The molecular conformation of cyclodi-β-alanyl
Abstract
Empirical force-field calculations have been used to predict the conformational preferences of the isolated (gas phase: 25°) molecule of cyclodi-β-alanyl. The twist-boat conformer with χi torsion angles of –28° is preferred to the extent of 1·4 kcal mol–1(steric energy) over the alternative twist-boat, with corresponding torsion angles of +35°, and to the extent of 2·1 kcal mol–1 relative to the centrosymmetric chair conformer.