For the first time, functionality has been covalently introduced into the Cr-MIL-101 network by post-synthetic modification of the terephthalate linker molecule through nitration. The nitro group was reduced and the amino group was reacted with ethyl isocyanate to yield the corresponding urea derivative.

New single- and mixed-linker Cr-MIL-101 derivatives bearing different functional groups have been synthesized. The influence of the reaction parameters, such as metal source (CrO3, CrCl3, and Cr(NO3)3·9H2O) or linker composition, on product formation have been investigated using high-throughput methods. Highly crystalline Cr-MIL-101 materials were obtained with CrCl3 as the metal source with either 2-bromoterephthalic (TA-Br) or 2-nitroterephthalic (TA-NO2) acid as one of the mixed-linker components. On the basis of these results, numerous new mixed-linker Cr-MIL-101 derivatives containing -NH2, -NO2, -H, -SO3H, -Br, -OH, -CH3, and -COOH have been synthesized. The use of TA-NH2 and TA-OH were shown, under the same reaction conditions, to lead to decarboxylation and the formation of 3-amino- and 3-hydroxybenzoic acid, respectively. Furthermore, we were also able to directly synthesize single-linker Cr-MIL-101-X derivatives with X = F, Cl, Br, CH3. Postsynthetic modification was used to selectively reduce the mixed-linker compound Cr-MIL-101-Br-NO2 to Cr-MIL-101-Br-NH2. To establish the successful incorporation of the linker molecules and possible decomposition of certain starting materials, (1)H NMR spectra of dissolved reaction products were recorded.

We report the synthesis and characterization of the new switchable Zn‐based zeolitic imidazolate framework (ZIF) [Zn(Im)(aIm)] (1). The high‐throughput investigation of the mixed linker system Zn2+/imidazole (HIm)/2‐phenylazoimidazole (HaIm)/DMF at 85 °C led to 1, which is isostructural to ZIF‐8 and crystallizes in a sodalite (SOD)‐type structure. The preparation was also studied with microwave‐assisted heating and ultrasound‐assisted synthesis. The crystal structure was determined from single‐crystal X‐ray diffraction data. Although Im– and aIm– ions are present in a 1:1 molar ratio, no ordering of the 2‐phenylazo group was observed. Incorporation of the Im– and aIm– linkers as an integral part of the framework structure was confirmed by elemental analysis, 13C and 15N MAS NMR, IR and Raman spectroscopy. In addition, the permanent porosity of 1 was demonstrated by N2 sorption experiments and a specific surface area of SBET = 580 m2 g–1 is observed. The photoswitching properties were investigated by UV/Vis spectroscopy as the cis and trans isomers exhibit different UV absorption spectra. Switching can be achieved by irradiation with UV light (λ = 355 nm), and back‐switching using visible light (λ = 525 nm). Although changes in the UV/Vis spectra are detected, the switching process is only partially reversible.

A crystal-like ordered microporous inorganic hybrid solid was prepared using silane functionalized Cr-MIL-101 (Si-MIL-101) as the precursor, via a surface coating reinforced framework strategy.