Transition Metal Chemistry最新文献

Spinel ferrites with compositions Mg_xCo_1−xFe₂O₄ (x = 0.0 to 0.7) were synthesized using the wet chemical co-precipitation method. The structural analysis confirmed crystallite sizes ranging from 14 to 27 nm, calculated via the Debye–Scherrer equation and Williamson-Hall method. Optical studies revealed that the band gap increased from 2.15 eV for undoped cobalt ferrite (CoFe₂O₄) to 2.31 eV for Mg_0.5Co_0.5Fe₂O₄, suggesting improved optical properties with Mg doping. Morphological investigations using ImageJ software showed a decrease in average grain size from 65 to 33 nm with higher Mg doping, accompanied by smoother surfaces. Photocatalytic tests demonstrated significant degradation of Methylene blue (MB) dye under visible light irradiation. Optimal degradation of 25 ppm MB dye was achieved using 0.200 g/L Mg_0.5Co_0.5Fe₂O₄ ferrites and 0.435 mM hydrogen peroxide (H₂O₂) at pH 10.5. The degradation followed first-order kinetics, emphasizing the material’s potential as an efficient photocatalyst. This work indicates the role of Mg doping in developing the structural, optical, and photocatalytic features of spinel ferrites as a promising candidate for environmental remediation applications in the form of Mg_0.5Co_0.5Fe₂O₄.

II–VI semiconducting nanostructures are engrossed widely for their antibacterial studies against various pathogenic species. Their small size and morphology makes them imperative for their utilization in removal of bacteria. The present study is based on solvothermal synthesis and characterization of pristine and Mn-, Ni  Co and  Cu-doped zinc sulphide (ZnS) nanoparticles. X-ray diffraction results demonstrated the crystalline structure, and the cauliflower-like morphology is recorded through scanning electron microscopy. The average particle size was found to vary from 4 to 15 nm when scanned by high-resolution transmission electron microscopy (HRTEM). On doping with transition metals, the bandgap values were altered, and the emission spectra were shifted to higher wavelength region with diminished intensity. The affected zone of inhibition and minimum inhibitory concentration (MIC) values, calculated against five bacterial species, are found to vary from 25 to 200 μg/mL. The copper-doped ZnS sample having the least MIC values shows superior activity followed by Mn-doped ZnS, Ni-doped ZnS, Co-doped ZnS and undoped ZnS. Owing to the improved antibacterial activity, the synthesized nanoparticles can serve as the promising antibacterial agents in the medicinal field or as an antibiotic for other applications in near future.

Graphical abstract

Four 1,4-divinylphenylene-bridged diruthenium complexes [{Ru(CO)(κ²[N,S⁻]-L)(PⁱPr₃)₂}₂(μ-(CH=CH)₂–C₆H₄-1,4)] [IIa]–[IId] terminated with potentially non-innocent chelating κ²[N,S⁻] ligands of L derived of 2-mercaptopyridines or 2- or 8-mercaptoquinolines are presented. Those hexa-coordinated, 18-valence electrons (VEs) complexes were successfully prepared via subsequent treatment of the five-coordinated, 16-VEs [{Ru(CO)Cl(PⁱPr₃)₂}₂(μ-(CH=CH)₂–C₆H₄-1,4)] precursor [I] with the corresponding deprotonated bidentate κ²[N,S⁻] of 2-mercaptopyridines or 2- or 8-mercaptoquinolines. Our obtained results were compared to the closely related 1,4-divinylarylene-bridged diruthenium with κ²[N,O⁻] of 2-hydroxypyridines or 2- or 8-hydroxyquinolines. They were conventionally investigated in their neutral state via common NMR and UV/Vis/IR spectroscopic techniques, as well as in their two attainable redox states by UV/Vis/NIR, IR spectro(electro)chemistry as well as with cyclic voltammetry and with electron spin resonance. Those experimental results were complimented by the computational calculations. Our results refer that each 2-mercaptopyridines-derived complexes [IIa] and [IIb] existed as two geometrical isomers with a ratio of 1:18 that differed with respect to the orientation of the two κ²[N,S⁻] donor atoms relative to the C≡O and vinyl groups in the octahedral equatorial spheres, while in the case of the two-fused rings of 2- or 8-mercaptoquinolines-derived complexes [IIc] and [IId], however, only one isomer is formed, which is attributed to the steric hindrance reasons. Complexes [IIa]–[IId] undergo two consecutive, (electro)chemically reversible one-electron oxidation processes in low attainable potentials. All results refer to the strong contributions of the 1,4-divinylphenylene linker into the two individual redox processes and a full delocalization of the electron hole and the unpaired spin density over the entire π-conjugated 1,4-divinylphenylene diruthenium backbone with only minor involvement of the peripherally attached κ²[N,S⁻] donor ligands.

