New Journal of Chemistry最新文献

A dopamine-derived carbon-coated selenide composite (NiFeMnCuZn)Co₂Se₄@C (HESe@C) was synthesized by a solvothermal method followed by carbonisation and evaluated as an anode material for lithium-ion batteries (LIBs). Structural characterization shows that HESe@C possesses a dominant crystalline selenide phase, a thin carbon coating layer, and a porous nanocluster morphology. Electrochemical measurements indicate that HESe@C delivers an initial discharge capacity of 880 mAh g⁻¹ at 0.1 A g⁻¹ and retains 966 mAh g⁻¹ after 100 cycles. In addition, a reversible capacity of 380 mAh g⁻¹ is maintained at 5.0 A g⁻¹, which is higher than that of NiCo₂Se₄@C under the same conditions. Electrochemical impedance spectroscopy reveals a lower charge-transfer resistance for HESe@C. Kinetic analysis based on scan-rate-dependent cyclic voltammetry shows that the pseudocapacitance contribution reaches 94.2% at 1.0 mV s⁻¹. The improved electrochemical performance is likely related to the combined effects of multicomponent composition, carbon coating, and porous structure, which may facilitate charge transfer and ion transport. These results indicate that HESe@C is a promising selenide and carbon composite anode for LIBs.

Short- to middle-length aliphatic acids have significant applications in high quality lubricant synthesis. The present work introduces a Lewis acid (LA) improved aerobic oxidation of short- to middle-length aliphatic aldehydes to the corresponding acids by the Mn(acac)₂ catalyst with high efficiency. It was found that adding a modest LA such as Ca(OTf)₂ could substantially improve Mn(acac)₂-catalyzed aldehyde oxidations to the corresponding acids with yields up to 97%. Quenching experiments with 1,4-benzoquinone indicated that the superoxide radical plays a crucial role in catalysis. The trapping experiments with methyl p-tolyl sulfide disclosed that the content of peroxide and peracid was very limited in the reaction mixtures, and monitoring the temperature and pressure of the oxidation also showed that the reaction proceeded smoothly without obvious temperature and pressure changes, highlighting the promising advantages of this Mn(acac)₂/Ca(OTf)₂ catalysis in its practical applications for the middle-length aliphatic acid production from the corresponding aldehydes.

A series of four novel lanthanide complexes was obtained: [Ln(3-MBA)₃(5,5′-DM-2,2′-bipy)]₂·(H₂O) (Ln = Sm (1), Pr (2), Nd (3)) and [La(3-MBA)₄(5,5′-DM-2,2′-bipy)]₂ (4) (3-MBA = 3-methylbenzoate; 5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′-bipyridine). Single-crystal X-ray diffraction structural studies established that complexes 1–3 crystallize in the triclinic system with the space group P and the metal center adopts a nine coordinate contiquration. In contrast, complex 4 crystallizes in the monoclinic with space group P2₁/n. Detailed crystallographic data indicate that in complexes 1–3, the 3-MBA ligands bind to the Ln³⁺ through diverse coordination modes, specifically exhibiting chelating bidentate, bridging bidentate, and bridging tridentate modes. Surprisingly, there are eight 3-MBA ligands in the structure of complex 4, which adopt monodentate, bridging bidentate, and bridging tridentate coordination modes, which is very rare in the study of similar complex structures. A suite of complementary techniques, including elemental analysis, IR and Raman spectroscopy, and PXRD, was employed to characterize the complexes. The thermal decomposition behavior of all four complexes was studied using a coupled simultaneous TG-DSC/FTIR/MS system. The results indicate that the complexes initially lose crystal water or neutral ligand molecules at relatively low temperatures, followed by the stepwise elimination of organic carboxylate ligands at higher temperatures. The final thermal decomposition products were identified as the corresponding lanthanide metal oxides. Additionally, the fluorescence spectrum of complex 1 was measured. DFT calculations reveal an energy transfer mechanism between the triplet states of both ligands and the Sm³⁺.

