Applied Organometallic Chemistry最新文献

The current investigation involved the synthesis and detailed characterization of novel mixed-ligand complexes of Mn(II) (MnDPPNPH) and Cu(II) (CuDPPNPH). These complexes incorporate 2,6-di(1H-pyrazol-1-yl)pyridine (DPP) and a Schiff base derived from 2-hydroxy naphthaldehyde (NPH). The synthesized complexes revealed a stoichiometric ratio of 1:1:1 (metal:DPP:NPH), indicative of an octahedral coordination geometry around the Mn(II) and Cu(II) centers, as represented by the chemical formula [M (DPP)(NPH)(Cl)]. To elucidate their structural and electronic properties, theoretical calculations were performed. These calculations facilitated the optimization of the geometrical structures and provided insights into the molecular orbital characteristics of the complexes. The MnDPPNPH and CuDPPNPH complexes demonstrated potential phenoxazinone synthase mimicking activity by catalyzing aerial coupling of o-aminophenol (OAPh) to form phenoxazine-2-one (phenox). The mimicking activity of these complexes was quantitatively assessed using Michaelis–Menten enzymatic kinetics. Various enzyme kinetics plots were employed to determine several kinetic parameters, including the specificity constant and turnover number (k_cat), which are crucial for understanding the efficiency of the catalytic cycles. Remarkably, the synthesized MnDPPNPH and CuDPPNPH complexes exhibited significantly higher turnover numbers (k_cat) compared to previously reported complexes. This finding suggests that these new complexes possess superior catalytic activity, highlighting their potential as effective catalysts for reactions mimicking the function of phenoxazinone synthase.

Five new lanthanide complexes {[Sm(H₂L)(H₂O)₄(Cl)]⋅H₂O⋅Cl}_n (1), {[Eu(H₂L)(H₂O)₄Cl]⋅Cl}_n (2), {[La(H₂L)(H₂O)₄Cl]⋅Cl}_n (3), {[Pr(H₂L)(H₂O)₄Cl]⋅Cl}_n (4), {[Ce(H₂L)(H₂O)₄Cl]⋅Cl}_n (5) (H₃L = 2-hydroxy-5-(5-(hydroxy-λ²-methoxy)-1H-benzo[d]imidazole-5-carboxylic acid) were successfully synthesized under solvothermal method. 1 exhibits a two-dimensional (2D) network structure, whereas 2–5 feature one-dimensional (1D) chain structure. The fluorescence investigations demonstrated that 1–5 could be the fluorescent sensor for nitrobenzene (NB) and Fe(III) ions with high selectivity, sensitivity, and low detection limits. Furthermore, 1–5 displayed the good adsorption to anionic dye Congo red (CR), and the adsorption capacities were 140.5, 206.5, 212.5, 111.5, and 211.5 mg·g⁻¹, respectively.

We have developed a highly efficient, ligand-free Suzuki–Miyaura cross-coupling protocol employing our lab-prepared air and moisture-stable Pd-PEPPSI catalysts. The reaction of ethyl 2-{4-[(6-chloroquinoxalin-2-yl)oxy]phenoxy}propionate (Assure) with various boronic acids afforded both traditional and decarbonylative coupling products in high yields. The catalyst's steric influence was assessed computationally using %Vbur calculations. The decarbonylative coupling pathway proved more efficient than the traditional Suzuki–Miyaura coupling under these conditions. Additionally, regioselectivity studies have been conducted on a variety of Assure analogues. This method excels in efficiency, requiring minimal catalyst, moderate temperatures, and rapid reaction completion.

This study introduces a new electrochemical sensor for bisphenol A (BPA) and metal ions utilizing a microsphere dual-ligand Ni-based MOFs modified carbon paste. The MOFs (Ni-bipy-btc) synthesized from dual-ligands were prepared via a hydrothermal method and characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), FT-IR spectrometer, X-ray photoelectron spectrum (XPS), and specific surface area test (BET) analysis. The resulting MOFs exhibited promising performance as electrode materials for electrochemical sensors targeting the detection of BPA and heavy metal ions (Pb²⁺ and Cu²⁺). The linear range of the MOFs (Ni-bipy-btc)/CPE electrode for BPA detection ranged from 0.2 to 150 μM, with a detection limit of 0.045 μM, demonstrating robust immunity and stability. Additionally, the limit of detection for the MOFs (Ni-bipy-btc)/CPE electrode was found to be 4.3 and 9.5 nM for Pb²⁺ and Cu²⁺ ions, respectively, showcasing excellent stability and reproducibility. This study presents a straightforward approach for the highly sensitive electrochemical detection of BPA and heavy metal ions using a simple hydrothermal reaction method.

