An Ultrastable Metal Azolate Framework with Binding Pockets for Optimal Carbon Dioxide Capture

Abstract

In the evolution of metal-organic frameworks (MOFs) for carbon capture,alasting challenge is to strike ab alance between high uptake capacity/selectivity and low energy cost for regeneration. Meanwhile,t hese man-made materials have to survive from practical demands such as stability under harsh conditions and feasibility of scale-up synthesis.R eported here is an ew MOF,Z n(imPim) (aka. MAF-stu-1), with an imidazoled erivative ligand, featuring binding pockets that can accommodate CO 2 molecules in afitlike-a-glovemanner.Suchahigh degree of shape complementarity allows direct observation of the loaded CO 2 in the pockets,and warrants its optimal carbon capture performances exceeding the best-performing MOFs nowadays.Coupled with the recordthermal (up to 680 8 8C) and chemical stability,aswell as rapid large-scale production, both encoded in the material design, Zn(imPim) represents amost competitive candidate to tackle the immediate problems of carbon dioxide capture.

Pyrazine‐interior‐embodied MOF‐74 for selective CO2 adsorption

“…For example, the adsorption selectivity at 100 kPa and 298 K follows the order py‐MOF‐74c (471) > py‐MOF‐74b (147) > py‐MOF‐74a (87) > MOF‐74 (49). In brief, the competitive adsorption potential of py‐MOF‐74c for CO 2 over N 2 is greatly superior to previously reported MOFs under similar conditions, such as NJFU‐2a (195), 40 Zn(imPim) (106), 30 and BTU‐11 (43) 41 . These results indicate that py‐MOF‐74 displays exceptionally selectivity for CO 2 adsorption, which makes it a good candidate for MOF membrane materials and nanofillers of mixed matrix membranes that are employed in dynamic CO 2 separation.…”

Harnessing Shape Complementarity for Upgraded Cyclohexane Purification through Adaptive Bottlenecked Pores in an Imidazole‐Containing MOF

“…In contrast, the CH inclusion phase cannot be obtained. Interestingly, the Bz guests not only reside in the pores in pair but also fit well with the neck segments; the Connolly surface view (Figure 3 a), [29, 41] which is commonly used for delineating the shape of solvent accessible regions at protein‐protein interfaces, showcases high‐degree host‐guest shape complementarity in the bottlenecked pores of MAF‐stu‐13. Moreover, the host framework shows slight distortion after Bz guest inclusion.…”

“…Our solution to the optimal Bz/CH separation problem arose out of inspection of the overall pore shape of a new imidazole‐containing MOF, [24–30] namely Zn(MIBA) 2 (also called MAF‐stu‐13, HMIBA=4‐(1 H ‐2‐methyl‐imidazol‐1‐yl)benzoic acid), which was synthesized by solvothermal reaction and can be scaled‐up to obtain gram‐scale samples with a high yield (86 %) in 1 hour (Supporting Information, Experimental Details) [31, 32] . MAF‐stu‐13 crystallized in tetragonal P 4 nc space group, in which a tetrahedral Zn II ion is coordinated to two imidazolyl‐N and two carboxyl‐O sites from the deprotonated MIBA ligand (Supporting Information, Tables S1, S2 and Figure S1).…”

“…It should be noted extremely high uptakes (>800 g L −1 ) were reported for a few MOFs; [12, 13, 15] however, they did not display effective liquid‐phase Bz/CH selectivity. In terms of the general problem concerning the trade‐off between uptake and selectivity in various separations, [29] MAF‐stu‐13 outperforms all others featuring a high liquid separation selectivity of 412 along with high Bz uptake (Figure 4 f). In particular, the ultrahigh product purity (99.4 %) strengthens its advantage in practical application; other candidate materials include: hybrid[3]arene (97.5 %), [19] T[5]‐(OMe) 5 (92.3 %), [18] [Li 2 Zn 2 (NO 2 ‐bdc) 3 (bpy)] (95 %) [16] and [Zn 4 (EGO 2 ) 2 (tdc) 2 (dabco)] (selectivity 92) [14] …”

Room-Temperature Stable Noncovalent Charge-Transfer Dianion Biradical to Produce Singlet Oxygen by Visible or Near-Infrared Light Photoexcitation

“…Photofunctional organic molecules have attracted extensive attention due to their widespread application in photodynamic therapy (PDT), , fluorescence bioimaging, − organic light-emitting diodes (OLEDs), − and photocatalysis. − Since the electronic absorption of small unconjugated organic molecules generally locates in the ultraviolet region, their application in the visible range is greatly restricted. − To expand the applicability of organic functional materials in the visible and near-infrared (NIR) range, the formation of metal–ligand complexes, the existence of supermolecules, and the construction of large π structural systems (Scheme ) are efficacious ways to make their absorption bathochromic shift, − but there exist obvious drawbacks including complicated design, tedious synthesis, use of transition metals, and high cost. Although intramolecular donor–acceptor (D–A) architecture can dramatically tune the photophysical and electrochemical properties due to the intramolecular charge transfer (CT), furnishing an alternative way to red-shift their electronic absorption spectra, − intermolecular D–A systems and their application are rarely reported.…”