Nitrito complexes of nickel(II), copper(II) and cobalt(II) with tridentate pyrazole based planer ligand: Structure, spectroscopy, thermal properties and imitative nuclease activity

Regeneration of NCM622 from end-of-life lithium-ion battery cathode materials

The boom of the electric vehicle industry significantly aggravates the demand for lithium-ion batteries (LIBs), especially the ternary cathode materials, however, the majority of end-of-life (EOL) LIBs on the market are batteries utilized in customer electronics. Here, we utilized the mixed EOL LIBs from cell phones and laptops to manufacture the LiNi_0.6Co0_.2Mn_0.2O₂ (NCM622) cathode material. A feasible, high efficiency (99.98% Co, 99.98% Ni, 99.99% Mn, and 99.99% Li), and ultra-fast leaching of EOL LIB cathodes was achieved. Thermodynamic calculations suggested that the coordination number, coordination species concentrations, and fractions have significant effects on the apparent activation energy and the equilibrium of the leaching reactions. The remanufactured NCM622 cathode material demonstrated a well-ordered layered hexagonal structure with a low Li⁺/Ni²⁺ mixing ratio, which facilitated reliable reversible capacity, low polarization, high rate capabilities (163.8 mA h g^-1), and capacity retention ratio (94.3%).

Structures, properties and applications of Cu(II) complexes with tridentate donor ligands

Tridentate ligands offer theree donor atoms to coordinate to metal ions. The remaining vacant coordination sites on the metal ions provided opportunities to implement additional co-ligands to generate complexes with desired properties. Herein we discuss selected examples of Cu(ii) complexes with tridentate ligands utilizing combinations of N, O, S, and Se donors, focusing on effects of ligand flexibility/rigidity on their coordination modes, properties and applications.

Synthesis, Characterization and Antibacterial Activity of Novel 1,3-Diethyl-1,3-bis(4-nitrophenyl)urea and Its Metal(II) Complexes

A bioactive ligand and its dinuclear metal(II) complexes were synthesized and characterized by Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-Visible), nuclear magnetic resonance (¹H-NMR), mass spectroscopy and molar conductance measurements. The ligand has been crystalized in the monoclinic system with a P21/c space group. The biological activities of metal complexes were evaluated using disc diffusion and broth dilution methods. In vitro antibacterial activities of the ligand and their metal complexes were examined against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Serratia marcescens) and compared to the standard drugs. It was found that metal complexes displayed much higher antibacterial activities and better inhibitory effects than that of the ligand and standard drugs. Among these complexes, the compound having Zn-metal showed greater antibacterial activity against all four tested bacteria and was more effective against Serratia marcescens with the zone inhibition diameter of 26 mm and MIC value of 31.25 µg/mL.

Synthesis, structural characterization and thermal properties of a new copper(II) one-dimensional coordination polymer based on bridging N,N'-bis(2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine and dicyanamide ligands

The design and synthesis of polymeric coordination compounds of 3d transition metals are of great interest in the search for functional materials. The coordination chemistry of the copper(II) ion is of interest currently due to potential applications in the areas of molecular biology and magnetochemistry. A novel coordination polymer of Cu(II) with bridging N,N'-bis(2-hydroxyphenyl)-2,2-dimethylpropane-1,3-diamine (H2L-DM) and dicyanamide (dca) ligands, catena-poly[[[μ2-2,2-dimethyl-N,N'-bis(2-oxidobenzylidene)propane-1,3-diamine-1:2κ(6)O,N,N',O':O,O']dicopper(II)]-di-μ-dicyanamido-1:2'κ(2)N(1):N(5);2:1'κ(2)N(1):N(5)], [Cu2(C19H20N2O2)(C2N3)2]n, has been synthesized and characterized by CHN elemental analysis, IR spectroscopy, thermal analysis and X-ray single-crystal diffraction analysis. Structural studies show that the Cu(II) centres in the dimeric asymmetric unit adopt distorted square-pyramidal geometries, as confirmed by the Addison parameter (τ) values. The chelating characteristics of the L-DM(2-) ligand results in the formation of a Cu(II) dimer with a double phenolate bridge in the asymmetric unit. In the crystal, the dimeric units are further linked to adjacent dimeric units through μ1,5-dca bridges to produce one-dimensional polymeric chains.