Transition Metal Chemistry最新文献

One pot reaction mixture of Salicylaldehyde, furfural amine, and further addition of cis-[MoO₂(acac)₂] in ethanol yielded cis-[MoO₂L₂] type complex, cis-[MoO₂(Sal-Fa)₂], where Sal-Fa stands for the deprotonated condensate of salicylaldehyde and furfural amine, (2-[(E)-{[(oxolan-2-yl)methyl]imino}methyl]phenolate). The yellow-colored crystals obtained by slow evaporation of the reaction mixture were used to collect single-crystal X-ray diffraction data, and the structure of the complex was elucidated. Further, the complex, cis-[MoO₂(Sal-Fa)₂], was characterized by various spectroscopic techniques such as FTIR, UV-visible, ¹H-NMR, and ¹³C-NMR. The results were consistent with the molecular structure determined by single-crystal X-ray diffraction data. The cyclic voltammogram of the complex shows an irreversible one-electron reduction response at − 1025 mV for the Mo(VI) to Mo(V) reduction. cis-[MoO₂(Sal-Fa)₂] shows antibacterial activity against Staphylococcus sp (Gram-positive bacteria) and Klebsiella (Gram-negative bacteria). The minimum inhibitory concentrations were 5 mg/mL and 7.5 mg/mL, respectively. Furthermore, molecular docking studies against Glucosamine-6-phosphate synthase (GlcN-6-P), a crucial bacterial and fungal enzyme target, showed an excellent binding free energy of -9.02 kcal/mol, where the standard antibiotic streptomycin binding free energy is -5.72 kcal/mol. These findings highlight the potential of furan-based Schiff-base molybdenum complexes as scaffolds for developing new therapeutic agents with enhanced biological activity.

Two new Ag(I) complexes, [Ag₃(Me-bba)₃(trimesate)]·3C₂H₅OH (1) [Ag₂(Me-bba)₂(terephthalate)]·2H₂O (2) (Me-bba = 1,3-bis[(N-methylbenzimidazole)methylene]-2-aniline), were synthesized and characterized. Structural analysis shows that the two complexes are trinuclear fan-shaped and binuclear centrosymmetric structures, respectively. The electrochemical sensing properties of two composite electrodes (CE-1 and CE-2) prepared from two multinuclear Ag(I) complexes were investigated using chronoamperometry (CA) in 0.2 M PBS (pH = 6) for hydrogen peroxide. The results manifest that the two composite electrodes (CE-1 and CE-2) exhibit good linear responses to hydrogen peroxide in the concentration ranges of 0.5 µM ~ 50 µM and 0.1 mM ~ 4 mM. The CE-1 and CE-2 show high sensitivities of 188.11 and 4.07 µA·mM⁻¹·cm⁻², and low detection limits (S/N = 3) of 0.21 and 0.38 µM, respectively. The sensing performance of CE-1 is better than that of CE-2, because there are more active centers and greater deformability of Ag(I) in complex 1. Moreover, the two sensors have excellent stability, selectivity, fast response time (≤ 3 s), and the recoveries of CE-1 in the actual sample detection are 98.6% to 104.0%.

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Two new Ag(I) complexes were synthesized and characterized. The electrochemical sensing properties of two composite electrodes (CE-1 and CE-2) prepared from two multinuclear Ag(I) complexes were investigated using chronoamperometry (CA) in 0.2 M PBS (pH = 6) for hydrogen peroxide. The two composite electrodes demonstrated excellent electrochemical sensing of performance for H₂O₂ with the high sensitivity of 188.11 (CE-1) and 4.07 (CE-2) µA·mM^− 1·cm^− 2. Moreover, the two sensors have excellent stability, selectivity, fast response time (≤ 3 s), and the recoveries of CE-1 in the actual sample detection are 98.6% to 104.0%.

