Single- and Mixed-Linker Cr-MIL-101 Derivatives: A High-Throughput Investigation

Abstract

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.

Synthesis and Characterization of Amine-Functionalized Mixed-Ligand Metal–Organic Frameworks of UiO-66 Topology

“…[22][23][24][25] Furthermore, varying the composition of mixed linkerMOFs can result in systematic alteration of the gas adsorption capacity and selectivity of the material. Such an approach has been previously been adopted on several MOF topologies, namely MOF-5, 26 MIL-53-Al, [27][28] CAU-10, 29 and MIL-101 30 where a mixture of benzene-1,4-dicarboxylic acid (BDC) and its amino-, bromo-, nitro-, methyl-functionalized derivatives were used as linkers. In these studies, various properties of the materials were significantly influenced by the amount and type of functionality introduced in to the framework; namely the surface area (MOF-5), 26 the breathing pressure (MIL-53) 28 and sorption properties (CAU-10) 29 were observed to have been affected.…”

Discovery of New Calcium Etidronates Employing Ultrasound Adapted High-Throughput Methods

“…In the syntheses of inorganic−organic hybrid compounds various parameters have been systematically investigated for example reactant concentrations, 25 pH, 26 ionic radii of the metal ions, 27 or the length or functionality of the organic moiety. 15,28,29 The synthesis of inorganic−organic hybrid compounds has been explored with high-throughput methods in solvothermal reactions using conventional electric, and recently microwave assisted dielectric heating has also been employed. 14,27,30 Syntheses applying ultrasound (US) make often use of the high temperatures (5000 K) and high pressures (>1000 atm) that occur in local "hot spots" which are due to cavitation.…”

Influence of Strong Electronegativity Groups -Cl as the Adsorption Center of PTA@MIL-101-NH²-Cl for the Selective Hydrolysis of Cellulose into Glucose

“…The bands at 3468 cm -1 and 3358 cm -1 corresponded to -NH 3 + stretching vibration. The bands at 1257 cm -1 and 1050 cm -1 belonged to C-N and C-Cl stretching vibration [24]. It can be seen from Fig.2 that the adsorption peak of the catalyst containing PTA @ MIL-101-NH 2 -Cl at 1050 cm -1 indicates that -Cl is present in the catalyst which proved -Cl is successfully grafted.…”