C-13 NMR - SUBSTITUENT EFFECTS ON ONE-BOND N-15-C-13 COUPLING-CONSTANTS IN ANILINES AND ANILINIUM IONS

1J(15N13C) values obtained from FT 13C NMR spectra were measured for a number of 15N‐enriched aniline derivatives and are found to exhibit varying degrees of dependence on the nature of the ring substituent. Theoretical calculations of 1J(15N13C) values for representative members of the systems examined were made using INDO parameters and a ‘sum‐over‐states’ perturbation approach. The calculated coupling constants are generally in fair agreement with experimental values when the integral products SN2(o)SC2(o) and (r−3)N(r−3)C have values of 34.437 au−6 and 2.770 au−6, respectively. Copyright © 1979 Heyden & Son Ltd.