“CLASSIC NMR” – A New In-Situ NMR Technique for Exploring the Evolution of Crystallization Processes

A new in-situ NMR technique, developed by the Harris group, has been published as a "hot paper" in Angewandte Chemie International Edition (DOI: 10.1002/anie.201404266). The new technique, which has been named "CLASSIC NMR" (Combined Liquid- And Solid-State In-situ Crystallization NMR), is the first NMR strategy that allows the time-evolution of both the liquid phase and the solid phase to be monitored simultaneously during crystallization processes. Previous applications of NMR techniques for in-situ studies of crystallization processes focused on the time-dependent changes in either the solid phase or the liquid phase, but the CLASSIC NMR strategy is unique in its ability to simultaneously probe both the solid and liquid phases as a function of time. Significantly, the new technique allows the time-evolution of the polymorphic form of the solid phase to be monitored while simultaneously providing insights on the corresponding time-dependent changes that occur in the modes of molecular aggregation and speciation in the liquid phase, as well as giving detailed insights on the kinetics of the crystallization process. It is anticipated that the advantages of the CLASSIC NMR strategy will yield significant new insights on a wide range of crystallization systems in the future.

The publication of the new technique was highlighted recently in the American Chemical Society's magazine C&E News.