Establishing the Transitory Existence of Amorphous Phases in Crystallization Pathways by the CLASSIC NMR Technique1. Issue 24 (7th November 2018)

• Record Type: Journal Article
• Authors: Hughes, Colan E.; Williams, P. Andrew; Kariuki, Benson M.; Harris, Kenneth D. M.
• Is Part Of: Chemphyschem. Volume 19:Issue 24(2018)
• Page Start: 3341
• Page End: 3345
• Publication Date: 2018-11-07
• Subjects: amorphous phases -- crystallization -- in situ studies -- menthol -- solid-state NMR; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201800976
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: With the growing realization that crystallization processes may evolve through a sequence of different solid forms, including amorphous precursor phases, the development of suitable in‐situ experimental probes is essential for comprehensively mapping the time‐evolution of such processes. Here we demonstrate that the CLASSIC NMR (Combined Liquid‐ And Solid‐State In‐situ Crystallization NMR) strategy is a powerful technique for revealing the transitory existence of amorphous phases during crystallization processes, applying this technique to study crystallization ofdl ‐menthol andl ‐menthol from their molten liquid phases. The CLASSIC NMR results provide direct insights into the conditions (including the specific time period) under which the molten liquid phase, transitory amorphous phases and final crystalline phases exist during these crystallization processes. Abstract : Crystallization via amorphous intermediates : Application of the CLASSIC NMR technique for in situ studies of crystallization ofl ‐menthol anddl ‐menthol from their molten phases reveals direct spectroscopic evidence for the transient existence of amorphous phases prior to crystallization. The time evolution of the liquid, amorphous, and crystalline phases can be studied simultaneously in the same crystallization experiment.