Applied Organometallic Chemistry最新文献

A new Schiff base (3) was successfully synthesized and its purity was verified through NMR, FT-IR and mass spectrometry analyses. The probe 3 sensing was performed with different metal ions demonstrated selective detection of Ni (II), In (III), and V (III) UV–visible spectrophotometric, also the titration plots helped to determine respective limits of detection (LOD) of 3.0, 0.28, and 0.37 μM respectively. Stoichiometric analysis revealed binding ratios of 1:1 for Ni (II) and V (III) and 2:1 for In (III) against probe 3. Minimal changes in absorbance indicated negligible interference from other metal ions. Molecular docking studies against biologically significant protein 4UUN identified the TRPV1 ion channel, involved in pain and heat sensation, showing the highest binding affinity with a binding energy value −8.87 kcal/mol.

Three new high-dimensional MOFs, {[Cd₃(L)₂(H₂O)₄]·5.5H₂O}_n (1), {[Co₂(L)(H₂O)₂(OH)]·(CH₃CN)}_n (2), {[Mn(H₂L)₂]}_n (3) were constructed using Cd(II)/Co(II)/Mn(II) metal ions and pyridine tricarboxylate ligand 3-(3,5-dicarboxyphenyl)-4-carboxypyridine (H₃L) under solvothermal conditions. Based on the diversity of ligand coordination patterns, the complexes show unique structures and properties. Complexes 1–2 are new three-dimensional frameworks based on diverse dinuclear/tetranuclear metal clusters, respectively. Complex 1 contains a one-dimensional cylindrical channel in its structure, which has good thermal stability. It not only has excellent solid-state fluorescence properties at room temperature, but also can highly sensitively identify the Cr₂O₇²⁻, CrO₄²⁻, and Fe³⁺ in aqueous solutions with low detection limits (5.9 × 10⁻⁴ M, 9.9 × 10⁻⁴ M and 3.7 × 10⁻⁴ M). In addition, the fluorescence quenching mechanism of specific ions in aqueous solution was discussed in depth. Complex 3 is a two-dimensional layered structure with a unique Mn-O metal oxygen chains. At the same time, the magnetic studies of complexes 2–3 confirmed the existence of antiferromagnetic interactions between adjacent metal ions within the framework.

This study describes the synthesis and characterization of a novel tripodal ligand, tris(5-phenylethyliminopyrrol-2-ylmethyl)amine (H₃tpa^PEA; 1), derived from a known scaffold. The ligand was synthesized via Vilsmeier–Haack formylation followed by condensation, with NMR and X-ray crystallography confirming its C₃-symmetric structure. Two copper complexes were prepared: a tricopper cluster [tpa^PEACu₃(μ₃-SO₄)(μ₃-OH)] (2) with rare μ₃-SO₄ and μ₃-OH bridging ligands, and [tpa^PEA₂Cu₃] (3) featuring tetracoordinated copper centers. Structural analyses revealed unique geometries and coordination environments, suggesting enhanced reactivity potential. Both complexes catalyzed CuAAC azide–alkyne cycloaddition reactions, with complex 3 demonstrating superior efficiency, achieving complete conversion in 5 min due to its accessible coordination sites. This research enhances understanding of multinuclear copper complex structures and their catalytic functions, emphasizing the crucial influence of ligand design and bridging ligands in maximizing catalytic efficiency.

Several racemic zirconium complexes 1–8 featuring [NOON]-type ligands were synthesized through alkane elimination reactions between Zr(CH₂SiMe₃)₄ and the respective new proligands in toluene. Spectral and elemental analyses were used to characterize these complexes, which demonstrated good performance in rac-lactide polymerization. All complexes displayed comparable catalytic activity, with 5 exhibiting the highest activity (TOF = 58.7 h⁻¹) and 8 yielding polylactide with the highest molecular weight (M_n = 8.6 × 10⁴ g/mol). Notably, these systems outperform existing zirconium complexes bearing [NSSN]-type, [OSSO]-type, and ethylene-bridged [ONSO]-type ligands, as well as phosphasalen Ti/Zr complexes, under analogous polymerization conditions. To enhance the stereoselectivity of these systems, four co-agents—pyridine, 2,2′-bipyridine, DME, and TMEDA—were evaluated. TMEDA was found to significantly improve the stereocontrol of all complexes, with complex 2 showing the highest stereoregularity (P_m = 0.72).

