Motional heterogeneity and polymorphism of bisphenol‐A diacetate

Two polymorphs of bisphenol‐A diacetate [2,2‐bis(p‐acetoxyphenyl)propane] were characterized by solid‐state 13C cross‐polarization magic‐angle spinning NMR, X‐ray powder diffraction and differential scanning calorimetic measurements. The structure of one polymorph was determined by single‐crystal x‐ray diffraction methods, and shown to have two molecules in the asymmetric unit. The two polymorphs show markedly different molecular mobilities, as reflected in variable‐temperature solid‐state NMR measurements, with one polymorph exhibiting motional heterogeneity in the flipping of the phenylene rings.