Regulating metal–organic frameworks as stationary phases and absorbents for analytical separations

2021 ◽  
Vol 13 (11) ◽  
pp. 1318-1331
Author(s):  
Sha-Sha Meng ◽  
Ming Xu ◽  
Ting Han ◽  
Yu-Hao Gu ◽  
Zhi-Yuan Gu
Keyword(s):  
Stationary Phases ◽  
Metal Organic Frameworks ◽  
Metal Centers ◽  
Analytical Separations ◽  
Metal Organic ◽  
Coordination Bonds

Metal–organic frameworks (MOFs) are highly ordered framework systems composed of metal centers and organic linkers formed through coordination bonds.

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

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

<p>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 O<sub>2</sub> and N<sub>2</sub> 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<sup>-</sup>, μ-Cl<sup>-</sup>, μ-F<sup>-</sup>, μ-SH<sup>-</sup>, or μ-OH<sup>-</sup> groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O<sub>2</sub> affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O<sub>2</sub>. In contrast with O<sub>2</sub> adsorption, N<sub>2</sub> adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V<sup>2+</sup> open metal sites. As one example from the screening study, we predict that exchanging the μ-Cl<sup>-</sup> ligands of M<sub>2</sub>Cl<sub>2</sub>(BBTA) (H<sub>2</sub>BBTA = 1<i>H</i>,5<i>H</i>-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH<sup>-</sup> groups would significantly enhance the strength of O<sub>2</sub> adsorption at the open metal sites without a corresponding increase in the N<sub>2</sub> affinity. Experimental investigation of Co<sub>2</sub>Cl<sub>2</sub>(BBTA) and Co<sub>2</sub>(OH)<sub>2</sub>(BBTA) confirms that the former exhibits only weak physisorption, whereas the latter is capable of chemisorbing O<sub>2</sub> at room temperature. The chemisorption behavior is attributed to the greater electron-donating character of the μ-OH<sup>-</sup><sub> </sub>ligands and the presence of H-bonding interactions between the μ-OH<sup>-</sup> bridging ligands and the O<sub>2</sub> adsorbate.</p>

Metal-organic frameworks for electrochemical reduction of carbon dioxide: The role of metal centers

2020 ◽  
Vol 40 ◽  
pp. 156-170 ◽  
Author(s):  
Ping Shao ◽  
Luocai Yi ◽  
Shumei Chen ◽  
Tianhua Zhou ◽  
Jian Zhang
Keyword(s):  
Carbon Dioxide ◽  
Electrochemical Reduction ◽  
Metal Organic Frameworks ◽  
Metal Centers ◽  
Metal Organic

Vapor-assisted self-conversion of basic carbonates in metal–organic frameworks

Nanoscale ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 5069-5076
Author(s):  
Miaomiao Jia ◽  
Jingyi Su ◽  
Pengcheng Su ◽  
Wanbin Li
Keyword(s):  
Carbon Capture ◽  
Metal Organic Frameworks ◽  
Solvent Vapor ◽  
Metal Centers ◽  
Metal Organic ◽  
High Alkalinity

Basic carbonates with high alkalinity are incorporated into metal–organic frameworks by solvent vapor-assisted self-conversion of partial metal centers to improve carbon capture performance.

Metal-organic frameworks as stationary phases for chromatography and solid phase extraction: A review

2022 ◽  
Vol 455 ◽  
pp. 214364
Author(s):  
Anna A. Kotova ◽  
Didier Thiebaut ◽  
Jérôme Vial ◽  
Antoine Tissot ◽  
Christian Serre
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Stationary Phases ◽  
Metal Organic Frameworks ◽  
Phase Extraction ◽  
Metal Organic

Metal–organic frameworks as stationary phases for mixed-mode separation applications

2014 ◽  
Vol 50 (28) ◽  
pp. 3735 ◽  
Author(s):  
Chris S. Hawes ◽  
Yada Nolvachai ◽  
Chadin Kulsing ◽  
Gregory P. Knowles ◽  
Alan L. Chaffee ◽  
...  
Keyword(s):  
Mixed Mode ◽  
Stationary Phases ◽  
Metal Organic Frameworks ◽  
Mode Separation ◽  
Metal Organic

scholarly journals Increasing the Stability of Metal-Organic Frameworks

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mathieu Bosch ◽  
Muwei Zhang ◽  
Hong-Cai Zhou
Keyword(s):  
Metal Organic Frameworks ◽  
Luminescent Properties ◽  
Vacuum Treatment ◽  
Donor Ligands ◽  
Gas Sorption ◽  
Nitrogen Donor Ligands ◽  
Metal Centers ◽  
Ligand Interactions ◽  
Metal Organic ◽  
The Stability

Metal-organic frameworks (MOFs) are a new category of advanced porous materials undergoing study by many researchers for their vast variety of both novel structures and potentially useful properties arising from them. Their high porosities, tunable structures, and convenient process of introducing both customizable functional groups and unsaturated metal centers have afforded excellent gas sorption and separation ability, catalytic activity, luminescent properties, and more. However, the robustness and reactivity of a given framework are largely dependent on its metal-ligand interactions, where the metal-containing clusters are often vulnerable to ligand substitution by water or other nucleophiles, meaning that the frameworks may collapse upon exposure even to moist air. Other frameworks may collapse upon thermal or vacuum treatment or simply over time. This instability limits the practical uses of many MOFs. In order to further enhance the stability of the framework, many different approaches, such as the utilization of high-valence metal ions or nitrogen-donor ligands, were recently investigated. This review details the efforts of both our research group and others to synthesize MOFs possessing drastically increased chemical and thermal stability, in addition to exemplary performance for catalysis, gas sorption, and separation.

scholarly journals Screening for high-spin metal organic frameworks (MOFs): density functional theory study on DUT-8(M1,M2) (with Mi = V,…,Cu)

2016 ◽  
Vol 18 (11) ◽  
pp. 8075-8080 ◽  
Author(s):  
Sebastian Schwalbe ◽  
Kai Trepte ◽  
Gotthard Seifert ◽  
Jens Kortus
Keyword(s):  
Density Functional Theory ◽  
High Spin ◽  
First Principles ◽  
Density Functional ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Metal Centers ◽  
Metal Organic

We present a first principles study of low-spin (LS)/high-spin (HS) screening for 3d metal centers in the metal organic framework (MOF) DUT-8(Ni).

scholarly journals Fe/Ga-CFA-6 – metal organic frameworks featuring trivalent metal centers and the 4,4′-bipyrazolyl ligand

CrystEngComm ◽  
2015 ◽  
Vol 17 (2) ◽  
pp. 313-322 ◽  
Author(s):  
Sebastian Spirkl ◽  
Maciej Grzywa ◽  
Christoph S. Zehe ◽  
Jürgen Senker ◽  
Serhiy Demeshko ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Trivalent Metal ◽  
Metal Centers ◽  
Metal Organic

Two novel metal–organic frameworks Fe-/Ga-CFA-6 based on trivalent metal centers and 4,4′-bipyrazolate linkers are presented and characterized in this work.

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