In this study, an efficient catalytic protocol using CuCoFe₂O₄@GO (CCF@GO) for the synthesis of amide bond (−CONH−) via direct coupling of carboxylic acids and N,N-dialkylformamides is presented. The CCF@GO nanocatalyst has been synthesized via a single-pot solvothermal method, by changing the proportions of copper and cobalt (1:1, 1:3, and 3:1). Catalyst screening, employing a model reaction with benzoic acid and dimethylformamide (DMF), revealed that the 1:1 proportion of CCF@GO catalyst exhibited excellent efficiency, achieving a high conversion (98%) towards amide formation. The enhanced catalytic efficiency observed in CCF@GO catalysts can be ascribed to the uniform distribution of active copper and cobalt species on the graphene oxide support, which possesses a high surface area. Optimization of the reaction was conducted by varying parameters such as temperature, solvent, catalyst loading, and oxidant. The prepared catalyst was characterized using various analytical techniques including XRD, FTIR, XPS, SEM, EDX mapping, and TEM. Furthermore, this heterogeneous nanocatalyst demonstrated recoverability using an external magnet and reused up to five times with just a modest loss of catalytic performance.

A series of bis(thiosemicarbazide)gallium (III) complexes were synthesized and characterized by infrared spectroscopy, mass spectrometry, nuclear magnetic resonance, single-crystal x-ray crystallography, and density functional theory (DFT) calculation. The cytotoxicity of these gallium(III) complexes (CP 1–4) was subsequently evaluated against HCT-116, HeLa, MDA-MB-231, and A549 cancer cell lines, as well as the normal cell line LO2, by MTT assays. The results indicated that CP-1 displayed potent inhibitory effects against human colorectal cancer cells (HCT-116) (IC₅₀ = 0.03 ± 0.01) and human breast cancer cells (MDA-MB-231) (IC₅₀ = 0.02 ± 0.01), significantly outperforming cisplatin. Moreover, CP-2 exhibited notable selectivity towards MDA-MB-231 cells (IC₅₀ = 5.01 ± 0.40) with minimal toxicity towards normal cells. Mechanistic studies revealed that treatment with CP 1–2 led to elevated intracellular reactive oxygen species (ROS) levels, resulting in cell cycle arrest at different phases. Specifically, CP-1 induced G2/M phase arrest, inhibiting cancer cell proliferation, whereas CP-2 hindered DNA synthesis (S phase) to impede cell proliferation. Furthermore, both CP-1 and CP-2 caused a reduction in mitochondrial membrane potential, activating the mitochondrial apoptotic pathway and inducing apoptosis in cancer cells. Molecular docking experiments demonstrated strong interactions between CP 1–2 and protein disulfide isomerase (PDI) at the molecular level. These findings suggest that CP-1 and CP-2 serve as potential anticancer agents, particularly showing promising potential in the treatment of breast cancer.

Biomimetic heterogeneous catalysts were prepared by immobilization of meso-tetrakis(4-carboxyphenyl)porphyrinatomanganese(III) acetate (MnTCPP) and meso-tetrakis(4-carboxyphenyl)porphyrinatoiron(III) chloride (FeTCPP) on graphitic carbon nitride (g-C₃N₄) nanosheets. The anchored catalysts were characterized by various techniques such as scanning electron microscopy, thermogravimetric analysis, powder X-ray diffraction, ultraviolet visible, photoluminescence, flame atomic absorption, and Fourier transform infrared spectroscopy. The thermogravimetric analysis demonstrated that the prepared catalysts were thermally stable up to almost 350°C, exhibiting high thermal stability. In the following, the catalytic efficiency of the prepared nanocatalyst was also investigated for the oxidation of various olefins with hydrogen peroxide (as a green oxidant) and the effect of various parameters which may affect the catalytic efficiency was optimized. The maximum conversion (100% for α-methylstyrene and 97% for cyclooctene) was obtained in the presence of MnTCPP@C₃N₄. The Mn porphyrin nanocatalyst shows higher catalytic efficiency compared to the Fe porphyrin.

Two isomeric homoleptic Ir(III) complexes with pyridinopyridazine derivative ligands were prepared first. Due to its stronger intramolecular hydrogen bonding and intermolecular interactions, complex IrPPM has a higher decomposition temperature (5% weight loss) of 387°C than IrPPP (354°C). They have similar UV–Vis absorption and photoluminescence spectra in CH₂Cl₂ solution with photoluminescence peaks around 635–636 nm. However, the emission peak of IrPPM in neat powder obviously red-shifted to 652 nm, and that of IrPPP blue-shifted to 626 nm. Simultaneously, complex IrPPM has a lower photoluminescence quantum yield of 0.3 than IrPPP (0.5). Efficient saturated red OLED devices are developed with Commission Internationale de L'Eclairage color coordinates of (0.67, 0.32) and (0.66, 0.32), respectively. The maximum external quantum efficiencies of both devices exceed 11%. These results demonstrate the great potential of pyridinopyridazine derivatives for developing new iridium complexes for OLED applications.

