Kinetic Control of Metal–Organic Framework Crystallization Investigated by Time‐Resolved In Situ X‐Ray Scattering

Abstract

MOFs scattering away: The mechanism behind the multistep synthesis of two metal–organic frameworks sharing the same metal and organic precursors was revealed by in situ time‐resolved small‐ and wide‐angle X‐ray scattering. Key factors governing the crystal assembly could be established (see picture: C gray, H white, N blue, O red, Al yellow, Cl green), including solvent, temperature, and precursor concentration.

Metal organic framework based mixed matrix membranes: An increasingly important field of research with a large application potential

“…Only a small number of mono technique ex-situ crystallization studies on the synthesis of different prototypical MOFs have been reported up to date; most notably studies using X-ray absorption [105], dynamic light scattering [106], atomic force spectroscopy [107] and X-ray diffraction [108]. Only a few in situ single technique diffraction studies under hydrothermal synthesis conditions have been published [109][110][111] until the first in situ multi-technique works on more complex MOF systems were reported [112,113]. These studies might open the door to a rational design of synthesis conditions targeting specific textural properties.…”

Multi-scale crystal engineering of metal organic frameworks

“…For example, timeresolved in situ EDXRD studies of MIL-53(Fe) formation reveal the presence of the intermediated MOF-235 phase which eventually disappears on extended heating [60]. Stavitski et al [69] evaluated the crystallization pathway of NH 2 -MIL-101(Al) and NH 2 -MIL-53(Al) using in situ SAXS/WAXS, in which the appearance of the intermediate MOF-235(Al) was also observed. As evidenced, the transient intermediate 4-6 nm sized clusters of MOF-235(Al) serve as chemical reservoir for subsequent formation of the stable NH 2 -MIL-101(Al) and NH 2 -MIL-53(Al) phases.…”

Immobilization of phosphotungstic acid in an amino‐containing metal–organic framework for oxidative desulfurization

“…The reason is that NH 2 ‐MIL‐101(Al) is transformed to NH 2 ‐MIL‐53(Al) during the loading process, when it is immersed in HCl aqueous solution for 10 h (Fig. (c)) …”