MOF/polymer hybrids through free radical polymerization in metal-organic frameworks.

We use the free radical polymerization initiator 4,4'-azobis(cyanovaleric acid) coordinated to the open metal sites of metal-organic frameworks (MOFs) to give rise to highly uniform MOF/polymer hybrids. We demonstrate this strategy on two robust zirconium MOFs (NU-1000 and MOF-808), which are the most effective catalysts for degradation of chemical warfare nerve agents. The resulting hybrid materials maintain their hydrolytic catalytic activity and have substantially improved adhesion to polypropylene and activated carbon textile fibers, yielding highly robust MOF/polymer/textile hybrid systems.

Layer-by-Layer Integration of Zirconium Metal-Organic Frameworks onto Activated Carbon Spheres and Fabrics with Model Nerve Agent Detoxification Properties.

We report the controlled synthesis of thin films of prototypical zirconium metal-organic frameworks [ZrO(OH)(benzene-1,4-dicarboxylate-2-X)] (X = H, UiO-66 and X = NH, UiO-66-NH) over the external surface of shaped carbonized substrates (spheres and textile fabrics) using a layer-by-layer method. The resulting composite materials contain metal-organic framework (MOF) crystals homogeneously distributed over the external surface of the porous shaped bodies, which are able to capture an organophosphate nerve agent simulant (diisopropylfluorophosphate, DIFP) in competition with moisture (very fast) and hydrolyze the P-F bond (slow). This behavior confers the composite material self-cleaning properties, which are useful for blocking secondary emission problems of classical protective equipment based on activated carbon.

Mixed-Metal Cerium/Zirconium MOFs with Improved Nerve Agent Detoxification Properties.

A series of Ce/Zr mixed-metal-organic frameworks with different topology/connectivity, namely, Ce/Zr-UiO-66 (U01, U02, and U03) (fcu (12-c)), Ce/Zr-DUT-67-PZDC (D01 and D02) (reo (8-c)), and Ce/Zr-MOF-808 (M01, M02, and M03) (spn (6-c)) were evaluated toward the detoxification of toxic nerve agent model diisopropylfluorophosphate (DIFP) at room temperature in unbuffered aqueous solution. Noteworthily, the catalytic rate for P-F bond cleavage increased with increasing Ce/Zr molar ratio. A further increase in catalytic activity can be achieved by Mg(OMe) doping of the mixed-metal MOFs as exemplified with M01@Mg(OMe) and M02@Mg(OMe) systems.

Magnesium Exchanged Zirconium Metal-Organic Frameworks with Improved Detoxification Properties of Nerve Agents.

, and metal-organic frameworks exhibit a differentiated reactivity toward [Mg(OMe)(MeOH)] related to their pore accessibility. Microporous remains unchanged while mesoporous and hierarchical micro/mesoporous materials yield doped systems containing exposed MgZrO(OH) clusters in the mesoporous cavities. This modification is responsible for a remarkable enhancement of the catalytic activity toward the hydrolytic degradation of P-F and P-S bonds of toxic nerve agents, at room temperature, in unbuffered aqueous solutions.

Catalytically Active Imine-based Covalent Organic Frameworks for Detoxification of Nerve Agent Simulants in Aqueous Media.

A series of imine-based covalent organic frameworks decorated in their cavities with different alkynyl, pyrrolidine, and -methylpyrrolidine functional groups have been synthetized. These materials exhibit catalytic activity in aqueous media for the hydrolytic detoxification of nerve agents, as exemplified with nerve gas simulant diisopropylfluorophosphate (DIFP). These preliminary results suggest imine-based covalent organic frameworks (COFs) as promising materials for detoxification of highly toxic molecules.

A post-synthetic approach triggers selective and reversible sulphur dioxide adsorption on a metal-organic framework.

We report the application of a post-synthetic solid-state cation-exchange process to afford a novel 3D MOF with hydrated barium cations hosted at pores able to trigger selective and reversible SO adsorption. Computational modelling supports the full reversibility of the adsorption process on the basis of weak supramolecular interactions between SO and coordinated water molecules.

Chemical Warfare Agents Detoxification Properties of Zirconium Metal-Organic Frameworks by Synergistic Incorporation of Nucleophilic and Basic Sites.

The development of protective self-detoxifying materials is an important societal challenge to counteract risk of attacks employing highly toxic chemical warfare agents (CWAs). In this work, we have developed bifunctional zirconium metal-organic frameworks (MOFs) incorporating variable amounts of nucleophilic amino residues by means of formation of the mixed ligand [ZrO(OH)(bdc)(bdc-NH)] (UiO-66-xNH) and [ZrO(OH)(bpdc)(bpdc-(NH))] (UiO-67-x(NH)) systems where bdc = benzene-1,4-dicarboxylate; bdc-NH= benzene-2-amino-1,4-dicarboxylate; bpdc = 4,4'-biphenyldicarboxylate; bpdc-(NH) = 2,2'-diamino-4,4'-biphenyldicarboxylate and x = 0, 0.25, 0.