Solvent Impact on the Properties of Benchmark Metal–Organic Frameworks: Acetonitrile‐Based Synthesis of CAU‐10, Ce‐UiO‐66, and Al‐MIL‐53. Issue 17 (9th March 2020)

• Record Type: Journal Article
• Authors: Leubner, Sebastian; Stäglich, Robert; Franke, Julia; Jacobsen, Jannick; Gosch, Jonas; Siegel, Renée; Reinsch, Helge; Maurin, Guillaume; Senker, Jürgen; Yot, Pascal G.; Stock, Norbert
• Is Part Of: Chemistry. Volume 26:Issue 17(2020)
• Page Start: 3877
• Page End: 3883
• Publication Date: 2020-03-09
• Subjects: adsorption -- metal–organic frameworks -- microporous materials -- NMR spectroscopy -- solvent effects; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201905376
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Herein is reported the utilization of acetonitrile as a new solvent for the synthesis of the three significantly different benchmark metal–organic frameworks (MOFs) CAU‐10, Ce‐UiO‐66, and Al‐MIL‐53 of idealized composition [Al(OH)(ISO)], [Ce6 O4 (OH)4 (BDC)6 ], and [Al(OH)(BDC)], respectively (ISO 2− : isophthalate, BDC 2− : terephthalate). Its use allowed the synthesis of Ce‐UiO‐66 on a gram scale. While CAU‐10 and Ce‐UiO‐66 exhibit properties similar to those reported elsewhere for these two materials, the obtained Al‐MIL‐53 shows no structural flexibility upon adsorption of hydrophilic or hydrophobic guest molecules such as water and xenon and is stabilized in its large‐pore form over a broad temperature range (130–450 K). The stabilization of the large‐pore form of Al‐MIL‐53 was attributed to a high percentage of noncoordinating −COOH groups as determined by solid‐state NMR spectroscopy. The defective material shows an unusually high water uptake of 310 mg g −1 within the range of 0.45 to 0.65 p/p°. In spite of showing no breathing effect upon water adsorption it exhibits distinct mechanical properties. Thus, mercury intrusion porosimetry studies revealed that the solid can be reversibly forced to breathe by applying moderate pressures (≈60 MPa). Abstract : Metal–organic frameworks : CAU‐10, Ce‐UiO‐66, and Al‐MIL‐53 were synthesized by utilizing acetonitrile as the solvent. The typical breathing behavior of Al‐MIL‐53 upon guest molecule adsorption was inhibited by a high concentration of defects. As shown by NMR spectroscopy these consist of noncoordinated −COOH groups. Breathing could be enforced by applying a pressure of about 60 MPa during mercury intrusion.