The growing global demand for lithium, driven by its pivotal role in lithium-ion batteries (LIBs) for electric vehicles and renewable energy storage, necessitates the development of efficient and sustainable recovery strategies. This study introduces a systematic optimisation approach for synthesising titanium-based lithium-ion sieves (Li₂TiO₃/LTO) via a solid-state reaction using TiO₂ and Li₂CO₃ as precursors, followed by delithiation to produce H₂TiO₃ (HTO). The effects of calcination temperature, heating rate, and Li/Ti molar ratio on structural and functional properties were systematically investigated. Optimal synthesis conditions (Li/Ti ratio 2.0, 850 °C, 9 °C/min) yielded an adsorption capacity of ~ 65 mg/g. Advanced characterisation (XRD, SEM, FTIR, ICP-OES, PSA) confirmed phase purity, nanoscale morphology, and successful delithiation. Kinetic modelling identified the three-dimensional diffusion (Jander) model as most appropriate, with activation energy and pre-exponential factors increasing at higher Li/Ti ratios. Reusability testing demonstrated that HTO outperformed Mn-based sieves, maintaining 55 mg/g after 10 cycles with a Ti dissolution rate of 2.5%. An economic assessment further highlighted the lower operational cost and environmental burden of Ti-based sieves compared to Mn-based alternatives. Overall, the optimised HTO exhibits high adsorption capacity, superior cyclic stability, and economic feasibility, positioning it as a strong candidate for scalable and sustainable lithium recovery from brine.

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We report a comprehensive density functional theory (DFT) study of transition-metal (TM) doped (CdSe)₁₃ nanoclusters, focusing on structural stability, bonding, electronic structure, and magnetism. Substitution of Cd by Mn, Fe, Co, Ni, Cu, Zn, and Hg is examined at two distinct sites. Substitution energies and vibrational frequency analyses confirm that all doped clusters are stable minima, while short molecular dynamics simulations at 300 K verify their dynamical robustness. Bond length and Mayer bond order analyses reveal a systematic progression from ionic (Mn) to covalent (Co, Ni, Cu) bonding, with Zn and Hg behaving as nearly inert d¹⁰ dopants. Hirshfeld charges and magnetic moments corroborate this classification, showing strong correlation between charge transfer, bonding covalency, and magnetic spin states. Electronic analysis demonstrates that TM substitution generally narrows the HOMO–LUMO gap relative to pristine (CdSe)₁₃ (~ 2.3 eV), enhancing conductivity via LUMO stabilization. Mn and Fe retain relatively large gaps (~ 1.2 eV), Co and Ni reduce gaps below 1 eV, and Cu produces the most dramatic narrowing (0.41 eV, Type A). Zn and Hg preserve host-like gaps (> 2 eV), consistent with minimal d–p hybridization. Partial density of states (PDOS) confirm that gap modulation arises from dopant d-orbital participation. These findings establish clear structure–property relationships in TM-doped CdSe nanoclusters, with implications for their design in optoelectronic and spintronic applications.

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To address the challenge of antibiotic residue remediation, this study employed a hydrothermal method to in-situ construct a bimetallic indium/gallium-based MIL-68 heterostructure on the surface of two-dimensional montmorillonite (MMT). By integrating metal node electronic structure regulation with interface engineering strategies, it provides a feasible approach to improve the low charge carrier separation efficiency in metal-organic framework (MOFs) materials. Experimental results demonstrate that when the MMT loading is 20%, the composite material exhibits obvious enhanced photocatalytic performance for the degradation of 40 mg/L tetracycline solution, with a degradation rate of up to 97% within 60 min using 10 mg of catalyst. This improvement is attributed to the synergistic effect of In/Ga bimetals and the interface charge transfer channels of the MMT 2D matrix, which together induce a Z-type charge carrier migration mechanism, enhancing the separation efficiency of photo-induced electron-hole pairs. After four cycles, the MIL-68(In/Ga)/MMT composite showed good cycling stability and demonstrated broad-spectrum degradation capability, achieving degradation rates of 99% and 79% for rhodamine B and methyl orange, respectively. This composite material shows good photocatalytic performance in dye degradation, providing new research insights for the field of photocatalytic degradation of pollutants.

