Direct observation of a transient polymorph during crystallization

Application of a technique developed for in situ solid-state 13 C NMR studies of crystallization processes reveals direct evidence that crystallization of glycine from a methanol/water solution involves the initial transient formation of the β polymorph, which then undergoes a solution-mediated polymorphic transformation to yield the more stable α polymorph. In situ solid-state 13 C NMR studies yield direct evidence that crystallization of glycine from methanol/water involves the initial transient formation of the β polymorph.