Applied Organometallic Chemistry最新文献

This study examined the adsorption capacities of biochars derived from kenaf (KF-BCs) for the removal of heavy metals such as Cu(II) and Pb(II). The thermal decomposition temperature (300–750°C) significantly influenced the morphology and composition of KF-BCs, enhancing their surface area, pore structure, and alkalinity. Among them, kenaf pyrolyzed at 750°C (KF-750) was the most effective in removing Cu(II) and Pb(II), as validated by kinetic, equilibrium, and isotherm model analyses. Adsorption kinetics revealed that equilibrium was attained after 24 h, with chemisorption governing the process rate. Equilibrium adsorption conformed to the Langmuir and Freundlich models for Cu(II) and Pb(II), respectively. KF-750 exhibited midrange adsorption capacities for Cu(II) and Pb(II) (23.47 ± 0.3 mg/g and 50.07 ± 0.9 mg/g, respectively), compared with the literature. The thermodynamic assessment revealed an endothermic process with positive ∆H⁰, indicating that higher temperatures favor metal adsorption. At low pH, adsorption decreased due to electrostatic repulsion, particularly affecting Cu(II). More than 99.8% of Cu(II) and Pb(II) were removed with a 5.00 g/L KF-750 dose. The cation effect order on KF-750 was Ca²⁺ > Mg²⁺ > Na⁺ > K⁺. Overall, KF-750 demonstrates promising potential as an adsorbent for the efficient heavy metal removal from aqueous solutions, presenting a viable option for environmental remediation.

Treatment of two classes of oxazolinyl-indolate ligand precursors with an equivalent trimethylaluminum reagent afforded four corresponding aluminum dimethyl complexes. Intramolecular functional groups were employed to switch coordination behaviors, resulting in the formation of two classes of five- or six-membered aluminum metallocyclic complexes. The screening of the prepared aluminum complexes, mediated by 9-anthracenemethanol as the initiating reagent in the ring-opening polymerization of ε-caprolactone, showed significant activities at room temperature. The aluminum compound ligated by 2-(1H-indol-2-yl)-4,4-dimethyl-4,5-dihydrooxazole possessed a suitable chelated ring size, and its intrinsic electronic properties maintained higher activity.

In this study, we present the successful application of new and known stable 16-electron ruthenium(II) pincer complexes POCOP, based on the naphthoresorcinate backbone, [Ru(X)(POCOP)(CO)] (X = H, Cl, Br, I, OCOCF₃), in the catalytic alkylation of ketones and the coupling between amines and primary alcohols under mild conditions. These protocols demonstrated tolerance to a wide range of alcohols, ketones, and anilines, with reactions proceeding in high conversions and selectivity towards the hydrogenated ketones and the imines. The use of an excess of alcohol as the proton source facilitated the formation of the hydrogenated products. These results mark a significant advancement in the development of catalytic reactions with ruthenium POCOP pincer derivatives.

DNA-binding agents often exhibits dual behavior of simultaneous binding with protein associated with cancerous cell development pathways. This simultaneous protein binding if contributed to malfunctioning of pro-apoptotic proteins will reduce anticancerous potential of drugs. The elucidation of binding target for anticancerous agent can give an insight into the cancer cell apoptotic pathway. Therefore, anticancerous Zn(II) and Ni(II) complexes of 2-guanidinobenzimidazole (2GBz) were subjected to DNA-binding mode assay along with protein-binding interference assay. The stoichiometry Zn-2GBz and Ni-2GBz were determined through density functional theory (DFT) and UV–Vis spectroscopy, followed by structural verification by X-ray crystallography. The 2GBz and Ni-2GBz were found to bind with grooves of DNA while groove binding of Zn-2GBz induced unwinding of DNA through interactive pi-stacking. Binding constant revealed the M-2GBz to be a strong binder of DNA molecule with the effect of enhanced cell killing potential of M-2GBz against MCF-7 cell lines. Protein-binding assay revealed that despite of significant interaction of M-2GBz with chick serum albumin, DNA binding was not altered by simultaneous protein binding. The most potent Zn-2GBz was found to be sphingosine 1 kinase 2 (SPhK2) which can be a cause of enhanced cancer cell apoptosis with lesser normal cell apoptosis than standard fluorouracil in MCF-7 cell lines. Co-administered Zn-2GBz increased cancer cell sensitivity towards fluorouracil as potent anticancerous agent.

