Water-Stable Metal–Organic Framework with Three Hydrogen-Bond Acceptors: Versatile Theoretical and Experimental Insights into Adsorption Ability and Thermo-Hydrolytic Stability

Abstract

A new microporous cadmium metal-organic framework was synthesized both mechanochemically and in solution by using a sulfonyl-functionalized dicarboxylate linker and an acylhydrazone colinker. The three-dimensional framework is highly stable upon heating to 300 °C as well as in aqueous solutions at elevated temperatures or acidic conditions. The thermally activated material exhibits steep water vapor uptake at low relative pressures at 298 K and excellent recyclability up to 260 °C as confirmed by both quasi-equilibrated temperature-programmed desorption and adsorption (QE-TPDA) method as well as adsorption isotherm measurements. Reversible isotherms and hysteretic isobars recorded for the desorption-adsorption cycles indicate the maximum uptake of 0.19 g/g (at 298 K, up to p/p = 1) or 0.18 g/g (at 1 bar, within 295-375 K range), respectively. The experimental isosteric heat of adsorption (48.9 kJ/mol) indicates noncoordinative interactions of water molecules with the framework. Exchange of the solvent molecules in the as-made material with water, performed in the single-crystal to single-crystal manner, allows direct comparison of both X-ray crystal structures. The single-crystal X-ray diffraction for the water-loaded framework demonstrates the orientation of water clusters in the framework cavities and reveals their strong hydrogen bonding with sulfonyl, acyl, and carboxylate groups of the two linkers. The grand canonical Monte Carlo (GCMC) simulations of HO adsorption corroborate the experimental findings and reveal preferable locations of guest molecules in the framework voids at various pressures. Additionally, both experimental and GCMC simulation insights into the adsorption of CO (at 195 K) on the activated framework are presented.

Large breathing effect induced by water sorption in a remarkably stable nonporous cyanide-bridged coordination polymer

“…The QE-TPDA profiles present positive signals when excess water is desorbed from the sample or negative signals when carrier gas is being depleted of the adsorbate. Recently, the method has been proven useful in studies of water sorption in MOFs 103,104 and cyanide-bridged assemblies. 105 The QE-TPDA profiles of 1Mn•8H 2 O demonstrate a three-step desorption process (Figure 5), which is in line with the aforementioned water desorption isotherm.…”

“…The QE-TPDA measurements were performed using a homemade thermodesorption apparatus (equipped with a VICI Microvolume TCD-2 thermal conductivity detector, electronic mass flow controllers of the carrier gas Brooks 5850, and a passive room temperature saturator) described in details elsewhere. [100][101][102][103][104] TGA was performed using a NETZSCH TG 209 F1 Libra under a flow of nitrogen (20 mL/min). The DSC measurement was performed with the use of a Mettler Toledo DSC 822e.…”

Guest‐Dependent Pressure‐Induced Spin Crossover in FeII4[MIV(CN)8]2 (M=Mo, W) Cluster‐Based Material Showing Persistent Solvent‐Driven Structural Transformations

“…At horough analysis of solvent-induced structural changesa nd the investigation of sorption properties of the tested materials were conducted by meanso fp owder X-ray diffraction, TGA, IR, dynamic vapor sorption, and quasi-equilibrated temperatureprogrammed desorption and adsorption (QE-TPDA). [39][40][41][42][43][44][45][46] Powder X-ray diffraction…”

Large Breathing Effect Induced by Water Sorption in the Exceptionally Stable Nonporous Non-MOF Crystalline Material

“…The QE-TPDA profiles present positive signals when excess water is desorbed from the sample or negative signals when carrier gas is being depleted of the adsorbate. Recently, the method has been proven useful in studies of water sorption in MOFs 97,98 and cyanide-bridged assemblies 99 . The QE-TPDA profiles of 1Mn•8H2O demonstrate a three-step desorption process (Figure 4), which is in line with the aforementioned water desorption isotherm.…”

“…The QE-TPDA measurements were performed using a homemade thermodesorption apparatus (equipped with a VICI Microvolume TCD-2 thermal conductivity detector, electronic mass flow controllers of the carrier gas Brooks 5850, and a passive room temperature saturator) described in details elsewhere. [94][95][96][97][98] TGA was performed using a NETZSCH TG 209 F1 Libra under a flow of nitrogen (20 mL/min). The DSC measurement was performed with the use of a Mettler Toledo DSC 822e.…”