Cooperative Cluster Metalation and Ligand Migration in Zirconium Metal–Organic Frameworks

Abstract

Cooperative cluster metalation and ligand migration were performed on a Zr-MOF, leading to the isolation of unique bimetallic MOFs based on decanuclear Zr6M4 (M = Ni, Co) clusters. The M(2+) reacts with the μ3-OH and terminal H2O ligands on an 8-connected [Zr6O4(OH)8(H2O)4] cluster to form a bimetallic [Zr6M4O8(OH)8(H2O)8] cluster. Along with the metalation of Zr6 cluster, ligand migration is observed in which a Zr-carboxylate bond dissociates to form a M-carboxylate bond. Single-crystal to single-crystal transformation is realized so that snapshots for cooperative cluster metalation and ligand migration processes are captured by successive single-crystal X-ray structures. In(3+) was metalated into the same Zr-MOF which showed excellent catalytic activity in the acetaldehyde cyclotrimerization reaction. This work not only provides a powerful tool to functionalize Zr-MOFs with other metals, but also structurally elucidates the formation mechanism of the resulting heterometallic MOFs.

Selective Gold Recovery and Catalysis in a Highly Flexible Methionine-Decorated Metal–Organic Framework

“…In the same way that other porous materials, 16,17 MOFs have proven their efficiency as vessels to capture and host small molecules, 18 and eventually, to separate mixtures of molecules according to their steric and stereochemical features as well as reactivity properties (functional substituent groups). [19][20][21][22] Despite the fact that a few examples of selective metal capture by MOFs have been reported, 23 to the best of our knowledge, the important recovery of Au has not been studied. Aiming at expanding the scope of application of MOFs and taking advantage of the well-known strong affinity of gold for sulfur derivatives, 24,25 we have focused our efforts on the rational design of bioMOFs showing functional channels decorated with thio-alkyl chains derived from the natural amino acid 26 L-methionine (Scheme S1).…”

Size effect of the active sites in UiO-66-supported nickel catalysts synthesized via atomic layer deposition for ethylene hydrogenation

“…15 The decoration can be accomplished via A LD i n M OFs (AIM) 16–18 or s olvothermal deposition i n M OFs (SIM) 19–22 —as well as by AIM and SIM in combination. 23 Depending, of course, on their specific chemical composition, the resulting MOF-supported clusters or single metal ions can be rendered competent for photocatalytic H 2 generation, 24 electrocatalytic O 2 production, 25 solution-phase alkene epoxidation, 26, 27 and gas-phase ethylene hydrogenation and oligomerization, 13, 21, 28 hexene polymerization, 20 and propane oxidative dehydrogenation, 29 among other reactions.…”

“…36 Due to the structural uniformity of the MOF supports, 37 the metal ions installed on nodes of MOFs, via AIM or SIM, tend to adopt, for a given set of synthesis conditions, well-defined structures of uniform size. 22 Intentional modulation of the size of AIM-installed clusters can be achieved varying the number AB synthesis cycles.…”

“…(In contrast, mesoporous Zr-MOFs such as PCN-222 (MOF-545), 42, 43 NU-1000, 16 NU-1200, 44 and MOF-808 45 are six- or eight-connected, with the unused linker-connection sites instead being occupied by ligated water or hydroxide, i.e. ligands that are ideal for reacting with metal ions (SIM) 22 or metal-containing ALD precursors (AIM and SIM). 23, 26 ) Real UiO-66 samples, in contrast, are characterized by missing linkers, 46 leaving the nodes eleven- (or ten-) connected.…”

Photoresponsive spiropyran-functionalised MOF-808: postsynthetic incorporation and light dependent gas adsorption properties

“…24 In the present study, a novel spiropyran with a short-chain carboxylic acid (acetate) and a nitro group positioned at R 1 and R 2 , respectively, was designed and targeted (2-(3 0 ,3 0 -dimethyl-6nitrospiro-[chromene-2,2 0 -indolin]-1 0 yl)acetic acid, SP). 2a, [Zr 6 O 4 (OH) 4 -(btc) 2 (HCOO) 6 ]) was chosen as a PSM platform for the following reasons: (1) the high oxidation state of Zr IV enables strong metal-ligand bonds, making MOF-808 highly chemically robust, and thus permitting the installation and further chemical modication of the spiropyran functional groups; [27][28][29][30] (2) MOF-808 possesses sufficiently large cavities to accommodate the SP molecule (ca. 5 The zirconium-based MOF-808 25,26 (Fig.…”