Author(s): Hassan B. Amin
Article publication date: 1994-04-01
Vol. 12 No. 1 (yearly), pp. 9-27.
190
Keywords
chemical shifts, spectroscopy, carbon-12
Abstract
1H- and 13C-NMR chemical shifts are reported for a series of 18 imines, Ar(OH) (Br) CH=N-R , and 18 amines, Ar (OH) (Br) CH 2NH-R (R=CH], 'Pr, 'Bu , sBu, 'Bu or Ph), The amines were obtained by the reduction of the appropriate imine . The stereochemistry of imines was determined through their NMR spectral data. The imines were found to exist in solution as only a single E-isomer at ambient temperature, Interestingly , the carbon-13 chemical shifts for imino (CH=N) and benzylic (PhCH2) carbons are affected by alkyl groups (R), while the halo-substituted benzene ring has no effect on the chemical shift of the imine group , Substituent chemical shift (SCS) effects for - OH, - Br, CH = N-, CH2-NH , or - CHO are not additive at all positions,