A Highly Robust and Conducting Ultramicroporous 3D Fe(II)-Based Metal-Organic Framework for Efficient Energy Storage.

Exploitation of metal-organic framework (MOF) materials as active electrodes for energy storage or conversion is reasonably challenging owing to their poor robustness against various acidic/basic conditions and conventionally low electric conductivity. Keeping this in perspective, herein, a 3D ultramicroporous triazolate Fe-MOF (abbreviated as Fe-MET) is judiciously employed using cheap and commercially available starting materials. Fe-MET possesses ultra-stability against various chemical environments (pH-1 to pH-14 with varied organic solvents) and is highly electrically conductive (σ = 0.19 S m-1) in one fell swoop. By taking advantage of the properties mentioned above, Fe-MET electrodes give prominence to electrochemical capacitor (EC) performance by delivering an astounding gravimetric (304 F g-1) and areal (181 mF cm-2) capacitance at 0.5 A g-1 current density with exceptionally high cycling stability. Implementation of Fe-MET as an exclusive (by not using any conductive additives) EC electrode in solid-state energy storage devices outperforms most of the reported MOF-based EC materials and even surpasses certain porous carbon and graphene materials, showcasing superior capabilities and great promise compared to various other alternatives as energy storage materials.

Mechanistical Insights into the Ultrasensitive Detection of Radioactive and Chemotoxic UO22+ Ions by a Porous Anionic Co-Metal-Organic Framework.

Development of a simple, cost-efficient, and portable UO22+ sensory probe with high selectivity and sensitivity is highly desirable in the context of monitoring radioactive contaminants. Herein, we report a luminescent Co-based metal-organic framework (MOF), {[Me2NH2]0.5[Co(DATRz)0.5(NH2BDC)]·xG}n (1), equipped with abundant amino functionalities for the selective detection of uranyl cations. The ionic structure consists of two types of channels decorated with plentiful Lewis basic amino moieties, which trigger a stronger acid-base interaction with the diffused cationic units and thus can selectively quench the fluorescence intensity in the presence of other interfering ions. Furthermore, the limit of detection for selective UO22+ sensing was achieved to be as low as 0.13 µM (30.94 ppb) with rapid responsiveness and multiple recyclabilities, demonstrating its excellent efficacy. Density functional theory (DFT) calculations further unraveled the preferred binding sites of the UO22+ ions in the tubular channel of the MOF structure. Orbital hybridization between NH2BDC/DATRz and UO22+ together with its significantly large electron-accepting ability is identified as responsible for the luminescence quenching. More importantly, the prepared 1@PVDF {poly(vinylidene difluoride)} mixed-matrix membrane (MMM) displayed good fluorescence activity comparable to 1, which is of great significance for their practical employment as MOF-based luminosensors in real-world sensing application.

A Water-Stable Cationic SIFSIX MOF for Luminescent Probing of Cr2 O7 2- via Single-Crystal to Single-Crystal Transformation.

The sensing and monitoring of toxic oxo-anion contaminants in water are of significant importance to biological and environmental systems. A rare hydro-stable SIFSIX metal-organic framework, SiF6 @MOF-1, {[Cu(L)2 (H2 O)2 ]·(SiF6 )(H2 O)}n , with exchangeable SiF6 2- anion in its pore is strategically designed and synthesized, exhibiting selective detection of toxic Cr2 O7 2- oxo-anion in an aqueous medium having high sensitivity, selectivity, and recyclability through fluorescence quenching phenomena. More importantly, the recognition and ion exchange mechanism is unveiled through the rarely explored single-crystal-to-single crystal (SC-SC) fashion with well-resolved structures. A thorough SC-SC study with interfering anions (Cl- , F- , I- , NO3 - , HCO3 - , SO4 2- , SCN- , IO3 - ) revealed no such transformations to take place, as per line with quenching studies. Density functional theory calculations revealed that despite a lesser binding affinity, Cr2 O7 2- shows strong orbital mixing and large driving forces for electron transfer than SiF6 2- , and thus enlightens the fluorescence quenching mechanism. This work inaugurates the usage of a SIFSIX MOF toward sensing application domain under aqueous medium where hydrolytic stability is a prime concern for their plausible implementation as sensor materials.

Highly Robust Metal-Organic Framework for Efficiently Catalyzing Knoevenagel Condensation and the Strecker Reaction under Solvent-Free Conditions.

