
%0 Journal Article
%A Fong, CW 
%A Grant, HG 
%T Torsional angles in N-substituted benzamides and related compounds by carbon-13 N.M.R. chemical shifts
%J Australian Journal of Chemistry
%D 1981/05/01
%V 34
%N 5
%P 957-967
%K 
%R https://doi.org/10.1071/CH9810957
%U https://www.publish.csiro.au/paper/CH9810957 
%X The torsional angles in 30 N-substituted benzamides and related compounds have been estimated by the use of the 13C substituent chemical shifts of the meta and para carbon atoms. Steric interaction between the N-substituted groups and the ortho hydrogen atoms of the benzene ring is the major determinant of non-planarity in these systems. A linear relationship between steric substituent constants of the N-substituted groups of some benzamides and the torsional angles is proposed. Dynamic processes involving rotation about the C-N bond, nitrogen inversion and ring inversion contribute a dynamic steric effect to the overall steric interaction. The preferred conformations of some N-substituted groups is also discussed. 
