engleski

New Mechanochemical Methodologies for Advanced Reactivity in Coordination and Organic Chemistry

Mechanochemical and vapor-induced transformations of solids are emerging as green and energy- efficient synthetic alternatives to classic solution procedures. Despite their growing importance and wide application to variety of materials, from inorganic nanoparticles to soft supramolecular solids, mechanisms and kinetics of these solvent-free reactions are only now becoming unveiled through development of in situ monitoring methods based on powder X-ray diffraction (PXRD) [1, 2] Raman spectroscopy, [3] and high-precision temperature monitoring.[4] These advanced techniques, used either alone or in tandem, allowed for real-time insight into the course of these solid-state reactions without the need to interrupt them for sampling, gaining unprecedented data about the mechanisms and kinetics of the monitored reactions. This talk will focus on several archetypal organic or coordination reactions where the in situ monitoring revealed rich variety of mechanisms, often involving solid-state selectivity, amorphization, recrystallization, and various phase transformations, together with the emergence of new and unknown intermediate phases. These intermediates can be exploited for the preparation of non-standard materials which are not accessible by other preparation techniques, such as multi- metallic MOF-74 derivatives. We used solid-state NMR to determine the exact tautomeric form of the products, and also to elucidate the distribution and local mode of coordination to the metal center in the MOF. This is possible even when the centers are paramagnetic, revealing the homogeneity of distribution of metal centers and assisting in the rationalization of the observed magnetic properties of this important subclass of MOF materials.

Mechanochemistry ; coordination compounds polymorphism ; organic synthesis

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