Highly Efficient I2 Sorption, CO2 Capture, and Catalytic Conversion by Introducing Nitrogen Donor Sites in a Microporous Co(II)-Based Metal-Organic Framework.

Recently, the development of porous absorbents for efficient CO2 and I2 capture has attracted considerable attention because of severe global climate change and environmental issues with the nuclear energy. Hence, a unique porous metal-organic framework (MOF), {[Co(L)]·DMF·2H2O}n (1, DMF = N,N-dimethylformamide) with uncoordinated N atoms was rationally constructed via using a heterofunctional 4,6-bis(4'-carboxyphenyl)pyrimidine (H2L) linker. Interestingly, 1 exhibits exceptional properties for I2 sorption, CO2 capture, and catalytic conversion. Particularly, I2 can be efficiently removed in both vapor and solution forms, and the adsorption amount can reach 676.25 and 345.28 mg g-1, respectively. Furthermore, complex 1 displays high adsorption capacity for CO2 (53.78 cm3 g-1, 273 K). Consequently, 1 is expected to be a promising and practical material for environmental purification due to its excellent adsorption properties.

Lanthanide-Organic Frameworks with Uncoordinated Lewis Base Sites: Tunable Luminescence, Antibiotic Detection, and Anticounterfeiting.

Several new isostructural lanthanide metal-organic frameworks (Ln-MOFs), {[Ln2(L)3DMA4]·2DMA}n (1-Ln, where Ln = Eu, Tb, or EuxTb1-x), were first constructed via the solvothermal reactions of 4,6-di(4-carboxyphenyl)pyrimidine and Ln3+ ions. 1-Ln exhibits a 4-connected two-dimensional framework endowed with uncoordinated Lewis base sites. An exploration of luminescence sensing demonstrated 1-Eu can be used for the selectivity detection of dimetridazole and metronidazole antibiotics in other antibiotics, blood plasma, and urine, acting as an exceptional recyclable luminescent probe. More importantly, the luminescent inks of 1-Ln are invisible, color adjustable, and stabilized, which may greatly improve their anticounterfeiting applications.

Series of Water-Stable Lanthanide Metal-Organic Frameworks Based on Carboxylic Acid Imidazolium Chloride: Tunable Luminescent Emission and Sensing.

A series of isomorphic lanthanide metal-organic frameworks (Ln-MOFs), {[Ln(L)(H2O)2]·5H2O}n (1-Ln, where Ln = Eu, Tb, Gd, and EuxTb1-x), have been synthesized by a rigid 1,3-bis(3,5-dicarboxyphenyl)imidazolium chloride (H4L+Cl-) ligand and Ln3+ ions via a solvothermal method. Single-crystal X-ray diffraction indicated that 1-Ln exhibited similar three-dimensional porous frameworks with one-dimensional channels decorated by the uncoordinated carboxylate oxygen atoms. The luminescent sensing studies indicated that 1-Eu is an outstanding reusable luminescent probe suitable for the simultaneous detection of Cr2O72-, CrO42-, and MnO4- ions in an aqueous solution. Remarkably, the different proportions of Eu3+ and Tb3+ can be combined into the same Ln-MOF to yield a new series of differently doped 1-EuxTb1-x MOFs. At the same excitation wavelength, they generated dual-emission peaks of Eu3+ and Tb3+ to show a gradual change in luminous color between yellow-green, yellow, orange, orange-red, and red. On the basis of the excellent optical properties of 1-Ln complexes, they can be employed as promising luminescent probe and multicolor tunable photoluminescence materials.

Thiol-Functionalized Pores via Post-Synthesis Modification in a Metal-Organic Framework with Selective Removal of Hg(II) in Water.

Owing to the rapid increase of Hg(II) ions in water resources, the design and development of new adsorbents for Hg(II) removal are becoming a significant challenge in environmental protection. Herein, a thiol-functionalized metal-organic framework (SH-MiL-68(In)) was successfully prepared through a post-synthesis modification procedure, and the framework intactness and porosity were well maintained after this process. SH-MiL-68(In) exhibited selective adsorption performance for Hg(II) ions in water. Meanwhile, SH-MiL-68(In) also shows a high adsorption capacity (450 mg g-1), large adsorption rate (rate constant k2 = 1.25 g mg-1 min-1), and good recycling of adsorption capacity toward Hg(II) ions. The excellent adsorption performance resulted from the strong binding interactions between -SH soft basic groups and Hg(II) soft acidic ions.

A new stable luminescent Cd(ii) metal-organic framework with fluorescent sensing and selective dye adsorption properties.

A new luminescent metal-organic framework, {[Cd3(HL)2(H2O)3]·3H2O·2CH3CN}n (1) (H4L = 1-(3,5-dicarboxylatobenzyl)-3,5-pyrazole dicarboxylic acid), has been synthesized by solvothermal reaction and characterized by infrared spectroscopy, powder X-ray diffraction, thermogravimetry measurements and so on. 1 shows a new trinodal (4,4,6)-connected topology. Importantly, 1 displays intense luminescence in the solid state and high luminescent sensitivity and selectivity for Fe3+, CrO42- and Cr2O72- ions in aqueous solution, making it a potential probe for detecting these substances. The quenching mechanisms are also further discussed in detail. In addition, further research on the adsorption of dyes shows that 1 can selectively adsorb Congo red dye from other dye molecules.