Metal-organic frameworks (MOFs) have been recognized as one of the most promising porous materials and offer great opportunities for the rational design of new catalytic solids having great structural diversity and functional tunability. Despite numerous inherent merits, their chemical environment instability limits their practical usage and demands further exploration. Herein, by employing the mixed-ligand approach, we have designed and developed a robust 3D Co-MOF, [Co2(µ2-O)(TDC)2(L)(H2O)2]·2DMF (H2TDC = 2,5-thiophenedicarboxylic acid, L = 3,3'-azobispyridine), IITKGP-50 (IITKGP stands for the Indian Institute of Technology Kharagpur), which exhibited excellent framework robustness not only in water but also in a wide range of aqueous pH solutions (pH = 2-12). Taking advantage of superior framework robustness and the presence of high-density open metal sites, IITKGP-50 was further explored in catalyzing the two-component Knoevenagel condensation reaction and three-component Strecker reactions. Moreover, to verify the size selectivity of IITKGP-50, smaller to bulkier substrates in comparison with the MOF's pore cavity (8.1 × 5.6 Å2) were employed, in which relatively lesser conversions for the sterically bulkier aldehyde derivatives confirmed that the catalytic cycle occurs inside the pore cavity. The easy scalability, lower catalyst loading compared to that of benchmark MOFs, magnificent conversion rate over a wide range of substrates, and excellent recyclability without significant performance loss made IITKGP-50 a promising heterogeneous catalyst candidate.

Dynamic Hydrogen-Bonded Zinc Adeninate Framework (ZAF) for Immobilization of Catalytic DNA.

Effective immobilization and delivery of genetic materials is at the forefront of biological and medical research directed toward tackling scientific challenges such as gene therapy and cancer treatment. Herein we present a biologically inspired hydrogen-bonded zinc adeninate framework (ZAF) consisting of zinc adeninate macrocycles that self-assemble into a 3D framework through adenine-adenine interactions. ZAF can efficiently immobilize DNAzyme with full protection against enzyme degradation and physiological conditions until it is successfully delivered into the nucleus. As compared to zeolitic imidazolate frameworks (ZIFs), ZAFs are twofold more biocompatible with a significant loading efficiency of 96 %. Overall, our design paves the way for expanding functional hydrogen-bonding-based systems as potential platforms for the loading and delivery of biologics.

Adsorptive Molecular Sieving of Styrene over Ethylbenzene by Trianglimine Crystals.

The separation of styrene (ST) and ethylbenzene (EB) mixtures is of great importance in the petrochemical and plastics industries. Current technology employs multiple cycles of energy-intensive distillation due to the very close boiling points of ST and EB. Here, we show that the molecular sieving properties of easily scalable and stable trianglimine crystals offer ultrahigh selectivity (99%) for styrene separation. The unique molecular sieving properties of trianglimine crystals are corroborated by DFT calculations, suggesting that the incorporation of the nonplanar EB requires a significant deformation of the macrocyclic cavity whereas the planar ST can be easily accommodated in the cavity.

Porous Anionic Co(II) Metal-Organic Framework, with a High Density of Amino Groups, as a Superior Luminescent Sensor for Turn-on Al(III) Detection.

Accumulation of high concentrations of Al(III) in body has a direct impact on health and therefore, the trace detection of Al(III) has been a matter for substantial concern. An anionic metal organic framework ({[Me2 NH2 ]0.5 [Co(DATRz)0.5 (NH2 BDC)] ⋅ xG}n ; 1; HDATRz=3,5-diamino-1,2,4-triazole, H2 NH2 -BDC=2-amino-1,4-benzenedicarboxylic acid, G=guest molecule) composed of two types of secondary building units (SBU) and channels of varying sizes was synthesized by employing a rational design mixed ligand synthesis approach. Free -NH2 groups on both the ligands are immobilized onto the pore surface of the MOF which acts as a superior luminescent sensor for turn-on Al(III) detection. Furthermore, the large channels could allow the counter-ions to pass through and get exchanged to selectively detect Al(III) in presence of other seventeen metal ions with magnificent luminescence enhancement. The observed limit of detection is as low as 17.5 ppb, which is the lowest among the MOF-based sensors achieved so far. To make this detection approach simple, portable and economic, we demonstrate MOF filter paper test for real time naked eye observation.

From Capsule to Helix: Guest-Induced Superstructures of Chiral Macrocycle Crystals.

