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

Abstract

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.

Multi-faceted reactivity of N-fluorobenzenesulfonimide (NFSI) under mechanochemical conditions: fluorination, fluorodemethylation, sulfonylation, and amidation reactions

“…From a sustainable point of view, experimenting in small scale could prevent waste production and increase safety. However, miniaturization of mechanochemical reactions could also be an alternative to working with precious or expensive reagents and to facilitate monitoring of the reactions [ 27 ].…”

In Situ Analytical Methods for the Characterization of Mechanochemical Reactions

“…The sample fractions staying close to the two opposite walls cause reflections that appear at different angles depending on which side of the vessel they originate. To overcome this problem, Lampronit et al designed miniaturized 1.8 mL PMMA milling vessels [53]. In combination with an optimized sample positioning, they could improve data quality and avoid intensive peak splitting due to "sample displacement" or diffraction from samples adhered at the opposite walls of the jar.…”

Mechanochemical Synthesis of Fluorine-Containing Co-Doped Zeolitic Imidazolate Frameworks for Producing Electrocatalysts

“…Zinc oxide (0.337 mmol, 27.4 mg), zinc acetate dihydrate (10 mol% of total metal content, 0.037 mmol, 8.2 mg), 2-methylimidazole (0.748 mmol, 61.4 mg), and NH 4 NO 3 (0.748 mmol, 3.0 mg) were placed into a custom-made milling jar (PMMA, 5 mL) ( Lampronti et al, 2021 ). After adding one stainless-steel milling ball (7-mm diameter) and methanol (15 µL), the jar was closed and mounted into a vertical ball mill (Pulverisette 23; Fritsch GmbH, Idar-Oberstein, Germany).…”