Molecular mechanics (MM3) calculations on aldehydes and ketones

Abstract

Aldehydes and ketones have been studied in some detail by using the MM3 molecular mechanics method. Approximately 50 structures have been calculated and compared with experimental data where available. Comparisons are also made of conformational equilibria, torsional potentials, moments of inertia, vibrational spectra, heats of formation, and other data. On the whole, the calculations yield information of experimental accuracy. The exception is in the case of vibrational spectra, where the rms error over four simple compounds amounts to 42 cm −1 . Heats of formation for 35 compounds are calculated to within 0.41 kcal/mol