Predicting, controlling, understanding, and elucidating the phase transition from gel to crystal are highly important for the development of various functional materials with macroscopic properties. Here, we show a detailed and systematic description of the self-assembly process of an enantiopure trianglimine macrocyclic host from gel to single crystals. This proceeds via an unprecedented formation of capsule-like or right-handed helix superstructures as metastable products, depending on the nature of the guest molecule. Mesitylene promotes the formation of capsule-like superstructures, whereas toluene results in the formation of helices as intermediates during the course of crystallization. Single-crystal results demonstrate that the crystals obtained via the direct self-assembly from the gel phase are different from the crystals obtained from the stepwise assembly of the intermediate superstructures. Hence, investigating the phase-transition superstructures that self-assemble through the process of crystallization can unravel new molecular ordering with unexplored host-guest interactions. Such understanding will provide further tools to control hierarchical assemblies at the molecular level and consequently design or dictate the properties of evolved materials.

A Phosphate-Based Silver-Bipyridine 1D Coordination Polymer with Crystallized Phosphoric Acid as Superprotonic Conductor.

Phosphate-based silver-bipyridine (Ag-bpy) 1D coordination polymer {[{Ag(4,4'-bpy)}2 {Ag(4,4'-bpy)(H2 PO4 )}]⋅2 H2 PO4 ⋅H3 PO4 ⋅5 H2 O}n (1) with free phosphoric acid (H3 PO4 ), its conjugate base (H2 PO4 - ) and water molecules in its lattice was synthesized by room-temperature crystallization and the hydrothermal method. An XRD study showed that coordinated H2 PO4 - , lattice H2 PO4 - anions, free H3 PO4 and lattice water molecules are interconnected by H-bonding interactions, forming an infinitely extended 2D H-bonded network that facilitates proton transfer. This material exhibits a high proton conductivity of 3.3×10-3  S cm-1 at 80 °C and 95 % relative humidity (RH). Furthermore, synthesis of this material from commercially available starting materials in water can be easily scaled up, and it is highly stable under extreme conditions of conductivity measurements. This report inaugurates the usage and design principle of proton-conducting frameworks based on crystallized phosphoric acid and phosphate.

A "Thermodynamically Stable" 2D Nickel Metal-Organic Framework over a Wide pH Range with Scalable Preparation for Efficient C2 s over C1 Hydrocarbon Separations.

The design and construction of "thermodynamically stable" metal-organic frameworks (MOFs) that can survive in liquid water, boiling water, and acidic/basic solutions over a wide pH range is highly desirable for many practical applications, especially adsorption-based gas separations with obvious scalable preparations. Herein, a new thermodynamically stable Ni MOF, {[Ni(L)(1,4-NDC)(H2 O)2 ]}n (IITKGP-20; L=4,4'-azobispyridine; 1,4-NDC=1,4-naphthalene dicarboxylic acid; IITKGP stands for the Indian Institute of Technology Kharagpur), has been designed that displays moderate porosity with a BET surface area of 218 m2 g-1 and micropores along the [10-1] direction. As an alternative to a cost-intensive, cryogenic, high-pressure distillation process for the separation of hydrocarbons, MOFs have recently shown promise for such separations. Thus, towards an application standpoint, this MOF exhibits a higher uptake of C2 hydrocarbons over that of C1 hydrocarbon under ambient conditions, with one of the highest selectivities based on the ideal adsorbed solution theory (IAST) method. A combination of two strategies (the presence of stronger metal-N coordination of the spacer and the hydrophobicity of the aromatic moiety of the organic ligand) possibly makes the framework highly robust, even stable in boiling water and over a wide range of pH 2-10, and represents the first example of a thermodynamically stable MOF displaying a 2D structural network. Moreover, this material is easily scalable by heating the reaction mixture at reflux overnight. Because such separations are performed in the presence of water vapor and acidic gases, there is a great need to explore thermodynamically stable MOFs that retain not only structural integrity, but also the porosity of the frameworks.

Two Closely Related Zn(II)-MOFs for Their Large Difference in CO2 Uptake Capacities and Selective CO2 Sorption.

