Four cadmium(II) polymeric frameworks constructed by 2-methyl or 2-ethyl imidazole dicarboxylates

Two imidazole multicarboxylate-based MOFs: syntheses, structures and proton conductive properties

Two highly water-stable MOFs exhibited optimal σ values of around 10−4 S cm−1 at 98% RH and 100 °C, which can be compared to the values of previous MOFs.

Proton conduction in two Cu/Zn dimer-based hydrogen-bonded supramolecular frameworks from imidazole multi-carboxylate

At 98% RH and 100 °C, two dimer-based HSFs show the best σ values of 3.13 × 10⁻⁴ S cm⁻¹ for 1 and 0.55 × 10⁻⁴ S cm⁻¹ for 2, which can be compared to the values of reported HSFs.

A Highly Proton-Conductive 3D Ionic Cadmium-Organic Framework for Ammonia and Amines Impedance Sensing

Lately, the progressive study of metal-organic frameworks (MOFs) for the detection of ammonia and amines has made infusive achievements. Nevertheless, the investigation of proton-conductive MOFs used to detect the low concentrations of ammonia and amine gases at different relative humidities (RHs) at room temperature is relatively restricted. Herein, by solvothermal reaction of Cd(NO₃)₂ with 2-methyl-1 H-imidazole-4,5-dicarboxylic acid (H₃MIDC), a three-dimensional ionic MOF {Na[Cd(MIDC)]} _n (1) bearing ordered one-dimensional channels was successfully synthesized. Our research indicates that the uncoordination carboxylate sites are beneficial to proton transfer and the recognition of ammonia and amine compounds. The optimized proton conductivity of 1 reaches a high value of 1.04 × 10^-3 S·cm^-1 (100 °C, 98% RH). The room temperature sensing properties of ammonia and amine gases were explored under 68, 85, and 98% RHs, respectively. Satisfactorily, the detection limits of MOF 1 toward ammonia, methylamine, dimethylamine, trimethylamine, and ethylamine are 0.05, 0.1, 0.5, 1, and 4 ppm, respectively, which is one of the best room-temperature sensors for ammonia among previous sensors based on proton-conductive MOFs. The proton conducting and sensing mechanisms were highlighted as well.

Two luminescent transition-metal–organic frameworks with a predesigned ligand as highly sensitive and selective iron(iii) sensors

The water-stable imidazole dicarboxylated-based MOFs are excellent luminescent probes for the Fe³⁺ ion in an aqueous solution.

Design and synthesis of coordination polymers with chelated units and their application in nanomaterials science

The advances and problems associated with the preparation, properties and structure of coordination polymers with chelated units are presented and assessed.

Three Coordination Polymers Built by Methoxyphenyl Imidazole Dicarboxylate: Solvothermal Syntheses, Crystal Structures, and Properties

Three coordination polymers [Sr(p-H2MOPhIDC)2]n (1) (p-H3MOPhIDC = 2-p-methoxyphenyl-1H-imidazole-4,5-dicarboxylic acid), {[Cd2(p-HMOPhIDC)2(4,4′-bipy)]⋅H2O}n (4,4′-bipy = 4,4′-bipyridine) (2), and [Zn(p-HMOPhIDC)(4,4′-bipy)]n (3) have been solvothermally synthesized, and structurally characterized by single-crystal X-ray diffraction. Polymer 1 indicates a three-dimensional framework, which can be simplified as a 6-connected lattice. Polymer 2 is also a three-dimensional framework, and contains mixed bridging ligands HMOPhIDC2– and 4,4′-bipy. Polymer 3 exhibits a sheet structure bearing infinite rectangles. The coordination modes of the p-H3MOPhIDC ligand, and the thermal and solid-state photoluminescence properties of the polymers have been investigated as well.

Syntheses, crystal structures and thermal properties of six coordination polymers based on 2-(p-methylphenyl)-imidazole dicarboxylate

Through solvothermal reactions of 2-(p-methylphenyl)-1H-imidazole-4,5-dicarboxylic acid (p-MePhH3IDC) with transition-metal ions, six coordination polymers [Pb2(p-MePhHIDC)(p-MePhH2IDC)2(phen)2]n (phen = 1,10-phenanthroline) (), [Pb(p-MePhH2IDC)2]n (), [Cd3(p-MePhHIDC)2(p-MePhH2IDC)2(H2O)2]n (), {[Cd(p-MePhHIDC)(H2O)]4·H2O}n (), {[Cd2(p-MePhHIDC)2(4,4'-bipy)]·4H2O}n (4,4'-bipy = 4,4'-bipyridine) () and [Mn3(p-MePhHIDC)2(p-MePhH2IDC)2(4,4'-bipy)]n () have been synthesized successfully. X-ray single-crystal analyses show that polymers have rich structural chemistry ranging from one-dimensional (), two-dimensional () to three-dimensional polymers (, , and ). In these polymers, the p-MePhH3IDC ligand shows flexible coordination modes tuned by different synthetical conditions, including the addition of coligands, temperature, pH value and so on. Furthermore, the polymers have been investigated by solid-state ultraviolet spectra and thermogravimetric analyses.

A new three-dimensional silver(I) coordination framework with a diamondoid topology constructed from 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid

The title compound, poly[[μ4-5-carboxy-4-carboxylato-2-(pyridin-4-yl)-1H-imidazol-1-ido]disilver(I)], [Ag2(C10H5N3O4)]n, was synthesized by reacting silver nitrate with 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid (H3PyIDC) under hydrothermal conditions. The asymmetric unit contains two crystallographically independent Ag(I) cations and one unique HPyIDC(2-) anion. Both Ag(I) cations are three-coordinated in distorted T-shaped coordination geometries. One Ag(I) cation is coordinated by one N and two O atoms from two HPyIDC(2-) anions, while the other is bonded to one O and two N atoms from two HPyIDC(2-) anions. It is interesting to note that the HPyIDC(2-) group acts as a μ4-bridging ligand to link the Ag(I) cations into a three-dimensional framework, which can be simplified as a diamondoid topology. The thermal stability and photoluminescent properties of the title compound have also been studied.