From Hydrogen Bond to van der Waals Force: Molecular Scalpel Strategy to Exfoliate a Two-Dimensional Metal-Organic Nanosheet

The facile exfoliation of a two-dimensional metal-organic nanosheet of {[Co(HL)(H₂O)(Py)_3/4]·¹/₂H₂O·DMF}_n [1-Py; H₃L = 5-(1H-pyrazol-4-yl)isophthalic acid and Py = pyridine] was achieved, via a molecular scalpel strategy, by weakening intermolecular forces between adjacent layers. The resulting 1-Py/KB40 (KB = Ketjen black) shows an increased oxygen evolution reaction (OER) performance with an overpotential of 370 mV at a current density of 10 mA cm^-2 and a Tafel slope of 58 mV dec^-1. This work sheds light on the structure-morphology-reactivity relationship of such materials in OER.

Molecular engineering in a family of pillared-layered metal-organic frameworks for tuning gas adsorption behavior

In this work, inspired by a water-assisted three-dimensional supramolecular structure 1, we use a mixed-ligand strategy to form a 3D pillared-layered matrix by the introduction of linear ligands to compete against the water molecules. The resulting analogue microporous MOFs of 2-H, 2-F and 2-N, decorated with different functional groups, similarly show the CO2 uptake. Thanks to the negligible N2 adsorption capacity, enhanced selective adsorption towards CO2 is achieved in compound 2-N. That is, we present here an alternative plan for the high CO2 selective adsorption performance. In addition, the structure stability and moderate affinity for CO2 of these microporous MOFs endow them with excellent reusability.

Tetrazole-based porous metal–organic frameworks for selective CO2 adsorption and isomerization studies

Tetrazole-based porous MOFs and isomers were synthesized for adsorbing carbon dioxide, showing high selectivity.

Three metal–organic framework isomers of different pore sizes for selective CO2 adsorption and isomerization studies

Three MOF isomers including framework-catenation and framework-topological isomers were synthesized for adsorbing carbon dioxide with high selectivity.

Effective adsorption of Congo red by a MOF-based magnetic material

A highly water-stable MOF-based magnetic material Fe₃O₄@ZTB-1 has been obtained, and it exhibited an excellent adsorption capacity for Congo red. The electrostatic interactions and hydrogen bond are responsible for binding of CR with Fe₃O₄@ZTB-1.

Two MOFs as dual-responsive photoluminescence sensors for metal and inorganic ion detection

Two MOFs were synthesized and explored as dual-responsive photoluminescent sensors: 1 for Fe³⁺ and Cr₂O₇²⁻ ions, and 2 for Hg²⁺ and Cr₂O₇²⁻ ions.

Effect of Co-Crystal Formers on the Supramolecular Patterns and Luminescence Properties of Co-Crystals Comprising Fenbufen and Diverse N-Heterocycles

Four co-crystals [(2-apy)·(Fbf)] (1), [(2-apz)·(Fbf)] (2), [(4,4′-bipy)·2(Fbf)] (3), and [(4,4′-bpe)·2(Fbf)] (4) (Fbf = fenbufen, 4-(4-biphenylyl)-4-oxobutyric acid, 2-apy = 2-aminopyridine, 2-apz = 2-aminopyrazine, 4,4′-bipy = 4,4′-bipyridine, 4,4′-bpe = trans-1,2-bis(4-pyridyl)ethene) have been obtained from the reaction of Fbf and different N-heterocycles by either liquid-assisted grinding method or solution evaporation, and characterized by elemental analysis, infrared spectroscopy, differential scanning calorimetry, photoluminescence spectroscopy, and powder- and single-crystal X-ray diffraction. Structural analyses indicate that conformations of Fbf molecules are highly related to the lone pair···π, C–H···π, or C–H···O interactions, which lead to the formation of different dihedral angles in the four planes in Fbf. With these non-covalent interactions, Fbf presents trans conformation in compounds 1, 3, 4, and cis conformation in compound 2. Interestingly, the packing diagrams of compounds 1 and 2 are very similar to the different trigonometric functions. Compounds 3 and 4 exhibit discontiguous packing diagrams with short snake-shaped chains owing to the higher symmetry of 4,4′-bipy and 4,4′-bpe molecules. Moreover, the differential scanning calorimetry analyses indicate the lower melting point of all compounds when compared with that of free Fbf. Luminescence investigation shows that only compound 1 exhibits strong blue emission in the solid state at room temperature.

Macrocyclic dinuclear, helical, layered and 3-D Ag(i) complexes constructed from AgX (X = NO3− and ClO4−) and flexible bis(pyridyl) ligands with a chelating spacer: syntheses, structures and photoluminescence properties

Eight novel Ag(i)-bis(pyridyl) complexes with diverse structures have been synthesized.

Evaluation of penetrating keratoplasties with long-term cryopreserved corneas using simplified method

Since March 1986, the authors have studied and simplified the corneal cryopreservation technique using a self-made QL Bio-freezer. On the basis of successful animal experiments, penetrating keratoplasties with human cadaver corneas cryopreserved 9 to 571 days (averaging 131 days) were performed in 60 patients (61 eyes). The patients were followed up for 1.5 to 50 months. 41 of the corneal grafts remained clear, 9 became translucent and 11 cloudy. A total of 46 eyes had their visual acuity improved significantly. The results show that clinical use of corneal cryopreservation by the simplified two-step method is noteworthy.