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CaWO₄/g-C₃N₄ nanocomposites were synthesized via ultrasonication method using pre-synthesized CaWO₄ and g-C₃N₄ nanostructures. CaWO₄ and g-C₃N₄ are combined to prepare an eco-friendly photocatalyst with high chemical stability. Furthermore, the synergetic effect of the band alignment of CaWO₄ and g-C₃N₄ forms a heterojunction, which facilitates the separation of photogenerated charge carriers and thus enhances the overall photocatalytic performance of the nanocomposites. The synthesized nanostructures were characterized via X-ray diffraction (XRD), UV‒Vis diffuse reflectance spectroscopy (UV‒Vis DRS), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity was assessed via degradation of Rhodamine-B (RhB) under visible light. In this study, the effects of reaction parameters such as initial pH, catalyst dosage, initial dye concentration, and contact time are explored. Under optimized conditions, (i.e., at pH=8, with 80 mg/L catalyst and 7.5 ppm RhB dye, the CaWO₄/g-C₃N₄ nanocomposites with 3% g-C₃N₄ (CC3) degrade nearly 98% of the RhB within 150 min. Among the various synthesized catalysts, CC3 has a high-rate constant of 27.03 × 10 ⁻³ min⁻¹. CC3 exhibited good cyclic stability and degradation efficiency even at the 5th cycle. Furthermore, trapping experiments revealed the importance of superoxide and holes during the photodegradation of RhB. In the present study, the photodegradation activity of CaWO₄/g-C₃N₄ nanocomposites was demonstrated, which may open new avenues for environmental remediation.

This review is the first to focus specifically on the interaction of metal complexes with surfactants, an area of growing interest due to its potential in improving solubility and biological properties. Drug-based metal complexes containing organic ligands often exhibit poor solubility in aqueous media, limiting their study and practical applications. The addition of surfactants plays a pivotal role in not only solubilizing these metal complexes but also enhancing their biological properties. The surfactant molecules can act as ligands, improving solubility while altering the morphology and coordination modes of complexes. This review provides a concise discussion of how surfactant interactions can enhance solubility and influence biological processes. It also covers the mechanism behind these interactions, their impact on bioavailability, and the techniques as well as factors that influence the interaction of surfactants with metal complexes.

Two manganese complexes formulated as [Mn(L¹)₂] (Mn1) and [Mn (L²)₂] (Mn2) (HL¹ = 2-acetylpyrazine N⁴-methylthiosemicarbazone, HL² = 2-acetylpyrazine N⁴-dimethylthiosemicarbazone) have been synthesized and characterized, and the molecular structure of complexes 1 and 2 have been determined by single-crystal X-ray diffraction. 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging test results suggest that HL² and its manganese complexes could exhibit efficient antioxidant abilities. The in vitro antibacterial properties of HL¹ and HL², also the two complexes, have been evaluated against E. coli and S. aureus, also Ampicillin-resistant E. coli and Kanamycin-resistant E. coli. The results indicated that HL² and Mn2 can present much more efficient antibacterial activity than Mn1 and HL¹. The in vitro cytotoxicity assay results showed that Mn2 exhibited appreciable cytotoxic activity against HCT-116 cells and HepG2 cells, and it also displayed efficient cancer selectivity. Upon comparing these results, it is indicated that minor differences in the structures of the two ligands had a significant impact on the biological activities of both the ligands and their manganese complexes.

Cancer is the leading cause of death worldwide. Regardless of advances in therapy, cancer remains a foremost concern, necessitating the development of new treatment options. Metal complexes are known to interact with DNA in different ways. The interactions between metal complexes and DNA interrupt the biological role of DNA in cell replication. This forms one of the modes of action of metal complexes. On these premises, the metal complexes possess valuable therapeutic potential for cancer. This review focuses on various copper and cobalt complexes synthesized using heterocyclic ligands. These have shown higher anticancer activity against different human cancer cell lines compared to the ligands alone. These complexes have demonstrated cytotoxicity, cell growth inhibition, cell cycle arrest, mitochondrial function disruption, oxidative stress induction, and DNA damage. Additionally, cobalt and copper complexes derived from different ligands have exhibited significant cytotoxicity against various cancer cell types, suggesting their potential as effective anticancer agents.

