Polyoxometalate-based CuII/CoII complexes tuned using various metal–pyrazole loops: design, diverse architectures and catalytic activity toward the oxidation of thioether derivatives

Three new polyoxometalate-based complexes with unique metal–pyrazole loops were synthesized, showing various architectures and finally resulting in different catalysis performance.

Various amide-derived ligands induced five octamolybdate-based metal–organic complexes: synthesis, structure, electrochemical sensing and photocatalytic properties

Five octamolybdate-based complexes with diverse architectures employing three new amide-derived organic ligands can be used as promising electrochemical sensors and photocatalysts.

Hybrid compound based on diethylenetriaminecopper(ii) cations and scarce V-monosubstituted β-octamolybdate as water oxidation catalyst

Herein, we report on a new hybrid compound (NH₄){[Cu(dien)(H₂O)₂]₂[β-VMo₇O₂₆]}·1.5H₂O (1), where dien = diethylenetriamine, containing an extremely rare mixed-metal pseudo-octamolybdate cluster. An ex situ EPR spectroscopy provided insights into the formation of paramagnetic species in reaction mixture and in solution of 1. The magneto-structural correlations revealed weak antiferromagnetic exchange interactions between the [Cu(dien)]²⁺ cations transmitted by intermolecular pathways. The cyclic voltammetry showed the one-electron process associated with the Cu³⁺/Cu²⁺ oxidation followed by the multi-electron catalytic wave due to water oxidation with a faradaic yield of 86%. The title compound was thus employed in homogeneous water oxidation catalysis using tris(bipyridine)ruthenium photosensitizer. At pH 8.0, efficiency of the catalytic system attained 0.19 turnovers per second supported by the relatively mild water oxidation overpotential of 0.54 V.

A new hybrid compound (NH₄){[Cu(dien)(H₂O)₂]₂[β-VMo₇O₂₆]}·1.5H₂O was employed in homogeneous water oxidation catalysis. At pH 8.0, its efficiency attains 0.19 turnovers per second, supported by the relatively mild water oxidation overpotential of 0.54 V.

The rational design of four multifunctional octamolybdate-based complexes for detecting different ions and removing organic dyes from aqueous solution

Four new octamolybdate-based complexes were obtained and used not only as electrochemical sensors for sensing Cr(vi), Fe(iii), BrO₃⁻, and NO₂⁻ ions, but also as adsorbents to adsorb organic dyes.

Four octamolybdate complexes constructed from a quinoline–imidazole–monoamide ligand: structures and electrochemical, photocatalytic and magnetic properties

Four octamolybdate-based complexes synthesized by employing N-(quinoline-5-yl)-1H-imidazole-4-carboxamide as a ligand exhibit excellent electrocatalytic activities, photocatalytic properties and antiferromagnetic behavior.

Synthesis, characterization and bioactivities of a new covalent copper(II) compound derived from {P2Mo5O23}6- and thiosemicarbazones

In this article, a new compound H₂[{Cu(HL)(H₂O)}₂(P₂Mo₅O₂₃)]·5H₂O (1) (HL = 2-acetylpyrazine thiosemicarbazone) has been synthesized and structurally characterized by single-crystal X-ray diffraction of and other detection techniques. Interestingly, the structure of 1 is different from many reported copper-based complexes, in which the [P₂Mo₅O₂₃]^6-, two Cu²⁺ ions and two HL were directly connected by covalent bands. Biological studies demonstrated that 1 indicated moderate antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and a better cytotoxicity against human hepatic cancer line (SMMC-7721) than Mitoxantrone (Mito), the current clinical anticancer drug. Besides, the antibacterial mechanisms of 1 have been studied by the membrane integrity disruption, the destructive reactive oxygen species generation (ROS), the glutathione (GSH) depletion and the depressed enzymatic activity of respiratory chain dehydrogenases (RCD). These results revealed that the combination of HL, Cu²⁺, [P₂Mo₅O₂₃]^6- shows a higher antibacterial and cytotoxic activity.

Syntheses, structures and catalytic properties of Evans–Showell-type polyoxometalate-based 3D metal–organic complexes constructed from the semi-rigid bis(pyridylformyl)piperazine ligand and transition metals

Two 3D Evans–Showell-type POM-based different transition metals–bis-pyrazine–bis-amide complexes act as heterogeneous catalysts for the oxidation of benzyl alcohol.

Evans–Showell-type polyoxometalate-based metal–organic complexes with novel 3D structures constructed from flexible bis-pyrazine–bis-amide ligands and copper metals: syntheses, structures, and fluorescence and catalytic properties

Two 3D Evans–Showell-type POM-based copper–bis-pyrazine–bis-amide complexes show good heterogeneous catalytic activity for the oxidation of benzyl alcohol.