Two azo functionalized Zn(II)-based MOFs, {[Zn(SDB)(3,3'-L)0.5]·xG}n, IITKGP-13A, and {[Zn2(SDB)2(4,4'-L)]·xG}n, IITKGP-13B (IITKGP stands for Indian Institute of Technology Kharagpur), have been constructed through the self-assembly of isomeric N,N'-donor spacers (3,3'-L = 3,3'-azobispyridine and 4,4'-L = 4,4'-azobispyridine) with organic ligand 4,4'-sulfonyldibenzoic acid (SDBH2) and Zn(NO3)2·6H2O (G represents disordered solvent molecules). Single-crystal X-ray diffraction studies reveal the 2D structure with sql topology for both MOFs. However, the subtle change in positions of coordinating N atoms of spacers makes IITKGP-13A noninterpenetrated, while IITKGP-13B bears a 2-fold interpenetrated structure. IITKGP-13A exhibits higher uptake of CO2 over CH4 and N2 with high IAST selectivities for mixed CO2/CH4 (50:50, biogas) and CO2/N2 (15:85, flue gas) gas systems. In contrast, IITKGP-13B takes up very low amount of CO2 gas (0.4 mmol g-1) compared to IITKGP-13A (1.65 mmol g-1) at 295 K. Density functional theory (DFT)-based electronic structure calculations have been performed to explain the origin of the large differences in CO2 uptake capacity between the two MOFs at the atomistic level. The results show that the value of the change in enthalpy (ΔH) at 298 K temperature and 1 bar pressure for the CO2 adsorption is more negative in IITKGP-13A as compared to that in IITKGP-13B, thus indicating that CO2 molecules are more favored to get adsorbed in IITKGP-13A than in IITKGP-13B. The computed values for the Gibbs' free energy change (ΔG) for the CO2 adsorption are positive for both of the MOFs, but a higher value is observed for the IITKGP-13B. The noncovalent types of interactions are the main contribution toward the attractive energies between the host MOF frameworks and guest CO2 molecules, which has been studied with the help of energy decomposition analysis (EDA).

Metal-Organic Frameworks and Other Crystalline Materials for Ultrahigh Superprotonic Conductivities of 10-2 †S cm-1 or Higher.

Proton-conducting materials in the solid state have received immense attention for their role as electrolytes in proton-exchange membrane fuel cells. Recently, crystalline materials-metal-organic frameworks (MOFs), hydrogen-bonded organic frameworks (HOFs), covalent organic frameworks (COFs), polyoxometalates (POMs), and porous organic crystals-have become an exciting research topic in the field of proton-conducting materials. For a better electrolyte, a high proton conductivity on the order of 10-2  S cm-1 or higher is preferred as efficient proton transport between the electrodes is ultimately necessary. With an emphasis on design principles, this Concept will focus on MOFs and other crystalline solid-based proton-conducting platforms that exhibit "ultrahigh superprotonic" conductivities with values in excess of 10-2  S cm-1 . While only a handful of MOFs exhibit such an ultrahigh conductivity, this quality in other systems is even rarer. In addition to interpreting the structural-functional correlation by taking advantage of their crystalline nature, we address the challenges and promising directions for future research.

Metalo Hydrogen-Bonded Organic Frameworks (MHOFs) as New Class of Crystalline Materials for Protonic Conduction.

Recently, proton conduction has been a thread of high potential owing to its wide applications in fuel-cell technology. In the search for a new class of crystalline materials for protonic conductors, three metalo hydrogen-bonded organic frameworks (MHOFs) based on [Ni(Imdz)6 ]2+ and arene disulfonates (MHOF1 and MHOF2) or dicarboxylate (MHOF3) have been reported (Imdz=imidazole). The presence of an ionic backbone with charge-assisted H-bonds, coupled with amphiprotic imidazoles made these MHOFs protonic conductors, exhibiting conduction values of 0.75×10-3 , 3.5×10-4 and 0.97×10-3  S cm-1 , respectively, at 80 °C and 98 % relative humidity, which are comparable to other crystalline metal-organic framework, coordination polymer, polyoxometalate, covalent organic framework, and hydrogen-bonded organic framework materials. This report initiates the usage of MHOF materials as a new class of solid-state proton conductors.

How To Achieve High Regioselectivity in Barrier-less Nucleophilic Addition to p-Benzynes Generated via Bergman Cyclization of Unsymmetrical Cyclic Azaenediyne?

