Metal–organic frameworks (MOFs) are emerging as sustainable reagents and catalysts with promising applications in synthetic chemistry. Although the hydrothermal stabilities of MOFs have been well studied, their robustness toward various reagents, including acids, bases, nucleophiles, electrophiles, oxidants, and reductants, remains poorly characterized. As such, heterogeneous platforms for promising catalysts are generally identified on an ad hoc basis and have largely been limited to carboxylate frameworks to date. To address these limitations, here we systematically characterize the robustness of 17 representative carboxylate, salicylate, and azolate MOFs toward 30 conditions representing the scope of synthetic organic chemistry. Specifically, analysis of the full width at half-maximum of powder X-ray diffraction patterns, as well as infrared spectroscopy, 77 K N2 adsorption measurements, and scanning electron microscopy in select cases are employed to appraise framework degradation and dissolution under a range of representative conditions. Our studies demonstrate that azolate MOFs, such as Fe2(bdp)3 (bdp2– = 4,4′-(1,4-phenylene)­bis­(pyrazolate)), generally possess excellent chemical stabilities under myriad conditions. In addition, we find that carboxylate and salicylate frameworks possess complementary stabilities, with carboxylate MOFs possessing superior robustness toward acids, electrophiles, and oxidants, and salicylate MOFs demonstrating improved robustness toward bases, nucleophiles, and reductants. The guidelines provided herein should facilitate the rational design of robust frameworks for applications in synthetic chemistry and guide the development of new strategies for the postsynthetic modification of MOFs as well.

Metal–organic frameworks (MOFs) are crystalline, porous solids constructed from organic linkers and inorganic nodes that are promising for applications in chemical separations, gas storage, and catalysis, among many others. However, a major roadblock to the widespread implementation of MOFs, including highly tunable and hydrolytically stable Zr- and Hf-based frameworks, is their benchtop-scalable synthesis, as MOFs are typically prepared under highly dilute (≤0.01 M) solvothermal conditions. This necessitates the use of liters of organic solvent to prepare only a few grams of MOF. Herein, we demonstrate that Zr- and Hf-based frameworks (eight examples) can self-assemble at much higher reaction concentrations than are typically utilized, up to 1.00 M in many cases. Combining stoichiometric amounts of Zr or Hf precursors with organic linkers at high concentrations yields highly crystalline and porous MOFs, as confirmed by powder X-ray diffraction (PXRD) and 77 K N2 surface area measurements. Furthermore, the use of well-defined pivalate-capped cluster precursors avoids the formation of ordered defects and impurities that arise from standard metal chloride salts. These clusters also introduce pivalate defects that increase the exterior hydrophobicity of several MOFs, as confirmed by water contact angle measurements. Overall, our findings challenge the standard assumption that MOFs must be prepared under highly dilute solvothermal conditions for optimal results, paving the way for their scalable and user-friendly synthesis in the laboratory.

Metal–organic frameworks (MOFs) are crystalline, porous solids constructed from organic linkers and inorganic nodes that are promising for applications in chemical separations, gas storage, and catalysis, among many others. However, a major roadblock to the widespread implementation of MOFs, including highly tunable and hydrolytically stable Zr- and Hf-based frameworks, is their benchtop-scalable synthesis, as MOFs are typically prepared under highly dilute (≤0.01 M) solvothermal conditions. This necessitates the use of liters of organic solvent to prepare only a few grams of MOF. Here-in, we demonstrate that Zr- and Hf-based frameworks (eight examples) can self-assemble at much higher reaction concen-trations than are typically utilized, up to 1.00 M in many cases. Combining stoichiometric amounts of Zr or Hf precursors with organic linkers at high concentrations yields highly crystalline and porous MOFs, as confirmed by powder X-ray diffraction (PXRD) and 77 K N2 surface area measurements. Further, the use of well-defined pivalate-capped cluster pre-cursors avoids the formation of ordered defects and impurities that arise from standard metal chloride salts. These clus-ters also introduce pivalate defects that increase the exterior hydrophobicity of several MOFs, as confirmed by water con-tact angle measurements. Overall, our findings challenge the standard assumption that MOFs must be prepared under highly dilute solvothermal conditions for optimal results, paving the way for their scalable and user-friendly synthesis in the laboratory.

Polyethylene terephthalate (PET) fibers are among the largest plastics in production. Used commonly in textiles, PET fibers are often blended with non-PET components such as cotton, dyes, and additives. As these non-PET components generate impurities during depolymerization, extracting a high-purity terephthalic acid (TPA) monomer from the chemical recycling of textiles is challenging. Here, we demonstrate the extraction of high-quality TPA from the impure crude digestion mixtures containing depolymerized PET fibers and non-PET components. Our approach uses reactive crystallization to turn TPA into a metal−organic framework (MOF). As TPA is the only component in the mixture capable of forming an extended, crystalline structure, TPA monomers are separated from impurities as MOF crystallizes. We demonstrate this concept on recycled TPA (rTPA) extracted from a polyester−cotton blend textile through alkaline hydrolysis, where the impure rTPA was used as an organic linker to prepare MOF . This MOF crystallization removed the trapped impurities. After MOF disassembly, colorless TPA, reminiscent of a virgin-grade monomer, was obtained (yield: 78%). These results demonstrate self-assembly-induced crystallization as a new strategy to selectively recover monomers from complex mixtures.