Pressure-induced pseudorotation in crystalline pyrrolidine†
Abstract
Pressure of 1.14(3) GPa leads to the crystallization of a new β phase of , but it is isostructural with monoclinic phase α, where all molecules are in the N-off envelope conformation. The energy associated with the pseudorotation constitutes only about 5% of the total energy change. The energetically unfavorable axial N–H position is retained.