Inducing high regioselectivity in nucleophilic addition to p-benzynes, first reported by Perrin and O'Connor et al. ( J. Am. Chem. Soc. 2007 , 129 , 4795 - 4799 ) has been a challenge as the reaction involves a very fast barrier-less addition of nucleophile. On the other hand, achieving a high degree of regioselectivity is important as that will make the reaction synthetically useful. Recently, a study has been reported from our group ( J. Org. Chem. 2018 , 83 , 7730 - 7740 ), whereby it was shown that nucleophilic addition to p-benzynes derived from unsymmetrical N-substituted cyclic enediynes proceeds with low extent of selectivity by incorporation of groups with divergent electronic characters. Herein, we report that excellent regioselectivity (>99%) can be achieved keeping an ortho alkoxy group in unsymmetrical 1,2-dialkynylbenzene in the form of a cyclic enediyne in quantitative yields. High regioselectivity (∼84%) is also shown by pyridine based enediynes where the pyridine nitrogen is in a 1,3-relationship with the impending radical center, expanding the synthetic scope of this nucleophilic addition. The regioselectivity can be explained in terms of computed electrostatic potentials which are substantially different around two radical centers arising due to the "ortho effect" (conformational alignment of lone pair of the ortho alkoxy oxygen or the nitrogen in pyridine systems).

A Microporous Co-MOF for Highly Selective CO2 Sorption in High Loadings Involving Aryl C-H···O═C═O Interactions: Combined Simulation and Breakthrough Studies.

In the context of porous crystalline materials toward CO2 separation and capture, a new 2-fold interpenetrated 3D microporous Co-MOF, IITKGP-11 (IITKGP denotes Indian Institute of Technology Kharagpur), has been synthesized consisting of a 1D channel of ∼3.6 × 5.0 Å2 along the [101] direction with a cavity volume of 35.20%. This microporous framework with a BET surface area of 253 m2g-1 shows higher uptake of CO2 (under 1 bar, 3.35 and 2.70 mmol g-1 at 273 and 295 K, respectively), with high separation selectivities for CO2/N2 and CO2/CH4 gas mixtures under ambient conditions as estimated through IAST calculation. Moreover, real time dynamic breakthrough studies reveal the high adsorption selectivity toward CO2 for these binary mixed gases at 295 K and 1 bar. Besides high gas separation selectivity, capacity considerations in mixed gas phases are also important to check the performance of a given adsorbent. CO2 loading amounts in mixed gas phases are quite high as predicted through IAST calculation and experimentally determined from dynamic breakthrough studies. In order to get insight into the phenomena, GCMC simulation was performed demonstrating that the CO2 molecules are electrostatically trapped via interactions between oxygen on CO2 and hydrogen on pyridyl moieties of the spacers.

Three Co(II) Metal-Organic Frameworks with Diverse Architectures for Selective Gas Sorption and Magnetic Studies.

Three Co(II) metal-organic frameworks, namely, {[Co2(L)2(OBA)2(H2O)4]· xG} n (1), {[Co(L)0.5(OBA)]· xG} n (2), and {[Co2(L)2(OBA)2(H2O)]·DMA· xG} n (3) [where L = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene, H2OBA = 4,4'-oxybisbenzoic acid, DMF = dimethylformamide, DMA = dimethylacetamide, and G denotes disordered guest molecules], have been synthesized under diverse reaction conditions through self-assembly of a bent dicarboxylate and a linear spacer with a Co(II) ion. While 1 is crystallized at room temperature in DMF to form a 2D layer structure, 2 is formed by the assembly of similar components under solvothermal conditions with a 3D network structure. On the other hand, changing the solvent to DMA, 3 could be crystallized at room temperature with a 3D architecture. Out of the three, activated sample 2 was found to be permanently microporous in nature, with a BET surface area of 385 m2/g, and exhibited moderately high uptake capacity for C2H2 and CO2 while taking up much less CH4 and N2 at ambient conditions. As a result, high ideal adsorbed solution theory (IAST) separation selectivities are obtained for CO2/N2 (15:85), CO2/CH4 (50:50), and C2H2/CH4 (50:50) gas mixtures, making 2 a potential candidate for those important gas separations at ambient conditions. Moreover, the magnetic properties of 1-3 were studied. 1 and 2 show antiferromagnetic interaction between the Co(II) centers, whereas 3 displays ferromagnetic behavior arising from a counter-complementary effect between two types of links among Co(II) centers in 3.

A Moisture-Stable 3D Microporous CoII -Metal-Organic Framework with Potential for Highly Selective CO2 Separation under Ambient Conditions.

