Tailoring the water adsorption properties of MIL-101 metal–organic frameworks by partial functionalization

Abstract

MIL-101 and MIL-101-NH 2 were partially modified to incorporate various functional groups that are capable of forming hydrogen bonds with water. Specifically, MIL-101-NH 2 was partially functionalized with -NHCONHCH 2 CH 3 (-UR2), -NHCOCHCHCOOH (-Mal), or -NH(CH 2 ) 3 SO 3 H (-3SO 3 H) and MIL-101 was partially functionalized with -COOH in order to investigate the effect of these groups on the water sorption properties when compared to the pristine versions. The MIL-101 derivatives were synthesized by either post-synthetic modification of MIL-101-NH 2 or through direct synthesis using a mixed linker strategy. The ratios of the incorporated functional groups were determined by 1 H-NMR analyses and the porosity changes were revealed by N 2 gas adsorption measurements at 77 K. Water sorption isotherms at 298 K conclude that the incorporation of -3SO 3 H enhances the water vapour uptake capacity at a low relative pressure (P/P 0 ¼ 0.30), whereas -UR2 and -Mal retard water adsorption in MIL-101-NH 2 . The partial incorporation of -COOH in MIL-101 exhibits a steeper water uptake at lower pressure (P/P 0 ¼ 0.40) than MIL-101-NH 2 . Interestingly, a greater -COOH content within the MIL-101 framework reduces the water uptake capacity. These results indicate that even partial functionalization of MIL-101 induces noticeably large changes in the water adsorption properties.

Synthesis Optimization, Shaping, and Heat Reallocation Evaluation of the Hydrophilic Metal–Organic Framework MIL‐160(Al)

“…With the exception of MIL-127(Fe), the water-sorption properties of these MOFs were previously reported, [3,12,17,[30][31][32][33][34][35] with interesting results in terms of water-sorptionc apacity and lowtemperature regeneration. Moreover, the hydrophilic character of someM OFs [MIL-125(Ti)-NH 2 ,U iO-66(Zr)-NH 2 ]c ould be enhanced throught he introduction of hydrophilic amino groups on the organic spacer.H erein, we aimed to comparet hese MOFs and zeolite 13X [29] (see Table 1) as potential physicala dsorbentm aterials fore nergy-storage applications (the full characterization of the MOFs is given in the Supporting Information, Figures S1-S23).W ef irst measuredt heir cycling loading lifts using the typical conditions of as easonal energy-storage device.…”

Ethylene diamine post‐synthesis modification on open metal site Cr‐MOF to access efficient bifunctional catalyst for the Hantzsch condensation reaction

“…12 and 16 Å . Also OMS‐MIL‐101(Cr) with unsaturated cluster of Cr 3 O +7 are ideal platform for post‐synthetic modification (PSM) reactions, and therefore is an interesting candidate for catalytic aims. Wang and co‐worker have recently reported a simple post‐synthetic modification strategy was employed for the rapid and facile introduction of primary alkyl amino group .…”

Metal–Organic Frameworks for Water Harvesting from Air

“…Hydrophilic substituents shift the inflection point of the isotherm lower (a–d), hydrophobic groups to higher P / P 0 values (e), and hydroneutral groups have a negligible effect on the position of the inflection point (f). In all cases substitution leads to a decrease in maximum capacity, arguably due to the decreased pore volume …”

“…The effect of functional groups on the water adsorption properties of MIL‐101 was studied by partial incorporation of chemically modified linkers bearing functional groups capable of interacting with water . The BDC linker in (Cr)MIL‐101 was partially functionalized with COOH ( 1 ), NH 2 ( 2 ), NHCONHCH 2 CH 3 ( 3 ), NHCOCHCHCOOH ( 4 ), and NH(CH 2 ) 3 SO 3 H ( 5 ).…”