In this article, initially, the TCTCl (DiPrAEA)₂ ligand was synthesized and characterized by Fourier transform infrared (FT-IR), X-ray crystallography, ¹H- and ¹³C-NMR spectroscopy, and elemental analysis. The crystallographic structure data for the ligand has been deposited at the Cambridge Crystallographic Data Centre (CCDC No. 2282732). Then, using of this novel multidentate ligand, a novel and stable copper (II) nanocatalyst complex was synthesized by anchoring copper (II) acetate onto the core-shell surface (Fe₃O₄@SiO₂) via the novel multidentate ligand TCTCl (DiPrAEA)₂. The successful synthesis of the Fe₃O₄@SiO₂-NH-TCT (DiPrAEA)₂-Cu (II) nanocatalyst was confirmed by employing physicochemical techniques such as FT-IR, X-ray diffraction, ultraviolet-visible, thermogravimetric analysis, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller, energy-dispersive X-ray, dynamic light scattering, inductively coupled plasma, transmission electron microscopy, field emission scanning electron microscopy, and vibrating sample magnetometer. Subsequently, this novel copper (II) nanomagnetic complex was evaluated as an efficient, reusable, and novel catalyst for the formation of C-N bonds via the Ullmann coupling reaction of aryl halides and nitrogen-containing compounds. The influence of this novel TCTCl (DiPrAEA)2 ligand on the reactivity and stability of the nanomagnetic copper complex was visible in the Ullmann reaction, which resulted in rapid reaction times and excellent yields, and seven times reusability.

Two novel complexes were synthesized by the reaction of benzothiazol-pyrimidin-2-ylidene ligand (BTP) with Pd (II) and Fe (III) ions. A variety of various spectral and analytical methods (infrared, ¹H/NMR, ¹³C/NMR, electronic spectra, CHN analyses, mass spectra, thermogravimetric analysis, and magnetic susceptibility) were used to characterize the investigated BTP ligand and its complexes. Correlation of experimental results with density functional theory calculation proves that the geometry of BTP-Fe complex is octahedral, whereas BTP-Pd complex is square planner. The catalytic effectiveness of BTP complexes were tested for three-component condensation process under moderate and environmentally friendly reaction conditions. Moreover, the effects of different Lewis acid, basic, and ionic liquid catalysts, as well as solvent and catalyst dose on the catalytic reaction were investigated. Both catalysts demonstrated strong catalytic capability in the carefully regulated ideal reaction circumstances. Heterogeneous catalyst BTP-Pd exhibited superior catalytic performance compared to homogeneous catalyst BTP-Fe. All products were obtained in high TOF (turnover frequency) numbers in the presence of these catalysts, which indicate the high efficiency of these catalysts in the synthesis of dihydro-7H-5-thia-hexaaza-s-indacen-6-one derivatives. Moreover, the two catalysts' recycling and reusability in reactions were also investigated. Heterogeneous BTP-Pd catalyst could be reused up to seven times with high efficiency, but the homogeneous catalyst (BTP-Fe) could only be recycled up to four times. Furthermore, the mechanism of catalytic reaction was suggested and supported by DFT calculation. The simplicity, safety, stability, use of commercially available catalysts, quick reaction times, and excellent yields make it promising for future industrial use.

Two chelating N-heterocyclic carbene (NHC) palladium complexes 3a-b containing N-(3-bromopropyl)-N′-thioether difunctionalized imidazol-2-ylidene were synthesized by direct metalation of the precursor imidazolium salts and characterized by NMR and HR-MS. The molecular structure of 3a has been further characterized unambiguously by X-ray single crystal analysis. The subsequent substitution reaction with amine-functionalized magnetic nanoparticles (MNPs-NH₂) afforded two highly active, stable, and recyclable magnetic nanoparticle supported NHC palladium complexes, MNPs-NHC-Pd I-II, which were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), inductively coupled plasma optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The MNPs-NHC-Pd complexes exhibited high catalytic activity in the Suzuki–Miyaura cross-coupling reaction of aryl bromides with arylboronic acids, as well as in the reduction of toxic 4-nitrophenol (4-NP) under mild conditions. The recycling experiment of MNPs-NHC-Pd I in the Suzuki–Miyaura cross-coupling reaction between 4-bromoanisole and phenylboronic acid showed that the yield of 4-methoxybiphenyl remained high at 88% within 0.5 h at 60 °C, indicating that the catalytic activity was well maintained for at least 10 cycles.

Surfactant-assisted synthesis of photocatalysts for water treatment has received extensive attention from researchers. In this paper, a novel and efficient BiOBr/graphene oxide (BiOBr/GO) photocatalyst assisted by sodium dodecyl sulfate (SDS) was synthesized by a simple solvothermal method. Compared with use of other surfactants, like polyvinylpyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB), BiOBr/GO (SDS) shows outstanding photocatalytic degradation activity under optimal conditions: The degradation rate constants of BiOBr/GO (SDS) for oxytetracycline (OTC), tetracycline hydrochloride (TCH), brilliant blue (BB), and Rhodamine B (RhB) are 0.073, 0.057, 0.166, and 0.626 min⁻¹, which are 2.8, 1.8, 9, and 1.5 times larger than pure BiOBr, respectively. In addition, after five cycles, BiOBr/GO (SDS) exhibits superior cycling stability. The enhanced photocatalytic performance can benefit from the introduction of SDS and GO. With the assistance of SDS in the preparation process, BiOBr/GO (SDS) nanosheets have good adsorption performance and dispersion effect, which is favorable for raising their specific surface area. Meanwhile, the electron capture effect of GO improves the transfer and separation efficiency of photogenerated carriers. Moreover, the possible degradation pathway for TCH is identified through liquid chromatography–mass spectrometry (LC–MS). This research can become a valuable reference for synthesizing photocatalysts with visible light response to degrading organic pollutants such as antibiotics and dyes.