTED AMINO-GROUPS

H-1 and C-13 NMR spectra of seventeen (E)-benzaldoximes and three acet ophenone oximes, both carrying substituted p-amino groups, have been r ecorded and discussed from the point of view of substituent effect, Th e resonance effect of these substituents is not transmitted strongly t o CH=NOH group, However, it is found that the chemical shift of C-para depends linearly on sigma(R) degrees values. This dependence has been used to calculate the resonance substituent constants for the less co mmon amino groups and the 1-pyrrolidine group is found to be the most powerful electron donor among the substituents studied.