Developing green and controllable routes for copper nanoparticle synthesis remains important for expanding their functional applications. Herein, a non-electrochemical one-pot chemical reduction strategy was developed for synthesizing copper nanoparticles (Cu NPs) in ethaline deep eutectic solvent (DES). The phase evolution of copper species was systematically investigated by regulating reaction temperature and time. The results revealed a stepwise transformation pathway from soluble [CuCl₄]²⁻ complexes to an amorphous Cu^II–O/OH–H₂O precursor, a crystalline Cu₂O intermediate, and finally metallic Cu⁰ nanoparticles. This transformation was driven by the combined effects of KOH-induced coordination perturbation, NaH₂PO₂-mediated stepwise reduction, and ethaline-regulated interfacial confinement. Under the optimized condition of 383 K for 6 h, high-purity (>99 wt%), highly crystalline, quasi-spherical Cu NPs with a median particle size of 94.6 nm were obtained without external capping agents. The optimized Cu NPs exhibited stronger antibacterial activity than commercial ultrafine Cu powder against Staphylococcus aureus and Escherichia coli under agar-dilution conditions. At 0.5 g L⁻¹ after 12 h incubation, no visible colony formation was observed for the Cu NP-treated groups. Concentration-dependent antibacterial tests, FESEM observations, and ICP-MS analysis further suggest that the antibacterial activity is associated with nanoscale particle–bacteria interactions, bacterial envelope damage, and enhanced availability of soluble copper species. This work provides mechanistic insight into DES-mediated phase-directed Cu nanoparticle formation and offers a practical route for preparing functional antibacterial copper nanomaterials.

CuO–ZnO is a key catalyst widely used in catalytic processes such as dehydrogenation and hydrogenation. Hence, revealing the impact of H₂O and H₂ on the stability of CuO–ZnO catalysts is of critical importance. In this work, a CuO–ZnO/SiO₂ catalyst with highly dispersed CuO–ZnO interface active sites was synthesized, and the structure–activity relationship and deactivation mechanism were systematically investigated using a model reaction (the cyclodehydrogenation of 1-amino-2-propanol to 2,5-dimethylpyrazine) that simultaneously generates H₂O and H₂. Under optimized reaction conditions (250 °C, space velocity: 1.5 h⁻¹, and N₂ flow rate: 8 mL min⁻¹), a 2,5-dimethylpyrazine yield of 68.1% was achieved over the CuO–ZnO/SiO₂ catalyst. The investigation into the deactivation mechanism reveals that Cu species agglomeration and carbon deposition are the primary reasons for the decline in activity. The roles of H₂ and H₂O in catalyst stability were found to be different: H₂ suppressed the aggregation of metallic Cu⁰, while H₂O enhanced stability by suppressing the formation of carbon deposits. Based on the understanding of the deactivation mechanism, catalyst regeneration was performed through air calcination, recovering the 2,5-dimethylpyrazine yield to 88.1% of the initial value. Overall, this work reveals the deactivation pathways and stabilization mechanisms of CuO–ZnO/SiO₂ catalysts under reactive atmospheres containing H₂ and H₂O, offering theoretical guidance for industrial application and design of a highly stable CuO–ZnO catalyst.

This study systematically investigates the performance of V₂CBi₂ as an anode for alkali metal-ion (Li/Na/K) batteries using first-principles methods and explores the effect of O-doped V₂CBi₂ on its performance as an anode for ion batteries. We systematically assessed its structural stability, electronic properties, adsorption characteristics, diffusion barriers, open-circuit voltage (OCV), and volumetric capacity. The results show that V₂CBi₂ maintains excellent thermal stability under both room temperature (300 K) and high-temperature (500 K) conditions. In addition, V₂CBi₂ itself exhibits excellent electrical conductivity, and its adsorption energies for Li/Na/K range from −1.55 to −2.05 eV, which is conducive to the formation of stable adsorption configurations. The diffusion barriers of Li/Na/K ions on V₂CBi₂ range from 0.07 to 0.15 eV, and the extremely low diffusion barriers are conducive to improving battery rate performance. The theoretical capacities of V₂CBi₂ for Li, Na, and K ions are 403.11 mAh g⁻¹, 251.94 mAh g⁻¹, and 100.78 mAh g⁻¹, respectively, corresponding to volumetric capacities of 3777.14 mAh cm⁻³, 2356.46 mAh cm⁻³, and 944.31 mAh cm⁻³. The excellent volumetric capacity indicates that V₂CBi₂ can release more energy within the same volume. The OCVs of V₂CBi₂ for Li, Na, and K ions are 0.25 V, 0.48 V, and 2.78 V, respectively. The low volumetric capacity (944.31 mAh cm⁻³ for K) and a high OCV (2.78 V for K) indicate that V₂CBi₂ is unsuitable as an anode for K-ion batteries. Under oxygen-doping conditions, V₂CBi₂ still maintains conductivity, but the diffusion barrier increases significantly. Therefore, oxidation of V₂CBi₂ should be minimized during experimental preparation and use in order to maintain its excellent ion-diffusion properties. In summary, V₂CBi₂ shows significant application promise as an anode material for both Li- and Na-ion batteries and provides an important theoretical foundation for designing advanced cation battery systems.

