Ultrahigh proton conductivity of four ionic hydrogen-bonded organic frameworks based on functionalized terephthalates.

Recently, the utilization of hydrogen-bonded organic frameworks (HOFs) with high crystallinity and inherent well-defined H-bonding networks in the field of proton conduction has received increasing attention, but obtaining HOFs with excellent water stability and prominent proton conductivity (σ) remains challenging. Herein, by employing functionalized terephthalic acids, 2,5-dihydroxyterephthalic acid, 2-hydroxyterephthalic acid, 2-nitro terephthalic acid, and terephthalic acid, respectively, four highly water-stable ionic HOFs (iHOFs), [(CHO)(MeNH)]∙2HO (iHOF 1), [(CHO)(MeNH)] (iHOF 2), [(CHNO)(MeNH)] (iHOF 3) and [(CHO)(MeNH)] (iHOF 4) were efficiently prepared by a straightforward synthesis approach in DMF and HO solutions. The alternating-current (AC) impedance testing in humid conditions revealed that all four iHOFs were temperature- and humidity-dependent σ, with the greatest value reaching 10 S·cm.

Icing on the Cake: Imidazole-Anchored Strategy To Enhance the Proton Conductivity of Two Isostructural Ce(IV)/Hf(IV) Metal-Organic Frameworks.

In the field of proton conduction, the acquisition of crystalline metal-organic frameworks (MOFs) with high stability and ultrahigh proton conductivity has been of great research value and is worth continuous exploration. Here, we greenly synthesized a three-dimensional porous MOF () by using [(NH)Ce(NO) and fumaric acid as starting materials and solvothermally synthesized by using HfCl and 2-nitroterephthalic acid as starting materials. A series of measurements have shown that both MOFs exhibit good water stability, acid-base stability, and thermal stability and demonstrate outstanding proton conductivity.

Remarkable water-mediated proton conductivity of two porous zirconium(IV)/hafnium(IV) metal-organic frameworks bearing porphyrinlcarboxylate ligands.

Obtaining crystalline materials with high structural stability as well as super proton conductivity is a challenging task in the field of energy and material chemistry. Therefore, two highly stable metal-organic frameworks (MOFs) with macro-ring structures and carboxylate groups, Zr-TCPP (1) and Hf-TCPP (2) assembled from low-toxicity as well as highly coordination-capable Zr(IV)/Hf(IV) cations and the multifunctional linkage, meso-tetra(4-carboxyphenyl)porphine (TCPP) have attracted our strong interest. Note that TCPP as a large-size rigid ligand with high symmetry and multiple coordination sites contributes to the formation of the two stable MOFs.

Ultrahigh Proton Conductivities of Postmodified Hf(IV) Metal-Organic Frameworks and Related Chitosan-Based Composite Membranes.

Recently, researchers have focused on preparing and studying proton exchange membranes. Metal-organic frameworks (MOFs) are candidates for composite membrane fillers due to their high crystallinity and structural characteristics, and Hf-based MOFs have attracted our attention with their high porosity and high stability. Therefore, in this study, Hf-based MOFs were doped into a cost-effective chitosan matrix as fillers to fabricate composite films having excellent proton conductivity (σ).

Comparative Study on Proton Conductivity and Mechanism Analysis of Two Imidazole Modified Imine-Based Covalent Organic Frameworks.

This work elucidates the potential impact of intramolecular H-bonds within the pore walls of covalent organic frameworks (COFs) on proton conductivity. Employing DaTta and TaTta as representative hosts, it was observed that their innate proton conductivities (σ) are both unsatisfactory and σ(DaTta)<σ(TaTta). Intriguingly, the performance of both imidazole-loaded products, Im@DaTta and Im@TaTta is greatly improved, and the σ of Im@DaTta (0.

Two Dual-Function Zr/Hf-MOFs as High-Performance Proton Conductors and Amines Impedance Sensors.

In the field of sensing, finding high-performance amine molecular sensors has always been a challenging topic. Here, two highly stable 3D MOFs and with large specific surface areas and hierarchical pore structures were conveniently synthesized by solvothermal reaction of ZrCl/HfCl with a simple organic ligand, 2,5-thiophene dicarboxylic acid (HTDC) according to literature approach. By analyzing TGA data, it was found that the two MOFs have defects (unsaturated metal sites) that can interact with substrates (HO and volatile amine gas), which is conducive to proton transfer and amine compound identification.

