RSC Mechanochemistry最新文献

Amorphous-to-crystalline transformation is of profound importance in the crystallization of covalent organic frameworks (COFs), yet its potential through solid-state mechanochemistry remains largely unexplored. Here, we introduce a mechanochemical amorphous-to-crystalline pathway to synthesize imine-linked COFs under ambient conditions. By ball milling their amorphous progenitors, nine imine-linked COFs with distinct core structures, topologies (hcb, sql, kgm, and dia), and dimensions are constructed in as little as one hour. Notably, the unique advantage of this method is highlighted by the successful synthesis of a highly crystalline, porous pyrene-based COF inaccessible by de novo mechanosynthesis. A mechanochemical "scrambling" reaction of imine-based model compounds confirms the high reversibility of the imine bonds in the solid state, which is crucial for facilitating error correction during COF reconstruction. This study underscores mechanochemistry as an effective means for amorphous-to-crystalline transformation, establishing a facile, generic, and green pathway to imine-linked COFs, including those unattainable via conventional de novo mechanosynthesis.

In this work, the influence of milling ball properties on energy transfer and mixing efficiency was systematically investigated by decoupling mass, surface area, and kinetic energy. To achieve this, hollow and solid balls of different sizes were employed, allowing independent variation of these parameters. Additionally, cylindrical and round-ended milling tools were additionally used to study the effects of surface geometry and contact dynamics. Yield normalization by energy input, ball mass, and surface area enables clearer correlation between individual ball characteristics and milling efficiency. This approach provides a more detailed understanding of how individual mechanical properties contribute to overall process performance.

The International Symposium on Mechanochemistry (Mech'cheM 2025) took place in Montpellier (France) June 4-6, 2025, gathering 145 mechanochemists across the disciplines. Ten years after Mech'cheM 2015, it was an occasion to assess new progress and developments in the field. In this article, we highlight the main features of the plenary lectures and oral communications, illustrating the dynamic current cutting-edge research activities together with significant applications across the field of chemistry.

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In this effort, a solvent-free, media-free, mechanochemical route is used to accelerate the synthesis and exploration of an energetic oxidizer : fuel complex. Using magnesium nitrate hexahydrate and glycine as our example, we demonstrate that water from the metal salt is shed with moderate energy input and drives liquid-assisted mechanochemistry. This route reduces synthesis time from days to hours and shows promise for a host of metal salt complexes.

Mechanochemistry has become a powerful and sustainable approach in synthetic chemistry, yet the fundamental principles governing energy transfer during milling remain poorly understood. In particular, the trajectory of the milling ball has been largely overlooked in mechanistic studies. To address this, we employed high-speed recordings to precisely track ball motion, enabling accurate calculation of kinetic energies and their comparison with theoretical values. The use of hollow and solid balls of varying sizes further allowed us to disentangle the effects of altered trajectories in both the Finkelstein reaction and the direct mechanocatalyzed Suzuki coupling. This work underscores the critical importance of milling ball trajectory in mechanochemistry and highlights the need to consider this parameter in future mechanistic studies and in the development of optimized milling protocols.

Recognized as the most stable phase of uranium oxide, α-U₃O₈ is widely used throughout the nuclear fuel cycle for safe storage and transportation. There is, however, a lack of understanding of the thermodynamic relationship between α-U₃O₈ and its polymorph, β-U₃O₈. This research contributes new knowledge regarding the kinetics and mechanism of a previously described mechanochemical phase transition between the α- and β-U₃O₈ polymorphs to improve the understanding of their thermodynamic relationship. In this work, tumble milling of α-U₃O₈ using different milling media shows an ingrowth of the β-phase over time, with an observed correlation between media density, percent conversion and lattice strain. Anisotropic peak broadening observed within collected X-ray diffraction powder patterns suggests the preservation of uranium polyhedral layered sheets throughout the milling process. Preservation of the sheets implies a shear-induced slip mechanism occurring through in-plane shifting of uranium polyhedra along lattice planes perpendicular to the polyhedral sheets.

Mechanochemistry has emerged as a powerful and environmentally benign alternative to conventional solution synthesis. In this study, we present a comprehensive investigation into the solid-state mechanochemical synthesis of a diverse library of palladium(II) complexes. This investigation utilized five commercially available Pd(II) precursors and twelve diene, N- and P-donor ligands. Systematic investigations have revealed that high-yielding and clean reactions can be achieved by tuning the milling frequency, reaction time, and metal-to-ligand stoichiometry, affording more than forty Pd(II) complexes. A comparison with conventional solution-based protocols is therefore indicated to underscore the operational simplicity and ecological advantage of the mechanochemical approach, as demonstrated by favorable green chemistry metrics such as low E-factors and high effective mass yields (EMYs). The validity of the methodology was established through gram-scale syntheses, which demonstrated high yields and reproducibility. These findings contribute a robust and generalizable synthetic strategy for accessing widely used palladium precursors, thus supporting the integration of mechanochemistry into green organometallic synthesis.

We report a novel rapid synthesis method for Ba-doped BiCuSeO using mechanochemical synthesis. The phase formation mechanism during high-energy milling as well as the combined effects of the powder-to-ball mass ratio and the heterovalent substitution of bismuth by barium on the thermoelectric properties was investigated. It was shown that the single-phase oxyselenide compounds are formed after 25 minutes of ball milling. The thermoelectric properties of these samples were found to be comparable with the properties of oxyselenides prepared via conventional solid-state reaction reported in the literature.

Mechanochemical methods such as ball milling offer a solvent-free and non-thermal approach for PFAS remediation, enabling not just separation but actual destruction of PFAS through defluorination. In this study, we demonstrate that effective PFAS defluorination using ball milling critically depends on the presence of a co-milling catalyst, in this case piezoelectric catalysts such as boron nitride (BN), which showed the highest performance among other tested piezoelectric materials. While BN has already proven effective for defluorination of pure PFAS compounds, PFAS in sediments, and aqueous film-forming foam (AFFF), prior studies have been limited by the small amounts of PFAS they can treat inside another medium. To overcome these limitations, we present as an alternative the coupling of BN with activated carbon as a pre-concentration medium for PFAS. By leveraging activated carbon's high sorption capacity, we were able to destroy nearly 100 times higher mass of PFOA in less than one-third of the time compared to previous studies on sediments or AFFF. These results suggest that the design of larger-scale ball milling systems for PFAS destruction should incorporate the use of high-capacity sorbents to concentrate contaminants, thus destroying higher amounts more effectively. While in the case of activated carbon the chances of reusing it after milling are minimal, it could be safely disposed of without the risk of releasing PFAS back into the environment.