Exploiting In-Situ NMR to Monitor the Formation of a Metal-Organic Framework

The formation processes of metal-organic frameworks are increasingly widely researched using in-situ techniques, although there remains a scarcity of NMR studies in the field. In this work, the synthesis of MFM-500(Ni) has been investigated using the Combined Liquid- And Solid-State In‑situ Crystallization NMR strategy, which provides information on the time-evolution of both solid and liquid phases during crystallization. In our NMR study, the liquid-phase NMR data recorded as a function of time at five fixed temperatures afford qualitative information on the solution-phase processes and quantitative information on the kinetic parameters of crystallization, allowing the activation energies for nucleation and growth to be determined. Ex-situ SAXS studies provide complementary nanoscale information on the rapid self-assembly prior to crystallisation, and in-situ PXRD confirms that the only crystalline phase present during the reaction is phase-pure MFM-500(Ni).