The geometric structures and electronic properties of three experimentally reported anticancer Pt (II), Au (III), and Cu (II) complexes (named complexes 1–3) as well as the interactions of these complexes with biological target molecules have been explored in detail by density functional theory (DFT) calculations. Significant differences in the polarity of M-Cl (M = Pt, Au, and Cu) bonds and the nucleophilic reactivity of metal centers were revealed for these complexes. Further research shows that the differences in the hydrolysis and the ligand exchange reactions with biological targets of these complexes are the main reasons for their different antitumor activities. Based on these findings, four novel complexes 4–7 have been rationally designed by replacing the Cu (II) center of 3 with Ni (II), Zn (II), Pd (II), and Fe (II) ions for the first time. Therein, the obtained Zn (II)–centered complex 5 is predicted to exhibit the highest similarity to complex 3. This study not only provides a profound theoretical insight into the activity difference of the reported metal complexes from molecular level but also proposes an effective strategy to design new anticancer drugs.

An eco-friendly, visible-light-driven synthesis of benzamides from readily accessible benzonitriles is reported under heterogeneous conditions. A carbon-rich material, such as polyhexahydrotriazine (PHT), graphene oxide (GO), graphitic nitride (g-C₃N₄)or carbon black, was used as a novel support to stabilise silver nanoparticles (NPs). These silver NPs show remarkable catalytic activity in the hydration of nitriles under visible light irradiation (white light, 9 W). Furthermore, silver NPs stabilised by a triazine moiety exhibit better performance than other supported silver systems, including graphene oxide and carbon black. Their stability and heterogeneous nature as catalysts have been demonstrated through three cycles of recycling in the synthesis of benzamides. This approach utilises mild visible light and a recyclable catalyst that efficiently converts benzonitriles to amides in excellent yields. This work provides a sustainable approach to amide synthesis. Density functional theory (DFT) calculations further indicate that the binding energy of 4-bromobenzonitrile (BCN) to Ag@C₃N₄ is −31.50 kcal/mol. Further triphenyl phosphine poisoning test confirms the heterogeneous nature of our catalyst under visible light.

A series of Fe^III complexes [Fe(5-Br-3-MeO-sal₂Trien)]Y·Z (Y = NO₃⁻, Z = 0.5CH₃OH·CH₃CN (1); Y = NO₃⁻ (2); Y = ClO₄⁻ (3)) have been prepared. Complexes 1 and 2 exhibit analogous crystal packing architectures with two distinct iron centers, labeled Fe1 and Fe2. The Fe1 sites form dimers encapsulated within a hexagonal framework constructed by Fe2 centers. Thermal expansion of the Fe2 framework upon heating creates sufficient space to facilitate the spin transition of Fe1. Both complexes display similar one-step gradual spin crossover behavior, with transition temperatures (T_c) of 142 K for 1 and 186 K for 2, respectively. In contrast, complex 3 incorporates four crystallographically independent Fe centers. Its overly compact packing geometry sterically hinders spin-state switching, resulting a partial low-spin state over the entire tested temperature range.

