Control of the Coordination Status of the Open Metal Sites in Metal–Organic Frameworks for High Performance Separation of Polar Compounds

Langmuir ◽  
2012 ◽  
Vol 28 (17) ◽  
pp. 6794-6802 ◽  
Author(s):  
Yan-Yan Fu ◽  
Cheng-Xiong Yang ◽  
Xiu-Ping Yan
2016 ◽  
Vol 52 (15) ◽  
pp. 3223-3226 ◽  
Author(s):  
Bing Liu ◽  
Shuo Yao ◽  
Chao Shi ◽  
Guanghua Li ◽  
Qisheng Huo ◽  
...  

Two novel PMOFs with a high density of OMSs and LBSs were assembled using the SBB strategy and exhibited a high performance for CO2 capture and separation towards CO2, C2H6 and C3H8 over CH4.


2019 ◽  
Author(s):  
Andrew Rosen ◽  
M. Rasel Mian ◽  
Timur Islamoglu ◽  
Haoyuan Chen ◽  
Omar Farha ◽  
...  

<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>


2021 ◽  
Author(s):  
Dae-Woon Lim ◽  
Hiroshi Kitagawa

Since the transition of energy platforms, the proton-conductive metal–organic frameworks (MOFs) exhibiting high performance have been extensively investigated with rational strategies for their potential application in solid-state electrolytes.


Author(s):  
Jian Xiong ◽  
Ailin Li ◽  
Ye Liu ◽  
Liming Wang ◽  
Xiaohong Qin ◽  
...  

Integrating metal-organic frameworks (MOFs) into flexible polymeric matrices can improve their practical processibility and enlarge industrial applications greatly. However, current methods suffer from the serious aggregation of MOFs, low MOF...


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2869 ◽  
Author(s):  
Iván Taima-Mancera ◽  
Priscilla Rocío-Bautista ◽  
Jorge Pasán ◽  
Juan Ayala ◽  
Catalina Ruiz-Pérez ◽  
...  

Four metal-organic frameworks (MOFs), specifically UiO-66, UiO-66-NH2, UiO-66-NO2, and MIL-53(Al), were synthesized, characterized, and used as sorbents in a dispersive micro-solid phase extraction (D-µSPE) method for the determination of nine pollutants of different nature, including drugs, phenols, polycyclic aromatic hydrocarbons, and personal care products in environmental waters. The D-µSPE method, using these MOFs as sorbents and in combination with high-performance liquid chromatography (HPLC) and diode-array detection (DAD), was optimized. The optimization study pointed out to UiO-66-NO2 as the best MOF to use in the multi-component determination. Furthermore, the utilization of isoreticular MOFs based on UiO-66 with the same topology but different functional groups, and MIL-53(Al) to compare with, allowed us for the first time to evaluate the influence of such functionalization of the ligand with regards to the efficiency of the D-µSPE-HPLC-DAD method. Optimum conditions included: 20 mg of UiO-66-NO2 MOF in 20 mL of the aqueous sample, 3 min of agitation by vortex and 5 min of centrifugation, followed by the use of only 500 µL of acetonitrile as desorption solvent (once the MOF containing analytes was separated), 5 min of vortex and 5 min of centrifugation. The validation of the D-µSPE-HPLC-DAD method showed limits of detection down to 1.5 ng·L−1, average relative recoveries of 107% for a spiked level of 1.50 µg·L−1, and inter-day precision values with relative standard deviations lower than 14%, for the group of pollutants considered.


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