Graphical abstract

A new MOF, {[Fe₁₅(µ₃-O)₅(L⁴⁻)₆(H₂O)₁₃(CH₃COO)₈]Cl₃}n (SYU-3, SYU for Shenyang University, H₄L = [1,1′:4′,1″-triphenyl]-3,3″,5,5″-tetracarboxylic acid), with (3,3,4,4,4,4,4,4,5,6,7)-connected nets, was synthesized via the combination of H₄L with FeCl₃·6H₂O in N,N-dimethylformamide/acetic acid solvent system. Interestingly, SYU-3 is isomorphic to Quin-Fe-TPTC, which is a five-component MOF based on the same metal and ligand and possesses cages and channels in it. However, SYU-3 shows a different valence state of iron and was obtained by a one-step reaction without the need to prepare Fe–O clusters in advance. Moreover, SYU-3 exhibits high water stability, it also shows 10.4 wt% carbon dioxide adsorption amounts under 298 K and 1 bar and 84.7 adsorption selectivity of carbon dioxide to nitrogen. Grand canonical Monte Carlo simulations show that both cages and channels provide carbon dioxide binding sites, which may result in the selective carbon dioxide adsorption of SYU-3.

Herein, we reported the synthesis and characterization of two new iridium(III) complexes [Ir(ppy)₂(fpp)](PF₆) (Ir1a, ppy = 2-phenylpyridine, fpp = 2-(2,2-difluorobenzo[1,3]dioxol-5-yl-1H-imidazo[4,5-f][1,10]phenanthroline) and [Ir(bzq)₂(fpp)](PF₆) (Ir1b, bzq = benzo[h]quinoline) through high resolution mass spectrometry (HRMS), ¹H NMR and ¹³C NMR. The cytotoxicity in vitro of Ir1a and Ir1b on normal NIH3T3 cells and cancer SGC-7901, A549, SK-Hep1 cells was tested using MTT (3-(4,5-dimethylthiazole-2-yl)-diphenyltetrazolium bromide) method. Ir1a exhibits high cytotoxicity on SGC-7901 cells (IC₅₀ = 2.7 ± 0.7 µM), whereas Ir1b shows moderate cytotoxicity toward the selected cancer cells. The ROS content was investigated using a fluorescence probe of 2′,7′-dichlorodihydrofluorescein diacetate (DCHF-DA), the results show that Ir1a and Ir1b elevate ROS content. The co-localization and the change of mitochondrial membrane potential were explored. Apoptotic studies using Annex V/PI double staining method demonstrate that Ir1a and Ir1b can efficiently cause apoptosis. Ir1a and Ir1b inhibit the cell proliferation at the G2/M period. Additionally, lipid peroxidation and downregulation of ferritin protein suggest that Ir1a and Ir1b can trigger ferroptosis.

An equimolar mixture of 2-amino-6-methoxybenzothiazole and 2-hydroxy-4-methoxybenzaldehyde was used to produce a Schiff base ligand 5-methoxy-2-(((6-methoxybenzothiazol-2-yl)imino)methyl)phenol, HL, which was then examined by elemental analysis, IR, ¹H NMR, ¹³C NMR and ESI-mass spectrometry. The Co(II), Ni(II) and Cu(II) chlorides, acetates and ligands were combined in ethanol in a molar ratio of 1:1 to create the metal complexes [1-C₁₆H₁₉CoClN₂O₆S, 2- C₁₈H₂₂CoN₂O₈S, 3- C₁₆H₁₅NiClN₂O₄S, 4- C₁₈H₁₈NiN₂O₆S, 5- C₁₆H₁₅CuClN₂O₄S and 6- C₁₈H₁₈CuN₂O₆S]. To identify the structure of all metal complexes 1–6, elemental analysis, molar conductance, electronic spectra and IR spectra were used. The ligand HL functions as an uninegative bidentate via phenolic O- and azomethine N- atoms, according to spectral data. Theoretical studies were performed to investigate the interaction between the metal ions and the ligand HL. This included analysis of the HOMO–LUMO gap to assess electronic properties, Hirshfeld charge distribution to understand electron density changes upon complexation and calculation of the binding energy to evaluate the stability of the metal–ligand complexes. The Co(II) complexes have been given an octahedral geometry, Ni(II) complexes a tetrahedral geometry and Cu(II) complexes a square planar geometry. Studies of the binding of the metal complex to bovine serum albumin (BSA) have been undertaken with the aid of fluorescence and circular dichroism spectrometry.