New Journal of Chemistry最新文献

Designing benign catalytic systems is essential to accelerate polymerization research. This requires a thorough understanding of structural interactions between catalysts and monomers. We here report a combined approach involving bench experiments, density functional theory (DFT), and multivariate linear regression (MLR) to elucidate the structure–activity relationships of catalysts. Fluorophenol derived dual organocatalysts were designed and applied for ring-opening polymerization (ROP) of L-lactide (LLA), where the catalytic system exhibits high catalytic activity in bulk at 140 °C. Mechanistic studies revealed a synergistic catalytic process, where the dual organocatalysts activate the initiator and monomer through hydrogen bonding interaction. By applying a multivariate linear regression (MLR) model, the study identifies key electronic and thermodynamic descriptors that significantly influence the observed rate constants (k_obs) in the catalytic process.

Three hexaphenylmelamine phosphors substituted with fluorine at meta, ortho, and para positions were synthesized and characterized, showing increasing phosphorescence lifetimes and quantum yields. Crystal analysis and theoretical calculations suggest that the superior RTP of HPM-p-F is attributed to its higher oscillator strength, increased molecular binding energy, and favorable spin–orbit coupling.

Hydrogen is considered a promising alternative to conventional fossil fuels, as it can be easily produced from renewable energy sources. While electrocatalytic water splitting can achieve near-unity faradaic efficiency in producing hydrogen from water, the widespread implementation of large-scale water electrolysis is hindered by reliance on costly platinum group metal-based electrocatalysts. Here, we report on the rational design of Molybdenum-containing SiCN composites (Mo–SiCN) through an active-filler controlled pyrolysis (AFCOP) strategy. Our investigation into the composite's microstructural evolution revealed the formation of a Mo_4.8Si₃C_0.6 Nowotny phase at a relatively low temperature of 1000 °C. After optimization, the resulting catalyst demonstrated a Tafel slope below 95 mV dec⁻¹ and an overpotential near 575 mV at a normalized current density of 1 mA μF⁻¹. As a proof of concept, the AFCOP strategy was employed to engineer a crack-free Mo–SiCN micropattern, enabling the miniaturization of a Pt-free electrochemical water splitting (EWS) reactor. Produced via soft lithography, the Mo–SiCN pattern exhibits feature sizes ranging from 10 to 200 μm, with near-net-shape replication and a Young's modulus of ≈60 GPa.

Herein, we report an efficient strategy for the synthesis of C4-functionalized novel Pfitzinger acid derivatives via C(sp³)–H bond functionalization. This approach capitalizes on the use of a deep eutectic solvent (DES) comprising N,N′-dimethyl urea and L-(+)-tartaric acid (3 : 1 ratio) at 80 °C as the reaction medium. The 1,2,3,4-tetrahydroacridine-based Pfitzinger acid and its derivatives (methyl/benzyl esters, amides, and Weinreb amides) were used for C4 functionalization with aromatic aldehydes. All the synthesized compounds were evaluated for their dual cholinesterase and α-glucosidase inhibitory activity. Most of the evaluated products showed significant inhibitory activity against AChE, BChE and α-glucosidase enzymes in comparison with standard drug tacrine (AChE IC₅₀ = 201.05 nM; BChE IC₅₀ = 202.14 nM) and acarbose (IC₅₀ = 23 124 nM). Among the tested compounds, 6f showed inhibitory activity with IC₅₀ = 119.45 nM (for AChE) and IC₅₀ = 121.58 nM (for BChE), 6v showed inhibitory activity with IC₅₀ = 121.87 nM (for AChE) and IC₅₀ = 118.25 nM (for BChE) and 9g inhibitory activity against α-glucosidase with IC₅₀ = 21 442 nM. The docking and kinetic studies supported the experimental results obtained through in vitro experiments and predicted drug-like properties.

