AbstractCalculations at the STO‐3G and 4–31G levels have been carried out on propylamine and ethylmethylamine, using geometries determined by molecular mechanics by allowing complete molecular relaxation in all degrees of freedom except for torsion about the central bond, and at 30° increments for the latter. It was found that a butanelike potential exists in each case. From 0° (cis) to 360° in order, the 4–31G values for the energy extrema are 5.92, 0.12, 3.88, 0.00, 3.94, and 0.51 kcal/mole for propylamine (with the nitrogen lone pairgaucheto carbon), and 7.06, 1.45, 3.44, 0.0, 2.87, and 1.44 kcal/mole for ethylmet