Changing the game of time resolved X-ray diffraction on the mechanochemistry playground by downsizing

Time resolved in situ (TRIS) monitoring has revolutionised the study of mechanochemical transformations but has been limited by available data quality. Here we report how a combination of miniaturised grinding jars together with innovations in X-ray powder diffraction data collection and state-of-the-art analysis strategies transform the power of TRIS synchrotron mechanochemical experiments. Accurate phase compositions, comparable to those obtained by ex situ measurements, can be obtained with small sample loadings. Moreover, microstructural parameters (crystal size and microstrain) can be also determined with high confidence. This strategy applies to all chemistries, is readily implemented, and yields high-quality diffraction data even using a low energy synchrotron source. This offers a direct avenue towards the mechanochemical investigation of reactions comprising scarce, expensive, or toxic compounds. Our strategy is applied to model systems, including inorganic, metal-organic, and organic mechanosyntheses, resolves previously misinterpreted mechanisms in mechanochemical syntheses, and promises broad, new directions for mechanochemical research.
Time-resolved in situ (TRIS) X-ray powder diffraction promises great potential to study mechanochemical processes. Here, the authors develop a strategy to enhance the resolution of TRIS experiments to allow deeper interpretation of mechanochemical transformations; the method is applied to a variety of model systems including inorganic, metal-organic, and organic mechanosyntheses.