Application of a Mixed-Ligand Metal-Organic Framework in Photocatalytic CO2 Reduction, Antibacterial Activity and Dye Adsorption

In this paper, a known mixed-ligand MOF {[Co₂(TZMB)₂(1,4-bib)_0.5(H₂O)₂]·(H₂O)₂}_n (compound 1) was reproduced, and its potential application potential was explored. It was found that compound 1 had high photocatalytic activity for CO₂ reduction. After 12 h of illumination, the formation rate of CO, which is the product of CO₂ reduction by compound 1, reached 3012.5 μmol/g/h. At the same time, compound 1 has a good antibacterial effect on Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albicans (C. albicans), which has potential research value in the medical field. In addition, compound 1 can effectively remove Congo Red from aqueous solutions and achieve the separation of Congo red from mixed dye solutions.

Synthesis of Hierarchical-Porous Fluorinated Metal-Organic Frameworks with Superior Toluene Adsorption Properties

Constructing metal-organic frameworks (MOFs) with high volatile organic compounds (VOCs) adsorption capacity and excellent water resistance remain challenging. Herein, a monocarboxylic acid-assisted mixed ligands strategy was designed to synthesize a novel fluorinated MOFs, MIL-53 (Al). The monocarboxylic acid promoted crystallization and produced abundant crystal defects, which increased pore volume. Moreover, the competitive coordination between tetrafluoroterephthalic acid and 1,4-dicarboxybenzene was moderated by monocarboxylic modulators, significantly improving the hydrophobicity. The toluene uptake of the optimal sample reached 254.85 mg g^-1 under humid conditions, increased by 33.56 % of MIL-53(Al), and the Q_Wet /Q_Dry (the ratio of adsorption quality under wet to adsorption quality under dry) was 0.92, remarkably surpassing that of origin MIL-53 (0.72). The recycle experiment showed superior reusability with no performance degradation after 10 recycle under RH=50 % (relative humidity). The adsorptive kinetic and thermodynamic analysis proves that the adsorption process is controlled by surface mono-layer adsorption and pore diffusion. The fluorine group affects the internal diffusion, which weakens the transfer rate. This strategy opens a new prospect of obtaining hierarchical functional MOFs for meeting the VOCs uptake under the practical application.

Exploring Anticancer Activities and Structure-Activity Relationships of Binuclear Oxidovanadium(IV) Complexes

Dimeric mixed-ligand oxidovanadium complexes [V₂O₂(1,3-pdta)(bpy)₂]·9H₂O (1) and [V₂O₂(1,3-pdta)(phen)₂]·6H₂O (2) feature a symmetric binuclear structure bridged by 1,3-pdta, which is different from our previous reported asymmetric binuclear complex [V₂O₂(edta)(phen)₂]·11H₂O (3).In this study, a wide range of analytical techniques were carried out to fully characterize the complexes 1 and 2 and further investigate their structural stabilities. Density functional theory calculations of 1 and 2 also suggest that they might have good reactivity with biomolecules as anticancer agents. To assess and screen the antitumor activities of compounds 1-3 together with their four corresponding monomeric complexes [VO(ida)(phen)], [VO(ida)(bpy)], [VO(OH)(phen)₂]Cl, and [VO(Hedta)]^-, we have performed in vitro experiments with hepatocellular carcinoma HepG2 and SMMC-7721 cell lines by MTT analyses. Complex 2 was found to have the highest inhibitory potency against the growth of HepG2 and SMMC-7721 cells (IC₅₀ = 2.07 ± 0.72 μM for HepG2; 13.00 ± 3.06 μM for SMMC-7721) compared to other compounds. The structure-activity relationship studies showed that the antitumor effect of compound 2 is higher than that of other compounds. After studying the monomeric compounds of 1-3, their effects were also ranked. Moreover, complex 2 displayed stronger binding affinity toward calf thymus DNA (K_b = 5.71 × 10⁴ M^-1) and cleavage activities than the other complexes (K_b = 1.34 × 10⁴ M^-1 for 1 and 5.22 × 10⁴ M^-1 for 3, respectively). We further extended the cellular mechanisms of drug action and found that 2 could block DNA synthesis and cell division of HepG2 and 7721 cells and further induce apoptosis by flow cytometry assays. In short, these results indicate that binuclear oxidovanadium compounds could have potential as simple, effective, and safe antitumor agents.

A new thermostable Cu(II) coordination polymer: photocatalytic activity and application values on diabetes

A Cu(II) coordination polymer with the composition of [Cu₂(L)₂(4,4'-bipy)₂]_n·2 n(ClO₄) (1, HL = 4-methyl-L-phenylalanine and 4,4'-bipy is 4,4'-bipyridine), was successfully obtained by the reaction of the mixed ligand of HL and 4,4'-bipy with Cu(ClO₄)₂ · 6H₂O under solvothermal condition. The as-synthesized compound not only has high thermal stability until 275°C but also excellent photocatalytic activity for the methyl blue solution degradation under the irradiation of ultraviolet light. Furthermore, the compound's treatment activity on the diabetes was determined and its relevant mechanism was also studied. The cytotoxicity or hemolysis toxicity (HC50) of the synthesized compound was also evaluated in this research.

Crystal structure of di-chlorido-[2-(di-phenyl-phosphan-yl)-3,4,5,6-tetra-fluoro-benzene-1-thiol-ato-κ(2) P,S]gold(III)

The title compound, [Au(C₁₈H₁₀F₄PS)Cl₂], crystallizes as neutral mol­ecules, with the Au^III atom coordinated by two Cl atoms and by the P and S atoms of the bidentate phosphanyl thiol­ate ligand, in a slightly distorted square-planar environment. The mol­ecules are linked into centrosymmetric dimers via long axial Au—Cl bonds of 3.393 (4) Å. This axial Au—Cl distance is longer than is usually seen, although one other example has been given. Dimer formation may explain the unexpectedly low solubility of the compound in common polar solvents. There is also a separate inter­molecular Au—F contact of 3.561 (6) Å, but this distance seems too long to be regarded as a bond. Two putative C—H⋯F hydrogen bonds appear to link the dimers into sheets parallel to (110). There is a short inter­molecular F⋯F contact of 2.695 (10) Å between two dimers related by the twofold axis.