scholarly journals 3D Metal–Organic Frameworks Based on Co(II) and Bithiophendicarboxylate: Synthesis, Crystal Structures, Gas Adsorption, and Magnetic Properties

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1269
Author(s):  
Vadim A. Dubskikh ◽  
Anna A. Lysova ◽  
Denis G. Samsonenko ◽  
Alexander N. Lavrov ◽  
Konstantin A. Kovalenko ◽  
...  

Three new 3D metal-organic porous frameworks based on Co(II) and 2,2′-bithiophen-5,5′-dicarboxylate (btdc2−) [Co3(btdc)3(bpy)2]·4DMF, 1; [Co3(btdc)3(pz)(dmf)2]·4DMF·1.5H2O, 2; [Co3(btdc)3(dmf)4]∙2DMF∙2H2O, 3 (bpy = 2,2′-bipyridyl, pz = pyrazine, dmf = N,N-dimethylformamide) were synthesized and structurally characterized. All compounds share the same trinuclear carboxylate building units {Co3(RCOO)6}, connected either by btdc2– ligands (1, 3) or by both btdc2– and pz bridging ligands (2). The permanent porosity of 1 was confirmed by N2, O2, CO, CO2, CH4 adsorption measurements at various temperatures (77 K, 273 K, 298 K), resulted in BET surface area 667 m2⋅g−1 and promising gas separation performance with selectivity factors up to 35.7 for CO2/N2, 45.4 for CO2/O2, 20.8 for CO2/CO, and 4.8 for CO2/CH4. The molar magnetic susceptibilities χp(T) were measured for 1 and 2 in the temperature range 1.77–330 K at magnetic fields up to 10 kOe. The room-temperature values of the effective magnetic moments for compounds 1 and 2 are μeff (300 K) ≈ 4.93 μB. The obtained results confirm the mainly paramagnetic nature of both compounds with some antiferromagnetic interactions at low-temperatures T < 20 K in 2 between the Co(II) cations separated by short pz linkers. Similar conclusions were also derived from the field-depending magnetization data of 1 and 2.

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1421 ◽  
Author(s):  
Baosheng Ge ◽  
Yanyan Xu ◽  
Haoru Zhao ◽  
Haixiang Sun ◽  
Yaoli Guo ◽  
...  

Mixed matrix membranes (MMMs) attract great attention due to their outstanding gas separation performance. The compatibility between the fillers and the polymer matrix is one of the key points for the preparation of high-performance MMMs. In this work, MMMs consisting of metal-organic frameworks (MOFs) of amine-modified Cu-BTC (NH2-Cu-BTC; BTC = 1,3,5-benzenetricarboxylic acid) and submicrometer-sized amine-modified Cu-BTC (sub-NH2-Cu-BTC) incorporated into a Pebax-1657 polymer were fabricated for the gas separation. The SEM image and Fourier transform infrared spectroscopy (FTIR) spectra showed an increase in the surface roughness of MOFs and the presence of amino groups on the surface of Cu-BTC after the amination modification, and a decrease in the size of MOFs crystals after the submicrometer-sized aminated modification. Gas adsorption analysis indicated that NH2-Cu-BTC and sub-NH2-Cu-BTC had a higher gas adsorption capacity for CO2 compared to the unmodified Cu-BTC. The scanning electron microscopy (SEM) image showed that NH2-Cu-BTC and sub-NH2-Cu-BTC, especially sub-NH2-Cu-BTC, had a better compatibility with a polyether-block-amide (Pebax) matrix in the MMMs. The gas separation performance indicated that the Pebax/sub-NH2-Cu-BTC MMMs evidently improved the CO2/N2 and CO2/CH4 selectivity at the expense of a slight CO2 permeability. The results reveal that modified MOF-filled MMMs possess great potential for applications in the CO2 separation field.


2018 ◽  
Author(s):  
Huong T. D. Nguyen ◽  
Y B. N. Tran ◽  
Hung N. Nguyen ◽  
Tranh C. Nguyen ◽  
Felipe Gándara ◽  
...  

<p>Three novel lanthanide metal˗organic frameworks (Ln-MOFs), namely MOF-590, -591, and -592 were constructed from a naphthalene diimide tetracarboxylic acid. Gas adsorption measurements of MOF-591 and -592 revealed good adsorption of CO<sub>2</sub> (low pressure, at room temperature) and moderate CO<sub>2</sub> selectivity over N<sub>2</sub> and CH<sub>4</sub>. Accordingly, breakthrough measurements were performed on a representative MOF-592, in which the separation of CO<sub>2</sub> from binary mixture containing N<sub>2</sub> and CO<sub>2</sub> was demonstrated without any loss in performance over three consecutive cycles. Moreover, MOF-590, MOF-591, and MOF-592 exhibited catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO<sub>2</sub> under mild conditions (1 atm CO<sub>2</sub>, 80 °C, and solvent-free). Among the new materials, MOF-590 revealed a remarkable efficiency with exceptional conversion (96%), selectivity (95%), and yield (91%). </p><br>


