A stepwise mechanism and the role of water in the liquid-assisted grinding synthesis of metal–organic materials

Rapid Room‐Temperature Synthesis of Zeolitic Imidazolate Frameworks by Using Mechanochemistry

“…[19] This is consistent with a mass action effect at early stages of the reaction: the high initial ratio of liquid to solid would favor a structure that binds a large amount of solvent. [20] Stepwise behavior was also observed for ILAG reactions with NH 4 CH 3 SO 3 but with lower rates of interconversion: the RHO topology persisted up to 20 min grinding in mixture with ANA, and the qtz topology was observed after 60 min grinding with DMF (Figure 2 c). With DEF as the grinding liquid, the ANA topology was the only product even after 60 min grinding.…”

Clean and Efficient Synthesis Using Mechanochemistry: Coordination Polymers, Metal-Organic Frameworks and Metallodrugs

“…In support of this hypothesis, we also explored the water catalyzed reaction of copper(II) oxide, CuO, with acetic acid (AcOH) at short reaction times. 50 In accordance with the proposed stepwise mechanism the reaction was found to proceed via an acetic acid solvate of the copper(II) acetate 52 paddlewheel dimer which subsequently transformed into the final product copper(II) acetate hydrate (Figure 6b). …”

“…50 This observation suggests a mass-action effect in LAG synthesis of coordination polymers, in which the relatively large amount of a liquid phase early in the reaction leads to the formation of a highly solvated product. Subsequently, this intermediate transforms into a final product whose composition is dictated by the stoichiometric composition of the reaction mixture.…”

“…49 The quantitative reaction yields enabled the collection of high-quality PXRD data, suitable for the structural characterization of these previously not known materials. 48 The formation of different zinc fumarate coordination polymers by grinding with a different liquid phase was subsequently rationalized 50 in a study using different mixtures of alcohols and water as grinding liquids. The composition of the product was found to be strongly correlated to the activity of water in the grinding liquid, pointing towards a rational strategy to mechanochemically screen for hydrated coordination polymers by varying the activity of water in the grinding liquid.…”

Mechanochemistry: opportunities for new and cleaner synthesis

“…[291] Subsequent study revealed that the formation of different products can be correlated with the activity of water in the grinding liquid, and that LAG with pure water proceeds in a stepwise fashion. [292] A crystalline hydrate forms first, which depletes the free water in the mixture so as to change the liquid-assisted reaction into a neat grinding process ( Figure 15). The latter is speculated to proceed through an amorphous intermediate, deduced by the spontaneous formation of different coordination polymers by ageing of the partially reacted reaction mixture ( Figure 15).…”