Polar Molecule Confinement Effects on Dielectric Modulations of Sr-Based Metal–Organic Frameworks

The metal–organic frameworks Zr6O4(OH)4(bpydc)6 (1; bpydc2− = 2,2′-bipyridine-5,5′-dicarboxylate) and Zr6O4(OH)4(bpydc)0.84(bpdc)5.16 (2; bpdc2− = biphenyl-4,4′-dicarboxylate) were readily metalated with Ni(DME)Br2 (DME = dimethoxyethane) to produce the corresponding metalated frameworks 1(NiBr2)6 and 2(NiBr2)0.84. Both nickel(ii)-containing frameworks catalyze the oligomerization of ethylene in the presence of Et2AlCl. In these systems, the pore environment around the active nickel sites significantly influences their selectivity for formation of oligomers over polymer. Specifically, the single-crystal structure of 1(NiBr2)5.64 reveals that surrounding metal–linker complexes enforce a steric environment on each nickel site that causes polymer formation to become favorable. Minimizing this steric congestion by isolating the nickel(ii) bipyridine complexes in the mixed-linker framework 2(NiBr2)0.84 markedly improves both the catalytic activity and selectivity for oligomers. Furthermore, both frameworks give product mixtures that are enriched in shorter olefins (C4–10), leading to deviations from the expected Schulz–Flory distribution of oligomers. Although these deviations indicate possible pore confinement effects on selectivity, control experiments using the nickel-treated biphenyl framework Zr6O4(OH)4(bpdc)6(NiBr2)0.14 (3(NiBr2)0.14) reveal that they likely arise at least in part from the presence of nickel species that are not ligated by bipyridine within 1(NiBr2)5.64 and 2(NiBr2)0.84.

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Metal-Organic Frameworks

10.1021/acs.infocus.7e4004 ◽

2021 ◽

Author(s):

Lars Öhrström ◽

Francoise M. Amombo Noa

Keyword(s):

Metal Organic Frameworks ◽

Metal Organic

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Substrate templated synthesis of single-phase and uniform Zr-porphyrin-based metal–organic frameworks

Inorganic Chemistry Frontiers ◽

10.1039/c9qi01045a ◽

2020 ◽

Vol 7 (1) ◽

pp. 221-231

Author(s):

Seong Won Hong ◽

Ju Won Paik ◽

Dongju Seo ◽

Jae-Min Oh ◽

Young Kyu Jeong ◽

...

Keyword(s):

Chemical Bath Deposition ◽

Single Phase ◽

Metal Organic Frameworks ◽

Templated Synthesis ◽

Pore Structures ◽

Phase Pure ◽

Metal Organic ◽

Cbd Method

We successfully demonstrate that the chemical bath deposition (CBD) method is a versatile method for synthesizing phase-pure and uniform MOFs by controlling their nucleation stages and pore structures.

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Molecular Simulation Study of Separation of CO2 from Alkanes Using Metal-Organic Frameworks

The Journal of Physical Chemistry B ◽

10.1021/jp064376w ◽

2006 ◽

Vol 0 (0) ◽

pp. 0-0

Author(s):

S. Wang ◽

Q. Yang ◽

C. Zhong

Keyword(s):

Molecular Simulation ◽

Simulation Study ◽

Metal Organic Frameworks ◽

Metal Organic ◽

Separation Of Co2

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Synthesis of gamma-cyclodextrin based metal-organic frameworks (MOFs) to improve water quality

10.1021/scimeetings.0c02885 ◽

2020 ◽

Author(s):

Grace Tews ◽

Megan Moyer ◽

Sonja Katt

Keyword(s):

Water Quality ◽

Metal Organic Frameworks ◽

Metal Organic ◽

Improve Water Quality ◽

Gamma Cyclodextrin

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Controlling defects for smarter metal organic frameworks

Nature Middle East ◽

10.1038/nmiddleeast.2019.73 ◽

2019 ◽

Author(s):

Biplab Das

Keyword(s):

Metal Organic Frameworks ◽

Metal Organic

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Two-dimensional Metal-Organic Frameworks applied to fast-response luminescent sensing for nitro compounds in solution

10.26226/morressier.5f6c5f439b74b699bf390b0e ◽

2020 ◽

Author(s):

Caroline Moraes da Silva ◽

Guilherme Arroyos ◽

Regina Célia Galvão Frem

Keyword(s):

Metal Organic Frameworks ◽

Fast Response ◽

Nitro Compounds ◽

Two Dimensional ◽

Metal Organic ◽

Luminescent Sensing

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Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding

10.26434/chemrxiv.10316681.v1 ◽

2019 ◽

Author(s):

Andrew Rosen ◽

M. Rasel Mian ◽

Timur Islamoglu ◽

Haoyuan Chen ◽

Omar Farha ◽

...

Keyword(s):

Density Functional ◽

Metal Organic Frameworks ◽

Redox Activity ◽

Screening Methods ◽

Bridging Ligands ◽

Metal Centers ◽

Computational Screening ◽

Open Metal Sites ◽

Metal Organic ◽

Unsaturated Metal Sites

Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O2 and N2 adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br-, μ-Cl-, μ-F-, μ-SH-, or μ-OH- groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O2 affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O2. In contrast with O2 adsorption, N2 adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V2+ open metal sites. As one example from the screening study, we predict that exchanging the μ-Cl- ligands of M2Cl2(BBTA) (H2BBTA = 1H,5H-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH- groups would significantly enhance the strength of O2 adsorption at the open metal sites without a corresponding increase in the N2 affinity. Experimental investigation of Co2Cl2(BBTA) and Co2(OH)2(BBTA) confirms that the former exhibits only weak physisorption, whereas the latter is capable of chemisorbing O2 at room temperature. The chemisorption behavior is attributed to the greater electron-donating character of the μ-OH- ligands and the presence of H-bonding interactions between the μ-OH- bridging ligands and the O2 adsorbate.

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