In this study, we used Lobelia chinensis leaves to describe biogenically supported iron nanoparticles. The leaf of Lobelia chinensis was utilized as an excellent stabilizer for the iron nanoparticles that were synthesized. The as-synthesized Fe NPs@Lobelia chinensis were physicochemically characterized using FE-SEM, FT-IR, XRD, EDX, and UV–Vis. The DPPH technique was used to assess the antioxidant efficacy of nanoparticles. Based on the IC₅₀ value, the antioxidant activity of the Fe NPs@Lobelia chinensis was significant. Because of their antioxidant qualities, recent nanoparticles seem to have an antihuman endometrial carcinoma potential. Fe NPs@Lobelia chinensis that was biologically produced was evaluated for their anti-endometrial cancer properties against endometrial cancer cells. By using the MTT assay, the anti-endometrial cancer characteristics of the Fe NPs@Lobelia chinensis could effectively eliminate HEC-1-B cancer cells. In contrast to their corresponding control, Fe NPs@Lobelia chinensis prevented colony formation. Crucially, the molecular pathway analysis of cells exposed to Fe NPs@Lobelia chinensis revealed that the particles increased the expression of p53 while suppressing the production of phosphorylated and total STAT3 in cells. This suggests that STAT3 and p53 are the primary players behind the medical events that the extract triggered in endometrial carcinoma cells.

Given the adverse effects of conventional chemotherapeutic agents, natural compounds and biocompatible materials have garnered growing interest in cancer therapy. Our previous research demonstrated that zinc oxide nanoparticles (ZnO NPs), synthesized through an ultrasound-mediated green method using coffee leaves, functioned as effective nanocarriers for the controlled release of mangiferin (MGF). Here, we investigated the anticancer activity of MGF, ZnO NPs, and MGF-loaded ZnO NPs (MGF-ZnO NPs) on HepG2 and Caco-2 cells, along with their underlying anticancer mechanisms. We found that both ZnO NPs and MGF-ZnO NPs significantly reduced cell viability and increased the extracellular to intracellular pH ratio (pHe/pHi) and reactive oxygen species levels in HepG2 and Caco-2 cells. MGF-ZnO NPs further induced notable morphological changes and enhanced cell membrane permeability, chromatin condensation, and nuclear lysis. Additionally, both ZnO NPs and MGF-ZnO NPs increased the overall apoptotic rate in cancer cells, with MGF enhancing the cytotoxic effects of MGF-ZnO NPs. Molecular docking analysis revealed that MGF-ZnO NPs may disrupt cell membrane biogenesis by inhibiting the biological activity of choline/ethanolamine phosphotransferase 1 (CEPT1), an enzyme involved in phospholipid synthesis, through hydrogen bonding and hydrophobic interactions. Additionally, MGF-ZnO NPs also exhibited strong binding affinity to DNA bases through hydrogen bonds (DC15(B) and DG12(A)) and hydrophobic interactions (DC23(B), DG22(B), DA18(B), DA17(B), and others), potentially compromising DNA function. This study suggests that loading ZnO NPs with MGF is a promising approach to enhance cancer therapy and underscores the complex mechanisms involved in nanotherapeutic action.

Green hydrogen serves as a crucial renewable energy source driving the transition of energy structures and advancing sustainable development. Photocatalytic technology represents one of the prominent approaches for green hydrogen production. Compared to traditional semiconductors, noble metal single-atom catalysts (SACs) have emerged as promising photocatalysts due to their high atomic utilization efficiency and superior catalytic activity. In this work, Pt and Pd single atoms were separately anchored onto oxygen vacancies (Vo) on the TiO₂ surface via a facile photodeposition method, yielding Pt or Pd monometallic single-atom loaded catalysts (Pt SAs/Vo-TiO₂ and Pd SAs/Vo-TiO₂). The optimal photodeposition time was investigated. Results demonstrate that the hydrogen evolution rate of Pt SAs/Vo-TiO₂ reached 2375.76 μmol h⁻¹ g_cat.⁻¹, while that of Pd SAs/Vo-TiO₂ achieved 1875.72 μmol h⁻¹ g_cat.⁻¹. These values are 76.5-fold and 60.4-fold higher than that of pristine TiO₂, respectively. Density functional theory (DFT) calculations reveal that the introduction of single atoms reduces the band gap of the catalyst, consistent with the experimental findings. This study provides optimal parameters for synthesizing efficient single-atom catalysts.