MOTIONAL HETEROGENEITY AND POLYMORPHISM OF BISPHENOL-A DIACETATE

Two polymorphs of bisphenol-A diacetate 12,2-bis(p-acetoxyphenyl)propane] were characterized by solid-state C-13 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.