Internal rotation in some organic molecules containing methyl, amino, hydroxyl, and formyl groups

Abstract
Ab initio molecular orbital theory is used to study internal rotation in 20 organic molecules of the types X-Y, X-CH2-Y, X-SH-Y, X-O-Y, and X-CO-Y-where X and Y are methyl, amino, hydroxy, or formyl groups. In some of these molecules, internal rotation about two bonds is possible. The theoretical results are generally in moderate agreement with available experimental data and, in addition, lead to a number of predictions for molecules for which experimental information is lacking.