In the present work, new heterobimetallic complexes with the general formula [Zn(C₁₆H₃₂N₈)M₂(R)₄Cl₂], where M = Sn (IV) and Si (IV) and R = -CH₃ and -C₆H₅, were synthesized by reacting the methanolic solution of the monometallic complex [Zn(C₁₆H₃₆N₈)Cl₂] with group 14 organometallic dichloride [(CH₃)₂SnCl₂/(C₆H₅)₂SnCl₂/(CH₃)₂SiCl₂/(C₆H₅)₂SiCl₂]. The structures of the synthesized complexes were determined using several spectrometric techniques, including FT-IR, ¹H NMR, ¹³C NMR, ¹¹⁹Sn NMR, ²⁹Si NMR, ESI-MS, PXRD, and molar conductivity measurements. Density functional theory (DFT) calculations were carried out to investigate the quantum chemical characteristics of the newly synthesized Zn (II) complexes. The antimicrobial potential of the monometallic and heterobimetallic complexes was evaluated against two Gram-positive bacteria (Bacillus subtilis and Bacillus cereus), two Gram-negative bacteria (Xanthomonas campestris and Pseudomonas aeruginosa), and two fungal strains (Aspergillus flavus and Fusarium oxysporum) by the agar well diffusion method, with heterobimetallic complex [Zn(C₁₆H₃₂N₈)Sn₂(C₆H₅)₄Cl₂] as the most potent complex against microbes. The complex [Zn(C₁₆H₃₂N₈)Sn₂(C₆H₅)₄Cl₂] exhibited significant potential in inhibiting inflammation, demonstrating an IC₅₀ value of 9.75 μg/mL, which closely rivals that of the standard drug sodium diclofenac (IC₅₀ = 4.59 μg/mL). Furthermore, all the synthesized compounds were assessed for their anticancer potential against three cancer cell lines (HCT-116, MCF-7, and HeLa) by the MTT assay. The results indicated that the complex [Zn(C₁₆H₃₂N₈)Sn₂(C₆H₅)₄Cl₂] exhibited the most pronounced cytotoxic effects, with values of 4.25 ± 0.15 μM, 4.90 ± 0.18 μM, and 5.20 ± 0.24 μM observed for HCT-116, MCF-7, and HeLa cancer cell lines, respectively.

Novel compounds with pharmacological activity were synthesized from Pd(II), Fe(III), Cr(III), Ni(II), and Cu(II) ions with 1-cyclopropyl-6-fluoro-4-(2-hydroxy-phenylimino)-7-piperazin-1-yl-1,4-dihydro-quinoline-3-carboxylic acid (CFAP). The ligand's NH and OH groups allowed it to interact with the metals as a neutral tridentate. The investigated novel compounds were described using ¹H and ¹³C NMR spectra, FT-IR spectrums, TGA and UV–Vis (conductance of molecules), and CHN-analysis. Additionally, the pH profile of the CFAP complexes indicated great stability, and the complexes' stability constant was discovered in the solution. To extract important properties for CFAP and its complexes, computational research was used, CFAPCu, CFAPCr, CFAPNi, and CFAPFe have octahedral geometry, while CFAPPd has square planar geometry. To investigate the molecular geometry, density functional theory calculations (DFT) were carried out. The molar ratio and continuous fluctuation data confirmed that the (M:L) ratio was (1:1). In vitro tests were conducted to evaluate Schiff base's antimicrobial action ligand and its metal chelates against fungal and bacterial infections. The findings showed that the antimicrobial efficacy is as follows: When CFAPPd is compared to fluconazol and ofloxacin as reference medications, it is the highly inhibitor complex. The novel CFAP ligand and its complexes were investigated for In vitro carcinogenic potential against Hep-G2, MCF-7, and HCT-116 cell lines. As compared to the medication vinblastine, the results once again demonstrated that CFAPPd is the most active agent. Moreover, the complexes demnstrated strong reactivity in capturing free radicals when their antioxidant activity was investigated. Viscosity, spectral investigations, and gel electrophoreses were used to identify the interaction between metal chelates and DNA. Every examined compound is shown to be an enthusiastic DNA binder by viscosity and spectrophotometric titration investigations. The heightened hydrophobic and electrostatic interactions between aromatic rings could be the cause of this. Ultimately, these compounds could be regarded as promising bioactive substances.