Applied Organometallic Chemistry最新文献

In this work, a set of Pyridine Infused Schiff bases 3(a-b) has been synthesised and characterised using mass spectrometry, ¹³C NMR and ¹H NMR spectroscopy. Exploiting the X-ray crystallography, synthesised molecules 3a and 3b have been investigated. Compound 3a demonstrated remarkable sensitivity and selectivity towards Zn²⁺ ions, with minimal interference from other metals ions, as validated by UV–Vis and fluorescence spectroscopy. According to the job's plot, compound 3a links to Zn²⁺ in a 1:1 ratio. Through the analysis of Stern–Volmer plot and B-H plot, the binding constants were determined to be 8.17 × 10⁸ M⁻¹ and 5.70 × 10⁴ M⁻¹, and the Limit of detection (LOD) values were 0.035 nm and 5.912 μM, correspondingly. The synthesised compounds 3(a-b) were subjected to in vitro testing to assess their antibacterial activity against bacteria such as B. subtilis, S. aureus and Pseudomonas yielding positive findings. Additionally, the in vitro anticancer investigation was carried out, and impact of 3a was examined. Furthermore, compound 3a was docked to the cervical cancer protein, B. subtilis, S. aureus, and Pseudomonas, exhibiting encouraging binding energies of −8.33, −8.56, −9.82, and −8.65 Kcal/mol, respectively. The insights from both docking assessments as well as in vitro evaluations propose that compound 3a holds a great deal of promise as an antibacterial and anticancer drug. Additionally, 3a was effective in detecting Zn²⁺ ions in both real-world and pharmaceutical samples.

A palladium-catalyzed β-carbonyl alkylation of α-imino esters with readily available allylic/propargyl alcohols has been developed, enabling efficient synthesis of structurally diverse δ-carbonyl-α-amino acid esters and carbonyl-containing pyrrolidine derivatives. Mechanistic studies indicate that the reaction proceeds via a dehydrogenation-Michael addition or [3 + 2] cyclization pathway. This method offers an atom-economical and operationally straightforward strategy for the synthesis of highly functionalized Δ(1)-pyrrolines and pyrrolidines.

In this paper, a novel synthetic route is presented for the production of 99.99% high-purity anhydrous rare earth fluoride. First, organic system was used to produce high-purity diphenylpropanedione salt with hydrated rare earth salt as raw material through complex reaction, followed by recrystallization, and high-temperature vacuum drying to remove water of crystallization. Then, the resulting complex salt was reacted with ammonium hydride fluoride to prepare high-purity anhydrous rare earth fluoride. This method avoids the challenges associated with traditional dry methods, such as harsh reaction conditions and the easy introduction of impurities, as well as the high oxygen content and filtration difficulties of wet methods. The purity, oxygen content, and composition of the prepared rare earth fluoride products were analyzed using thermal analyzers, scanning electron microscopy, X-ray diffraction, inductively coupled plasma mass spectrometry, and an oxygen analyzer. The results demonstrated that this method produces rare earth fluoride with high purity, anhydrous properties, low oxygen content, and excellent crystallinity. This approach represents a green, efficient, and innovative preparation method for rare earth fluoride and offers a new pathway for the production of high-purity rare earth fluoride compounds.

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.