Mechanochemical synthesis of mixed metal, mixed linker, glass-forming metal-organic frameworks

Current methodologies to produce glass forming metal-organic frameworks (MOFs) rely on non-scalable solvothermal syntheses which have high energy requirements, relatively low yields and large teratogenic solvent usage. Here we use a mechanochemical method to produce the glass-forming MOFs, ZIF-62 and ZIF-UC-5, in 30 minutes at room temperature, using microlitre quantities of solvent and stoichiometric amounts of organic linkers. This method facilitates the accurate synthesis of ZIF-62 structures containing both Co and Zn, allowing the effect of metal-ion dopant upon melting temperature to be studied for the first time. Further to this, we present variable organic linker ratio series of ZIF-62 and of ZIF-UC-5. The specific composition of the materials in the series is made possible by the mechanochemical method. We also present a greener solvothermal method to form ZIF-62, which is capable of producing crystalline materials of suffcient quality for single crystal diffraction experiments.