High SF6 selectivities and capacities in isostructural metal-organic frameworks with proper pore sizes and highly dense 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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Engineering Porosity Through Defects in a Giant Pore Metal–Organic Framework

10.26434/chemrxiv.12847574.v1 ◽

2020 ◽

Author(s):

Adam Sapnik ◽

Duncan Johnstone ◽

Sean M. Collins ◽

Giorgio Divitini ◽

Alice Bumstead ◽

...

Keyword(s):

Distribution Function ◽

Ball Milling ◽

Local Structure ◽

Pair Distribution Function ◽

Function Analysis ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Defect Engineering ◽

Metal Organic ◽

Unsaturated Metal Sites

Defect engineering is a powerful tool that can be used to tailor the properties of metal–organic frameworks (MOFs). Here, we incorporate defects through ball milling to systematically vary the porosity of the giant pore MOF, MIL-100 (Fe). We show that milling leads to the breaking of metal–linker bonds, generating more coordinatively unsaturated metal sites, and ultimately causes amorphisation. Pair distribution function analysis shows the hierarchical local structure is partiallyretained, even in the amorphised material. We find that the solvent toluene stabilises the MIL-100 (Fe) framework against collapse and leads to a substantial rentention of porosity over the non-stabilised material.

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The nanoscaled metal-organic framework ICR-2 as a carrier of porphyrins for photodynamic therapy

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.275 ◽

2018 ◽

Vol 9 ◽

pp. 2960-2967 ◽

Cited By ~ 5

Author(s):

Jan Hynek ◽

Sebastian Jurík ◽

Martina Koncošová ◽

Jaroslav Zelenka ◽

Ivana Křížová ◽

...

Keyword(s):

Inorganic Chemistry ◽

Photodynamic Therapy ◽

Photophysical Properties ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Biological Applications ◽

Nanoparticle Surface ◽

Metal Organic ◽

Unsaturated Metal Sites ◽

First Time

Nanosized porphyrin-containing metal-organic frameworks (MOFs) attract considerable attention as solid-state photosensitizers for biological applications. In this study, we have for the first time synthesised and characterised phosphinate-based MOF nanoparticles, nanoICR-2 (Inorganic Chemistry Rez). We demonstrate that nanoICR-2 can be decorated with anionic 5,10,15,20-tetrakis(4-R-phosphinatophenyl)porphyrins (R = methyl, isopropyl, phenyl) by utilizing unsaturated metal sites on the nanoparticle surface. The use of these porphyrins allows for superior loading of the nanoparticles when compared with commonly used 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin. The nanoICR-2/porphyrin composites retain part of the free porphyrins photophysical properties, while the photodynamic efficacy is strongly affected by the R substituent at the porphyrin phosphinate groups. Thus, phosphinatophenylporphyrin with phenyl substituents has the strongest photodynamic efficacy due to the most efficient cellular uptake.

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Continuous Variation of Lattice Dimensions and Pore Sizes in Metal–Organic Frameworks

Journal of the American Chemical Society ◽

10.1021/jacs.9b13072 ◽

2020 ◽

Vol 142 (10) ◽

pp. 4732-4738 ◽

Cited By ~ 10

Author(s):

Shuai Yuan ◽

Lan Huang ◽

Zhehao Huang ◽

Di Sun ◽

Jun-Sheng Qin ◽

...

Keyword(s):

Metal Organic Frameworks ◽

Continuous Variation ◽

Pore Sizes ◽

Metal Organic

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Creating coordinatively unsaturated metal sites in metal-organic-frameworks as efficient electrocatalysts for the oxygen evolution reaction: Insights into the active centers

Nano Energy ◽

10.1016/j.nanoen.2017.09.055 ◽

2017 ◽

Vol 41 ◽

pp. 417-425 ◽

Cited By ~ 175

Author(s):

Li Tao ◽

Chun-Yu Lin ◽

Shuo Dou ◽

Shi Feng ◽

Dawei Chen ◽

...

