Greener solvent strategies for sustainable metal–organic framework synthesis: properties, solvent–framework interactions, and applications

The properties of metal–organic frameworks (MOFs) render them highly promising across multiple fields, yet their environmental impact during synthesis remains insufficiently acknowledged. Current mainstream approaches still rely on highly toxic solvents such as N,N-dimethylformamide (DMF) or N-methylpyrrolidone (NMP), whose presence significantly impacts both the natural environment and human health. This bottleneck signifies that solvents are no longer merely auxiliary factors but have become a critical variable determining whether MOFs can progress beyond the laboratory. This article systematically evaluates the environmental and health burdens imposed by conventional hazardous solvents during MOF synthesis and examines greener solvent strategies for more sustainable MOF preparation. Particular emphasis is placed on methanol and ethanol, which are widely available commodity solvents that can be produced from either fossil-derived or renewable feedstocks, and on Cyrene, an explicitly bio-derived solvent produced from cellulose-derived biomass. Their physicochemical properties, solvent–framework interactions, and successful applications in MOF preparation are critically assessed. Where relevant, water and aqueous or mixed-solvent systems are also discussed as broader examples of environmentally preferable solvent media; these systems are treated separately from the bio-derived solvent category. Furthermore, we demonstrate how solvent selection influences key MOF characteristics and how these effects, in turn, determine performance across various applications. We outline current hurdles and future solutions, concluding that the transition from hazardous conventional solvents toward appropriately selected greener and, where feasible, renewable solvent systems is a prerequisite for sustainable MOF manufacturing beyond the laboratory.