A Thermo-Responsive MOFs for X-Ray Scintillator

Thermo-responsive smart materials have aroused extensive interest due to the particular significance of temperature sensing. Although various photoluminescent materials are explored in thermal detection, it is not applicable enough in X-ray radiation environment where the accuracy and reliability will be influenced. Here, a strategy is proposed by introducing the concept of radio-luminescent functional building units (RBUs) to construct thermo-responsive lanthanide metal-organic frameworks (Ln-MOFs) scintillators for self-calibrating thermometry. The rational designs of RBUs (including organic ligand and Tb3+/Eu3+) with appropriate energy levels lead to high-performance radio-luminescence. Ln-MOFs scintillators exhibit perfect linear response to X-ray, presenting low dose rate detection limit (min ≈156.1 nGyairs-1). Self-calibrating detection based on ratiometric XEL intensities is achieved with good absolute and relative sensitivities of 6.74 and 8.1%K-1, respectively. High relative light yield (max ≈39000 photons MeV-1), imaging spatial resolution (max ≈18 lp mm-1), irradiation stability (intensity ≈100% at 368 K in total dose up to 215 Gyair), and giant color transformation visualization benefit the applications, especially the in situ thermo-responsive X-ray imaging. Such strategy provides a promising way to develop the novel smart photonic materials with excellent scintillator performances.

Ortho Effects of Tricarboxylate Linkers in Regulating Topologies of Rare-Earth Metal-Organic Frameworks

A linker design strategy is developed to attain novel polynuclear rare-earth (RE) metal-organic frameworks (MOFs) with unprecedented topologies. We uncover the critical role of ortho-functionalized tricarboxylate ligands in directing the construction of highly connected RE MOFs. The acidity and conformation of the tricarboxylate linkers were altered by substituting with diverse functional groups at the ortho position of the carboxyl groups. For instance, the acidity difference between carboxylate moieties resulted in forming three hexanuclear RE MOFs with novel (3,3,3,10,10)-c wxl, (3,12)-c gmx, and (3,3,3,12)-c joe topologies, respectively. In addition, when a bulky methyl group was introduced, the incompatibility between the net topology and ligand conformation guided the co-appearance of hexanuclear and tetranuclear clusters, generating a novel 3-periodic MOF with a (3,3,8,10)-c kyw net. Interestingly, a fluoro-functionalized linker prompted the formation of two unusual trinuclear clusters and produced a MOF with a fascinating (3,8,10)-c lfg topology, which could be gradually replaced by a more stable tetranuclear MOF with a new (3,12)-c lee topology with extended reaction time. This work enriches the polynuclear clusters library of RE MOFs and unveils new opportunities to construct MOFs with unprecedented structural complexity and vast application potential.

Rational Construction of Porous Metal-Organic Frameworks for Uranium(VI) Extraction: The Strong Periodic Tendency with a Metal Node

Although metal-organic frameworks (MOFs) have been reported as important porous materials for the potential utility in metal ion separation, coordinating the functionality, structure, and component of MOFs remains a great challenge. Herein, a series of anionic rare earth MOFs (RE-MOFs) were synthesized via a solvothermal template reaction and for the first time explored for uranium(VI) capture from an acidic medium. The unusually high extraction capacity of UO₂²⁺ (e.g., 538 mg U per g of Y-MOF) was achieved through ion-exchange with the concomitant release of Me₂NH₂⁺, during which the uranium(VI) extraction in the series of isostructural RE-MOFs was found to be highly sensitive to the ionic radii of the metal nodes. That is, the uranium(VI) adsorption capacities continuously increased as the ionic radii decreased. In-depth mechanism insight was obtained from molecular dynamics simulations, suggesting that both the accessible pore volume of the MOFs and hydrogen-bonding interactions contribute to the strong periodic tendency of uranium(VI) extraction.

Rare-earth metal–organic frameworks: from structure to applications

In the past 30 years, rare-earth metal–organic frameworks (MOFs) have been gaining attention owing to their diverse chemical structures, and tunable properties.

Flexible N-Donor Ligands Direct the Structural Characteristics of CoII Complexes: Syntheses, Structures, and Magnetic Properties

Solvothermal reactions of 3,3′,5,5′-biphenyltetracarboxylic acid (H4BPTC) and cobalt(ii) ions in the presence of two different flexible N-donor ancillary ligands afford two novel coordination polymers, {[Co(BPTC)0.5(bix)]·H2O}n (1), {[Co(BPTC)0.5(bpp)]·3H2O}n (2) (bix=1,4-bis(imidazol-1-ylmethyl)benzene; bpp=1,3-bis(4-pyridyl)propane). Their structures have been determined by elemental analyses, IR spectra, single-crystal X-ray diffraction analyses, and powder X-ray diffraction. The pillared layered framework of 1 can be simplified to a (4,6)-connected net with a Schläfli symbol of (44·62)(44·69·82). Complex 2 manifests a bilayered structure, and can be simplified to a (4,4)-connected net with a Schläfli symbol of (55·8)(54·62). The thermal stabilities of both complexes and the magnetic behaviours of 1 are also discussed.

3,5-Bis((4′-carboxylbenzyl)oxy)benzoilate-based coordination polymers: their synthesis, structural characterization, and sensing properties

The structural characterization of four 3,5-bis((4′-carboxylbenzyl)oxy)benzoilate-based coordination polymers has been reported, and the sensing ability of 2 and 4 on NB has been investigated.

Controllable synthesis of four series of lanthanide coordination polymers: synthesis, structures, luminescent and magnetic properties

Four series of lanthanide coordination polymers based on 2-(2-sulfophenyl)imidazo(4,5-f)(1,10)-phenanthroline and glutaric acid have been hydrothermally synthesized by changing the molar ratio and the pH value.

4-(4-Carboxyphenoxy)phthalate-based coordination polymers and their application in sensing nitrobenzene

Structural characterization of 4-(4-carboxyphenoxy)phthalate-based Cd²⁺ and Mn²⁺ coordination polymers are reported, and Cd²⁺ coordination polymer can serve as probe to sense nitrobenzene.