2D → 3D corrugated structure self‐assembled from 4,4′‐methylenebis( N ‐(pyridin‐2‐ylmethylene)aniline and terephthalic acid: Crystal structure and selective anion separations via anion exchange

A bifunctionalised Pb-based MOF for iodine capture and dye removal

A 2-dimensional Pb(II) metal-organic framework, [Pb(bdc)_0.5(py-Phen)NO₃]_n (SM-3), was synthesized under solvothermal conditions using a mixed ligand approach. SM-3 was assembled using dinuclear SBUs [Pb₂(COO)₂]^2-, an oxygen donor H₂bdc = 1,4-benzene dicarboxylic acid, and nitrogen donor py-Phen = pyrazino[2,3-f][1,10]-phenanthroline linkers. SM-3 was characterized by elemental analysis, FT-IR, powder-X-ray diffraction, thermal gravimetric analysis, SEM, EDS, TEM, and single-crystal X-ray diffraction techniques. Crystallographic studies confirmed that SM-3 displays a 2D layered structure with unique anagostic (Pb⋯H) interactions. Interestingly, the presence of abundant π-electron-rich rings embellished with free -N donor sites in the framework makes SM-3 an excellent adsorbent that exhibits adsorption performance for iodine and dyes. The experimental results show that SM-3 reversibly adsorbs radioactive iodine in the solution and vapor phases and exhibits selective adsorption performance for hazardous cationic dyes, namely, methylene blue (MB) and rhodamine-B (Rh-B), from aqueous solution. Moreover, the possible mechanism of iodine and dye adsorption was also discussed in detail. Thus, this work is remarkable for coordination chemists to engineer layered MOFs for adsorption purposes and expands their potential characteristics by converting them into 2D MOF nanosheets to further enhance the adsorption of hazardous pollutants for environment protection.

A copper(ii)-based porous metal-organic framework for the efficient and rapid capture of toxic oxo-anion pollutants from water

The efficient and selective capture of toxic oxo-anions is highly desirable for environmental retrieval and hazardous waste disposal. This has remained an important task and gained considerable scientific attention due to their harmful effects on the ecosystem and human health. Herein, a porous cationic metal-organic framework (MOF), namely, [Cu₃Cl(L)(H₂O)₂]·Cl·4DMA·8H₂O (1), was synthesized (H₄L = 1,4,8,11-tetrazacyclotetradecane-N,N',N'',N'''-tetramethylenecinnamic acid and DMA = N,N'-dimethylacetamide). 1 shows high stability in aqueous solution and represents an extraordinary example that is capable of efficiently capturing environmentally toxic Cr₂O₇^2- and MnO₄^- anions. Moreover, the removal of Cr₂O₇^2- and MnO₄^- anions from water was also explored in the presence of other competing anions.

Anion exchange strategy to improve electrocatalytic hydrogen evolution performances in cationic metal–organic frameworks

Through an anion exchange strategy, the post-synthetic cationic metal–organic frameworks present better electrocatalytic performances during the hydrogen evolution reaction process than the pristine one.

Two new luminescent Cd(ii)-based coordination polymers by regulating the asymmetrical tetracarboxylate and auxiliary ligands displaying high sensitivity for Fe3+ and CrO42−

The results showed luminescence spectra with emission intensities significantly quenched towards Fe³⁺ and CrO₄²⁻. The low concentrations of the two ions indicate high sensitivities of the synthesized compounds towards analytes.