UiO-67-type Metal–Organic Frameworks with Enhanced Water Stability and Methane Adsorption Capacity

Abstract

The structure and properties of two new UiO-67-type metal-organic frameworks, along with their linker synthesis and powder and single crystal synthesis, are presented. The new MOFs, UiO-67-Me and UiO-67-BN, are based on 3,3'-dimethylbiphenyl and 1,1'-binaphthyl linker scaffolds, and show a much higher stability to water than the thoroughly investigated UiO-67, which is based on the biphenyl scaffold. On the basis of structure models obtained from single crystal X-ray diffraction, it is seen that these linkers are partly shielding the Zr cluster. The new materials have higher density than UiO-67, but show a higher volumetric adsorption capacity for methane. UiO-67-BN exhibits excellent reversible water sorption properties, and enhanced stability to aqueous solutions over a wide pH range; it is to the best of our knowledge the most stable Zr-MOF that is isostructural to UiO-67 in aqueous solutions.

Stable Metal–Organic Frameworks: Design, Synthesis, and Applications

“…Thus, to obtain stable MOFs, researchers choose to construct frameworks with carboxylate‐based ligands (hard Lewis bases) and high‐valent metal ions (hard Lewis acids), or azolate‐based ligands (soft Lewis bases) and low‐valency transition metal ions (soft Lewis acids). Guided by this strategy ( Scheme ), dozens of MOFs with excellent stability were obtained …”

Metal–Organic Frameworks for Water Harvesting from Air

“…The isoreticular expanded version of UiO‐66 (UiO‐67 [Zr 6 O 4 (OH) 4 (BPDC) 6 ] where BPDC = biphenyl‐4,4′‐dicarboxylate) displays a significantly lower stability toward water than the parent isoreticular UiO‐66. The original stability can be restored by virtue of appending large substituents to the BPDC linker to effectively increase steric shielding, an effect that will be discussed later in more detail . MOFs built from infinite, rod‐like SBUs are often exceptionally stable because of steric shielding by the binding groups.…”

Strongly visible light-absorbing metal–organic frameworks functionalized by cyclometalated ruthenium(ii) complexes

“…All chemicals were used as received. UiO-67, 35,49 UiO-67-bpy, 41 single crystals of UiO-67-Me 2 -bpy, 50 and all ruthenium complexes 36,51 were synthesized as previously reported. Centrifugation of samples was done using 15 mL centrifuge tubes (60 mL sample glass for the rst centrifugation of the postsynthetic linker exchange samples) and a Heraeus Labofuge 400 instrument from Thermo Scientic at 3000 rpm for 10 min.…”

“…The structure solution and renement clearly showed the structure of UiO-67-Me as previously published. 50 Trying to rene the structure without ruthenium clearly revealed the presence of electron density close to the center of the linker, on the expected location of Ru coordinated to a bipyridine linker. Fig.…”