Comparative Studies on the Proton Conductivities of Hafnium-Based Metal-Organic Frameworks and Related Chitosan or Nafion Composite Membranes.

Hafnium (Hf)-based UiO-66 series metal-organic frameworks (MOFs) have been widely studied on gas storage, gas separation, reduction reaction, and other aspects since they were first prepared in 2012, but there are few studies on proton conductivity. In this work, one Hf-based MOF, Hf-UiO-66-fum showing UiO-66 structure, also known as , was synthesized at room temperature using cheap fumaric acid as the bridging ligand, and then imidazole units were successfully introduced into to obatin a doped product, . Note that both and demonstrate excellent thermal, water, and acid-base stabilities.

Metal@COFs Possess High Proton Conductivity with Mixed Conducting Mechanisms.

The inherent porous structures and aligned functional units inside the skeleton of covalent organic frameworks (COFs) provide an extraordinary promise for post-modification and deservedly expand their application in the field of proton conduction. Herein, we tactfully introduced copper ions into a two-dimensional COF (TpTta) furnished with ample N,O-chelating sites by a post-modification strategy to achieve two copper(II)-modified products, namely, CuCl@TpTta-3 and CuCl@TpTta-10. Inspiringly, the two modified COFs demonstrated the higher conductivities of 1.

High Protonic Conductivity of Three Highly Stable Nanoscale Hafnium(IV) Metal-Organic Frameworks and Their Imidazole-Loaded Products.

Attracted by the exceptional structural rigidity and inherent porous structures of the Hf-based metal-organic frameworks (MOFs), we adopted a rapid synthesis approach to preparing three nanoscale MOFs, Hf-UiO-66 (), Hf-UiO-66-(OH) (), and Hf-UiO-66-NH (), and systematically explored the water-assisted proton conductivities of the original ones and the post-modified products. Interestingly, the proton conductivities (σ) of all three MOFs exhibit significant temperature and humidity dependence. At 98% RH and 100 °C, their optimal σ values can reach up to 10 S·cm.

Proton-Conductive 3D Ln Metal-Organic Frameworks for Formic Acid Impedance Sensing.

Metal-organic frameworks (MOFs) as new classes of proton-conducting materials have been highlighted in recent years. Nevertheless, the exploration of proton-conducting MOFs as formic acid sensors is extremely lacking. Herein, we prepared two highly stable 3D isostructural lanthanide(III) MOFs, {(M(μ -HPhIDC)(μ -C O ) (H O))⋅2 H O} (M=Tb (ZZU-1); Eu (ZZU-2)) (H PhIDC=2-phenyl-1H-imidazole-4,5-dicarboxylic acid), in which the coordinated and uncoordinated water molecules and uncoordinated imidazole N atoms play decisive roles for the high-performance proton conduction and recognition ability for formic acid.

Two Highly Stable Proton Conductive Cobalt(II)-Organic Frameworks as Impedance Sensors for Formic Acid.

Metal-organic frameworks (MOFs) have been extensively explored as advanced chemical sensors in recent years. However, there are few studies on MOFs as acidic gas sensors, especially proton conductive MOFs. In this work, two new proton-conducting 3D MOFs, {[Co (p-CPhHIDC) (4,4'-bipy)(H O)]⋅2 H O} (1) (p-CPhH IDC=2-(4-carboxylphenyl)-1 H-imidazole-4,5-dicarboxylic acid; 4,4'-bipy=4,4'-bipyridine) and {[Co (p-CPhHIDC) (bpe)(H O)]⋅3 H O} (2) (bpe=trans-1,2-bis(4-pyridyl)ethylene) have been solvothermally prepared and investigated their formic acid sensing properties.

[Analysis of rational clinical uses of traditional Chinese medicine injections and factors influencing adverse drug reactions].

Objective: To rationalize the clinical use and safety are some of the key issues in the surveillance of traditional Chinese medicine injections (TCMIs).

Method: In this 2011 study, 240 medical records of patients who had been discharged following treatment with TCMIs between 1 and 12 month previously were randomly selected from hospital records. Consistency between clinical use and the description of TCMIs was evaluated.