Low and ambient temperature binding of oxygen, O₂, in MOF-74, CPO-27-M (M = Mn, Co, Ni, Cu, Zn) framework materials remains in the physisorption regime, with energetics very similar to that of nitrogen, N₂, sorption.

Objectives: The antimicrobial, oxidative activities, and ecotoxicity of synthesized silver-loaded zeolites (X and ZSM-5(MFI), Si-to-Al ratios 12 and 25) were studied, linking antimicrobial properties to material structure and released active silver species. Methods: The materials were characterized by SEM, EDX, TEM, and XRPD. All materials, with a silver content of 1–3%wt for the Ss and about 35%wt for the X-zeolites, were tested against Escherichia coli and Staphylococcus aureus. Redox activity was studied in physiological (pH 7.4/37 °C) and optimal (pH 8.5/37 °C) conditions in chemiluminescent model systems. In the ecotoxicity tests, we used Daphnia magna. Results: A proportional correlation was observed between the bactericidal effect of and the silver content in the zeolites. AgX with a Si/Al ratio of ~1.23 and 35% silver showed a higher antimicrobial efficiency, particularly against Gram-negative E. coli versus Gram-positive S. aureus. The concentration thresholds were as follows: AgXas had a bactericidal effect at 0.003 g/L⁻¹, with an MIC at 0.0015 m/L⁻¹ for E. coli; SA25-Ag, AgXcl, AgXrc had a bactericidal effect at 2.5 g/L⁻¹. The bacteria were more resilient than Daphnia magna, which showed a 90–100% lethality at Ag–zeolite concentrations of 0.00625 to 0.0125 g/L⁻¹. AgXas and AgXrc demonstrated strong reactive oxygen species generation at both the physiological and optimal pH, explaining their bactericidal effects. In general, the tested materials showed an inhibition of the generated reactive oxygen species depending on the model system and conditions. Conclusions: The silver species leached from the new materials explain their higher oxidation and bactericidal activity. While suitable for stringently controlled biological applications, their release into the environment, in concentrations higher than 0.01g/L⁻¹, should be avoided.

Structural changes and the unusual H₂ adsorption behaviour of a Cu²⁺-based MOF were studied by X-ray diffraction in combination with DFT modelling and by inelastic neutron scattering.

Four isostructural CPO‐54‐M metal‐organic frameworks based on the larger organic linker 1,5‐dihydroxynaphthalene‐2,6‐dicarboxylic acid and divalent cations (M=Mn, Mg, Ni, Co) are shown to be isoreticular to the CPO‐27 (MOF‐74) materials. Desolvated CPO‐54‐Mn contains a very high concentration of open metal sites, which has a pronounced effect on the gas adsorption of N₂, H₂, CO₂ and CO. Initial isosteric heats of adsorption are significantly higher than for MOFs without open metal sites and are slightly higher than for CPO‐27. The plateau of high heat of adsorption decreases earlier in CPO‐54‐Mn as a function of loading per mole than in CPO‐27‐Mn. Cluster and periodic density functional theory based calculations of the adsorbate structures and energetics show that the larger adsorption energy at low loadings, when only open metal sites are occupied, is mainly due to larger contribution of dispersive interactions for the materials with the larger, more electron rich bridging ligand.