Keyword(s):

Oxygen Evolution ◽

Oxygen Evolution Reaction ◽

Metal Organic Frameworks ◽

Active Centers ◽

Metal Organic ◽

Unsaturated Metal Sites

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New Model for Predicting Adsorption of Polar Molecules in Metal–Organic Frameworks with Unsaturated Metal Sites

The Journal of Physical Chemistry Letters ◽

10.1021/acs.jpclett.8b00967 ◽

2018 ◽

Vol 9 (12) ◽

pp. 3544-3553 ◽

Cited By ~ 17

Author(s):

Christopher Campbell ◽

José R. B. Gomes ◽

Michael Fischer ◽

Miguel Jorge

Keyword(s):

Metal Organic Frameworks ◽

Polar Molecules ◽

New Model ◽

Metal Organic ◽

Unsaturated Metal Sites

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Fabricating better metal-organic frameworks separators for Li–S batteries: Pore sizes effects inspired channel modification strategy

Energy Storage Materials ◽

10.1016/j.ensm.2019.10.018 ◽

2020 ◽

Vol 25 ◽

pp. 164-171 ◽

Cited By ~ 7

Author(s):

Zhi Chang ◽

Yu Qiao ◽

Jie Wang ◽

Han Deng ◽

Ping He ◽

...

Keyword(s):

Metal Organic Frameworks ◽

Pore Sizes ◽

Metal Organic

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Interpenetrated Double Pillared-Layer CoII MOFs with pcu Topology

Australian Journal of Chemistry ◽

10.1071/ch16438 ◽

2017 ◽

Vol 70 (5) ◽

pp. 461 ◽

Cited By ~ 3

Author(s):

In-Hyeok Park ◽

Yunji Kang ◽

Eunji Lee ◽

Anjana Chanthapally ◽

Shim Sung Lee ◽

...

Keyword(s):

Conformational Changes ◽

Layer Structure ◽

Metal Organic Frameworks ◽

Trans Conformation ◽

X Ray ◽

Pore Sizes ◽

X Ray Crystallography ◽

Metal Organic

Three double pillared-layer CoII metal–organic frameworks (MOFs) with a pcu topology of a long, conformationally flexible, dipyridyl spacer ligand, 1,4-bis[2-(4-pyridyl)ethenyl]benzene (bpeb), and aromatic dicarboxylates (1,4-benzenedicarboxylate (bdc), 2,6-naphthalenedicarboxylate (ndc), and biphenyl-4,4′-dicarboxylate (bpdc)) have been synthesised and structurally characterised by X-ray crystallography. The MOFs are denoted as [Co2(bpeb)2(bdc)2]·DMF·3H2O (1), [Co2(bpeb)2(ndc)2]·1.75DMF·3.75H2O (2), and [Co2(bpeb)2(bpdc)2]·3.5DMF·4H2O (3). In the dinuclear repeating unit, four carboxylates are bonded to two CoII atoms forming a (4,4) layer structure. The axial positions are occupied by bpeb ligands. Of these, 1 and 2 have 2-fold interpenetration, whereas 3 displays 3-fold interpenetration. The two bpeb space ligands in 1 have trans,trans,trans and trans,cis,trans conformations. In contrast, the bpeb ligands in 2 and 3 have a trans,cis,trans conformation. Although the olefin groups in two adjacent bpeb ligands, as the double pillars in 2 and 3, satisfy the conditions for photo-dimerisation to occur, they are photo-inactive. The conformational changes of bpeb, bonding modes of the dicarboxylates, and pore sizes in these double pillared-layer compounds have been discussed.

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Elucidating Gating Effects for Hydrogen Sorption in MFU-4-Type Triazolate-Based Metal-Organic Frameworks Featuring Different Pore Sizes

Chemistry - A European Journal ◽

10.1002/chem.201001872 ◽

2011 ◽

Vol 17 (6) ◽

pp. 1837-1848 ◽

Cited By ~ 150

Author(s):

Dmytro Denysenko ◽

Maciej Grzywa ◽

Markus Tonigold ◽

Barbara Streppel ◽

Ivana Krkljus ◽

...

Keyword(s):

Metal Organic Frameworks ◽

Hydrogen Sorption ◽

Pore Sizes ◽

Metal Organic

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Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding: Design Rules and Ambient Temperature O2 Chemisorption in a Cobalt−Triazolate Framework

10.26434/chemrxiv.10316681.v2 ◽

2020 ◽

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 predicted 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 weak physisorption of both N2 and O2, whereas the latter is capable of chemisorbing O2 at room temperature in a highly selective manner. The O2 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 reduced O2 adsorbate.

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