In this study, a novel thiourea derivative, TH3, was synthesized and structurally characterized using FTIR and ¹H NMR spectroscopy. The fluorescence sensing behavior of TH3 was explored against a series of metal ions. Among all tested ions, TH3 exhibited a distinct and highly selective “turn-on” fluorescence response exclusively toward Hg²⁺ ions. This fluorescence enhancement is attributed to the formation of a stable TH3-Hg²⁺ complex. The Job’s plot confirmed a 1:2 binding stoichiometry between TH3 and Hg²⁺. The limit of detection (LOD) and limit of quantification (LOQ) for TH3 were calculated to be 0.0093 ppm (0.0465 µM) and 0.031 ppm, respectively., indicating a high sensitivity suitable for trace-level detection. The practical applicability of TH3 was validated by analyzing various environmental water samples (pond water, drinking water, lake water, and river water) and biological samples (human urine and blood serum), achieving excellent recovery rates ranging from 91.0 ± 0.49% to 102.2 ± 0.75%, demonstrating its reliability and robustness in complex matrices. Furthermore, the antimicrobial activity of both the free TH3 and its Hg²⁺ complex was evaluated, with both showing significant antimicrobial efficacy against tested bacterial and fungal strains.

Malaria remains a global health challenge due to the emergence and spread of drug-resistant strains, highlighting the urgent need for the development of new treatments. Gold(I) hybrids, [AuCQPQ]⁺ (Auhyb1) and [AuAQPQ]⁺ (Auhyb2), incorporating chloroquine (CQ), amodiaquine (AQ), and primaquine (PQ), exhibited potent antiplasmodial activity by disrupting hemozoin formation, likely through ferriheme binding. To elucidate these interactions, we employed molecular dynamics and DFT calculations to assess binding conformations and energies. Results indicate that protonated Auhyb1 forms a clamp-type structure around ferriheme, stabilizing the formed complex via strong H-bonds and π–π stacking. Such interactions reflect a decrease in enthalpy, while the gold ion presence induces an entropy effect also favoring the association with ferriheme. Auhyb2, in contrast, interacts through AQ’s alcohol group coordination to iron, alongside H-bonding and π–π interactions, forming a stable alkoxide metal complex. These molecular interactions could enhance the antimalarial efficacy of conventional low-cost aminoquinoline drugs contributing to disrupt hemozoin crystallization in malaria’s parasite.

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A series of novel zinc(II) halide complexes with the versatile twisted, non-classical scorpionate ligand, bis((5-methyl-1,3,4-thiadiazol-2-yl)thio)methane (CH₂(S-tdzMe)₂) (1), have been synthesized and characterized. The ligand (1) reacts with ZnX₂ (X = Br, Cl, I) in a 1:1 molar ratio to afford the complexes [Zn(CH₂(S-tdzMe)₂)X₂] (X = I (2), Br (3), Cl (4)). These complexes, along with the ligand, were characterized by elemental analysis, FT-IR, HRMS, UV–Vis, and multinuclear NMR spectroscopy. Single crystal X-ray diffraction studies of the ligand (1) and complex (4) revealed a tetrahedral geometry around the zinc(II) ion with the ligand coordinating in a κ2N-fashion. Preliminary interaction studies with bovine serum albumin (BSA) using fluorescence spectroscopy suggest potential protein-binding capability.

Developing an efficient, affordable and long-lasting electrocatalyst is a primary focus of ongoing investigations for electrochemical water splitting. Herein, MoO₃@rGO nanohybrid was fabricated via hydrothermal technique and utilized as catalyst for oxygen evolution reaction (OER) with Ni foam (NF) serving as a conductive substrate. Because of their vigorous electrical features and cooperative outcome, the MoO₃-based composite is more suitable for water oxidation reaction. A range of analytical tools was implemented to assess the crystallinity, morphology, surface area (SA) and thermal durability of the fabricated substances. The electrochemical studies in alkaline media exhibited that MoO₃@rGO nanohybrid has remarkable Tafel slope (38 mV/dec) and a lower overpotential (η) of 196 mV at current density (C_d) of 10 mA/cm² for OER. Moreover, the fabricated nanohybrid possesses remarkable stability after 3000th cycles. All these remarkable outcomes confirmed that the generated nanohybrid is a promising electrocatalyst with effectively regulated ordered structures for increasing OER activity.