The regulation of interfacial phenomena represents an enduring Frontier in modern condensed matter physics and chemical engineering. Systematic thermodynamic and kinetic evaluations, utilizing dynamic light scattering and equilibrium surface measurements, elucidate the regulatory mechanisms of counterion species (Cl⁻vs. CH₃SO₄⁻) and polyoxyethylene (EO) chain lengths on dodecyl fatty amine polyoxyethylene ether quaternary ammonium salts. Methosulfate (CH₃SO₄⁻) series consistently exhibit superior wetting and foaming efficiencies compared to chloride-based systems. This enhanced performance arises from a lower charge density that effectively screens the Stern layer and diminishes the adsorption energy barrier. A non-monotonic structural dependence on EO chain length characterizes the system; extended chains (EO = 15) impart robust steric stabilization yet induce a macroscopic “wetting inertia” due to elevated entropic barriers at the triple-phase contact line. Furthermore, a pronounced reversal in antistatic efficacy is observed: dimethyl sulfate-based systems deliver superior performance for short-chain structures (EO = 2), whereas chloride-based systems dominate at higher ethoxylation degrees (EO = 15). Thermal analysis indicates that bulky CH₃SO₄⁻ ions enhance molecular stability via charge delocalization, whereas Cl⁻ ions induce early thermal degradation by promoting Hofmann elimination. Finally, emulsification stability in polar oils is governed by dipole–dipole interactions, in contrast to the steric hindrance mechanisms prevalent in non-polar systems. These findings establish definitive, molecular-level design rules for optimizing cationic surfactants in advanced industrial formulations.

In order to enhance the recognition properties of a given substrate, to increase the stability of an intermediate or to sequester a pollutant from its medium, the development of suitable confined spaces is an attractive strategy. However, most of the covalent cages described in the literature are based on electron rich scaffolds, thus limiting access to electron deficient confined spaces. Naphthalene diimides are broadly used as π-acidic surfaces and can additionally serve as recognition units through anion–π interactions thanks to their high quadrupole moments. In order to preorganize the naphthalene diimide units into a well-defined confined space, cryptophanes are well-suited because of the rigidity of the cyclotriveratrylene moieties, their bowl shape and their well-known synthesis. Herein, we describe the synthesis of two diastereoisomers of a cryptophane having three naphthalene diimide spacers, their characterization, the resolution of the racemate and their recognition properties towards selected anions and pyrene.

Herein, we report the synthesis of three new binuclear Organoselenium compounds, dicyclopentyl-1H-imidazole-hexyl-2-selenone (MC₁), dibenzyl-1H-imidazole-hexyl-2-selenone (MC₂), and dipentyl-1H-imidazole-hexyl-2-selenone (MC₃), by deprotonation of corresponding imidazolium salts (ML₁–ML₃) via a green synthetic approach. The structure of the newly prepared compounds was characterized through CHN elemental analysis, FTIR, ¹H-NMR, and ¹³C-NMR spectroscopy. Additionally, the in vitro anticancer activity of all the imidazolium salts and selenium adducts was evaluated against A549, MCF-7 cancer cell lines, and EA.hy 926 normal cells by using MTT assays, with 5-fluorouracil as a reference drug. Our findings revealed that all selenium compounds showed a significantly greater anticancer potential than the respective N-heterocyclic carbene salts. Among them, compound MC₂ bearing a benzyl N-substituent was found to be the most effective, with low IC₅₀ = 1.65 ± 0.21 and 2.42 ± 0.61 µM against A549 and MCF-7 cancerous cells, respectively. Furthermore, computational investigation was conducted to theoretically assess the biological potential of newly prepared selenium N-heterocyclic carbene adducts, aiming to discover new anticancer agents.

The present research study investigates photo-galvanic cells by leveraging the halochromic effect of the water-soluble chromotrope 2B dye. Exploitation of the pH-induced structural transitions of this photo-sensitizer in a photo-galvanic system containing a sodium thiosulphate pentahydrate reductant and a sulfamic acid surfactant achieves encouraging solar energy conversion. Experimental results reveal a robust electrical output, including a power of 1195.04 µW, current of 8.27 mA, and potential of 738 mV. The system demonstrated a remarkable conversion efficiency of 3.55% and fill factor of 0.19. Statistical analysis further validated the stability of the system, noting a negative alloy electrode potential (i.e., −830.51 mV). By correlating the halochromic color-shifting properties of chromotrope 2B with cell performance, this study provides critical insights into how pH-sensitive molecular transitions can be strategically exploited for more efficient and sustainable solar energy storage and generation in the future.