Selective adsorption and separation of CO2 from flue gas and landfill gas mixtures have drawn great attention in industry. Porous MOF materials are promising alternatives to achieve such separations; however, the stability in the presence of moisture must be taken into consideration. Herein, we have constructed a microporous metal-organic framework (MOF) {[Co(OBA)(L)0.5 ]⋅S}n (IITKGP-8), by employing a V-shaped organic linker with an azo-functionalized N,N' spacer forming a 3D network with mab topology and 1D rhombus-shaped channels along the crystallographic 'b' axis with a void volume of 34.2 %. The activated MOF reveals a moderate CO2 uptake capacity of 55.4 and 26.5 cm3 g-1 at 273 and 295 K/1 bar, respectively, whereas it takes up a significantly lower amount of CH4 and N2 under similar conditions and thus exhibits its potential for highly selective sorption of CO2 with excellent IAST selectivity of CO2 /N2 (106 at 273 K and 43.7 at 295 K) and CO2 /CH4 (17.7 at 273 K and 17.1 at 295 K) under 1 bar. More importantly, this MOF exhibits excellent moisture stability as assessed through PXRD experiments coupled with surface area analysis.

Polycarboxylate-Templated Coordination Polymers: Role of Templates for Superprotonic Conductivities of up to 10-1 †S cm-1.

Three coordination polymers (CPs) have been synthesized based on a [Co(bpy)(H2 O)4 ]2+ chain (bpy=4,4'-bipyridine) by a template approach. The frameworks are neutralized by different templated polycarboxylate anions (furan di-carboxylate (fdc) in Co-fdc, benzene tri-carboxylate (btc) in Co-tri and benzene tetra-carboxylate (btec) in Co-tetra). These templates with different degrees of protonation and ionic carrier concentration played significant role on crystal packing as well as formation of well-directed H-bonded networks which made these CPs perform well in proton conduction (PC). The PC value reaches to 1.49×10-1  S cm-1 under 80 °C and 98 % relative humidity (R.H.) for Co-tri, which is the highest among CPs/MOFs/COFs and is an example of conductivity in the order of 10-1  S cm-1 . Co-tri and Co-tetra are excellent proton conductors at mild temperature (40 °C) and 98 % R.H. (conductivities up to 2.92×10-2 and 1.38×10-2  S cm-1 , respectively).

Cp*CoIII-Catalyzed syn-Selective C-H Hydroarylation of Alkynes Using Benzamides: An Approach Toward Highly Conjugated Organic Frameworks.

Hydroarylation of internal alkynes by cost-effective CoIII-catalysis, directed by N-tert-butyl amides, is achieved to avail mono- or dihydroarylated amide products selectively in an atom and step economic way. Several important functional groups were tolerated under the reaction conditions, and syn-hydroarylation products were exclusively isolated. Notably, a 4-fold C-H hydroarylation provided a highly conjugated organic framework in one step. Kinetic study with extensive deuterium labeling experiments were performed to support the proposed mechanism.

A Water-Stable Twofold Interpenetrating Microporous MOF for Selective CO2 Adsorption and Separation.

Self-assembly of bent dicarboxylate linker 4,4'-sulfonyldibenzoic acid (H2SDB) and flexible N,N-donor spacer 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (L) with Co(NO3)2·6H2O forms a twofold interpenetrated {[Co2(SDB)2(L)]·(H2O)4·(DMF)}n, (IITKGP-6) network via solvothermal synthesis with sql(2,6L1) topology, which is characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis, powder X-ray diffraction (XRD), and single-crystal XRD. The framework is microporous with a solvent-accessible volume of 25.5% and forms a one-dimensional channel along [1-1 0] direction with the dimensions of ∼3.4 × 5.0 Å2. As the stability of metal-organic frameworks (MOFs) in the presence of water is a topic of significant importance while considering them for practical applications, this framework reveals its high stability toward water. The desolvated framework shows modest uptake of CO2 (50.6 and 37.4 cm3 g-1 at 273 and 295 K under 1 bar pressure, respectively), with high selectivity over N2 and CH4. Ideal adsorbed solution theory calculations show that the selectivity values of CO2/N2 (15:85) are 51.3 at 273 K and 42.8 at 295 K, whereas CO2/CH4 (50:50) selectivity values are 36 at 273 K and 5.1 at 295 K under 100 kPa. The high CO2 separation selectivity over N2 and CH4 along with its water stability makes this MOF a potential candidate for CO2 separation from flue gas mixture and landfill gas mixture as well.