Elucidation of polymorph mixtures using solid-state C-13 CP/MAS NMR spectroscopy and direct exponential curve resolution algorithm

Polymorphic behavior has a broad impact on chemical technology influencing the solid-state properties of many materials from pigments to pharmaceutica ls, The simultaneous presence of two or more polymorphs may introduce ambig uities in the characterization of materials using spectroscopy, diffraction , or scattering techniques. In this paper we present a solid-state C-13 NMR method, together with the recently published direct exponential curve reso lution algorithm, allows the elucidation of component spectra from the tota l spectrum of a mixture of polymorphs, previously characterized by X-ray di ffraction.