Abstract The barriers to rotation about the C (O)[BOND] N bond for 13 α-alkyl-and α-halo- substituted N-theyl-N-methylamides were determined by 1 H NMR spectroscopy at coalescence temperature. Plots of Gibbs free energy (ΔG) and Gibbs energy of activation (ΔG‡) values against Charton's electronic and steric parameters of the α-carbonyl groups allows the conclusion that both the isomeric preference and the barrier to rotation about ...
