Formation and characterisation of Mn-MIL-100

Abstract

The synthesis and characterisation of the Mn-based analogue of the MIL-100 framework is reported. The title compound is synthesised from a methanolic solution of trimesic acid and manganese(II) nitrate in very short reaction times. During the reaction, the Mn²⁺ ions are oxidized in situ to Mn³⁺ ions. The obtained MOF was characterised by XRPD measurements, IR spectroscopy, thermogravimetric measurements and sorption experiments. To have a closer look at the crystallisation occurring after the in situ metal oxidation reaction that results in the formation of the title compound, in situ EDXRPD experiments under solvothermal conditions were carried out. These time-resolved measurements could be evaluated by two different kinetic models (by Avrami and Gualtieri) for crystallisation. The results indicate a two stage reaction process, which is dominated by different reaction mechanisms.