The Analyst ◽  
2019 ◽  
Vol 144 (16) ◽  
pp. 4887-4896 ◽  
Author(s):  
Mariyemu Tuergong ◽  
Patima Nizamidin ◽  
Abliz Yimit ◽  
Rena Simayi

The optical gas adsorption behaviors of [Zn2(bdc)2(dpNDI)]n membranes were studied for the first time. Under UV light irradiation, they exhibited a greater adsorption response to xylene gas with adsorption capacity of 6.46 μg cm−2 per unit surface.


2018 ◽  
Author(s):  
Huong T. D. Nguyen ◽  
Y B. N. Tran ◽  
Hung N. Nguyen ◽  
Tranh C. Nguyen ◽  
Felipe Gándara ◽  
...  

<p>Three novel lanthanide metal˗organic frameworks (Ln-MOFs), namely MOF-590, -591, and -592 were constructed from a naphthalene diimide tetracarboxylic acid. Gas adsorption measurements of MOF-591 and -592 revealed good adsorption of CO<sub>2</sub> (low pressure, at room temperature) and moderate CO<sub>2</sub> selectivity over N<sub>2</sub> and CH<sub>4</sub>. Accordingly, breakthrough measurements were performed on a representative MOF-592, in which the separation of CO<sub>2</sub> from binary mixture containing N<sub>2</sub> and CO<sub>2</sub> was demonstrated without any loss in performance over three consecutive cycles. Moreover, MOF-590, MOF-591, and MOF-592 exhibited catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO<sub>2</sub> under mild conditions (1 atm CO<sub>2</sub>, 80 °C, and solvent-free). Among the new materials, MOF-590 revealed a remarkable efficiency with exceptional conversion (96%), selectivity (95%), and yield (91%). </p><br>


2018 ◽  
Vol 42 (14) ◽  
pp. 12013-12023 ◽  
Author(s):  
Elahe Ahmadi Feijani ◽  
Hossein Mahdavi ◽  
Ahmad Tavassoli

A CuBTC (copper(ii) benzene-1,3,5-tricarboxylate) metal organic framework (MOF) and graphene oxide (GO) nanosheets were introduced into a semi-crystalline PVDF to produce mixed matrix membranes (MMMs) to promote gas separation performance.


Author(s):  
Ying-Pin Chen ◽  
Tian-Fu Liu ◽  
Stephen Fordham ◽  
Hong-Cai Zhou

Two metal–organic frameworks [PCN-426(Ni) and PCN-427(Cu)] have been designed and synthesized to investigate the structure predictability using a SBB (supermolecular building blocks) approach. Tetratopic ligands featuring 120° angular carboxylate moieties were coordinated with a [Ni3(μ3-O)] cluster and a [Cu2O2] unit, respectively. As topologically predicted, 4-connected networks with square coordination adopted the nbo net for the Ni-MOF and ssb net for the Cu-MOF. PCN-426(Ni) was augmented with 12-connected octahedral SBBs, while PCN-427(Cu) was constructed with tetragonal open channels. After a CO2 supercritical drying procedure, the PCN-426(Ni) possessed a Brunauer–Emmett–Teller (BET) surface area as high as 3935 m2 g−1 and impressively high N2 uptake of 1500 cm3 g−1. This work demonstrates the generalization of the SBB strategy, finding an alternative to inconvenient synthetic processes to achieve the desired structural features.


2021 ◽  
Author(s):  
Kourosh Esfandiari ◽  
Ali Asghar Ghoreyshi

Abstract In this research, composites of a well-known metal-organic framework, CuBTC, and activated carbon (AC) are synthesized through solvothermal method and their performance is evaluated from viewpoint of CO2/H2 separation. For this purpose, different amounts of functionalized AC are incorporated in CuBTC structure and a volumetric-chromatographic technique is employed to measure the selectivity of CO2 over H2. XRD patterns, BET surface area, and FESEM images are employed to determine textural properties of as-synthesized samples. It is demonstrated that, while crystalline structure of CuBTC is not affected by incorporation of AC particles, adding proper amounts of functionalized AC to CuBTC matrix can cause higher CO2/H2 separation factor at low pressure and 298 K. Obtained results suggest that adding 0.050 g AC to CuBTC can increase the CO2/H2 selectivity up to around 32 which is double the separation factor of bare CuBTC (i.e. ≈ 15). Enhanced hydrogen separation behavior might be attributed to the presence of carbonyl and nitrile functional groups exhibiting CO2 adsorption affinity on the surface of AC added to the optimum CuBTC structure.


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