The pathogenesis of Alzheimer's disease is very complex, so its multifunctional treatment is of great significance, in which the synergistic therapy of the amyloid cascade hypothesis and oxidative stress hypothesis shows good results. In this study, bifunctional carbon dots (CACDs) that can inhibit amyloid aggregation and relieve oxidative stress were synthesized. Studies have shown that CACDs have a good antioxidant effect. When the concentration of CACDs is 100 μg mL⁻¹, the elimination efficiency of DPPH (2,2-diphenyl-1-picrylhydrazyl) reaches 65.57%, and the scavenging efficiency of ˙O₂⁻ and ˙OH reaches 79.6% and 73.9%, respectively. Moreover, CACDs possess outstanding scavenging abilities against the ROS in cells, thus resulting in the mitigation of cellular oxidative damage. Meanwhile, CACDs can also bind to lysozyme proteins through hydrophobic interactions to further interfere with the amyloid self-assembly process. According to thioflavin T (ThT) analysis, the inhibition efficiency of CACDs on amyloid proteins gradually increases with increasing concentration. Circular dichroism spectroscopy (CD) further indicates that the CACDs can inhibit the transition of the protein structure to the β-sheet structure. CACDs and Aβ₄₂ also have strong binding ability. CACDs have excellent biocompatibility and can alleviate the cytotoxicity caused by Aβ oligomers. The results demonstrate that CACDs have promising applications in multifunctional materials and important applications in multi-target therapy of Alzheimer's disease.

Transition metal sulfides (TMS) are promising candidates for sodium-ion battery anodes due to their high theoretical capacities. However, their practical application is limited by high operating voltages (vs. Na⁺/Na) and low initial Coulombic efficiency (ICE). In this study, we present the controlled synthesis of a core–shell structured composite, comprising tin sulfide (SnS) encapsulated within hard carbon microspheres (C@Sn_xS_y@HCS). This composite is prepared using a straightforward chemical bath deposition method followed by low-temperature annealing. The resulting material significantly lowers the average discharge voltage to 0.5 V vs. Na⁺/Na—a reduction of 71.4%—while achieving a relatively high ICE of 73.56%. The composite also exhibits excellent rate performance, delivering 212.5 mA h g⁻¹ at 5 A g⁻¹, and remarkable cycling stability, maintaining 153.3 mA h g⁻¹ after 1000 cycles at the same current density. The core–shell architecture effectively mitigates the volume expansion typically associated with tin sulfides, ensuring a stable solid electrolyte interphase (SEI) and robust electrode interface. This work offers a promising design strategy for developing low-voltage, high-performance sodium-ion battery anodes.

Flavonoid and polyphenol-rich Camellia sinensis (green tea) leaf extract was used to reduce and stabilize forming manganese molybdate (MnMoO₄) nanoparticles, which were prepared by a green synthesis via a hydrothermal method. This approach promotes environmental sustainability by utilizing active components in green tea. The X-ray diffraction (XRD) technique revealed that the MnMoO₄ had a monoclinic crystal structure with a crystallite size of 24.50 nm and d-spacing of 3.51 Å. Nanospheres were observed using scanning electron microscopy (SEM). Also, Brunauer–Emmett–Teller (BET) analysis performed on the material showed that it was a mesoporous material. EIS studies after GCD showed low charge transfer resistance of 0.21 ohm, which showed that the charge transport was good. Cyclic voltammetry (CV) results showed two redox peaks at 0.44 V and 0.31 V signifying pseudo capacitance. Galvanostatic charge–discharge (GCD) tests were performed on MnMoO₄ nanoparticles confirming their high potential for use as supercapacitors with a capacitance of 2115 F g⁻¹ at a current density of 0.8 A g⁻¹. So, MnMoO₄ played a significant role in energy storage applications as they exhibited favorable characteristics that were suitable for the applications.

A mild and efficient continuous-flow catalytic process for the reductive alkylation of methanol by various linear, cyclic, saturated, and unsaturated aliphatic ketones has been developed. This reaction, conducted at 130 °C using a Pd/C cartridge (5 wt%) under 1 bar of hydrogen, yields secondary O-methyl ethers in high yields. This innovative continuous process offers a new route for the synthesis of CPME, as a versatile eco-friendly solvent. Starting from arylic ketones, the same process furnished the corresponding tolyl derivatives via a reductive alkylation/hydrogenolysis sequence. A mechanism is proposed to explain these results.

Electrocatalytic water splitting is a promising, efficient and environmentally friendly method for sustainable hydrogen production, but the development of highly effective electrocatalysts is crucial to enhance its efficiency. In this study, we design and synthesize a novel crystalline polyoxometalate-based metal–organic compound, [H₃(C₅H₅N)₄(PMo₁₂O₄₀)·H₂O], via a simple one-step hydrothermal process. Next, this polymer serves as the molybdenum source for fabricating MoS₂/Ag₂S/NiS@NF electrodes, with AgNO₃ providing silver, thiourea as the sulfur source, and nickel foam (NF) as both the conductive substrate and nickel source. The results reveal stable and homogeneous growth of trimetallic sulfide nanoflakes on the NF surface. The MoS₂/Ag₂S/NiS@NF electrodes exhibit superior electrocatalytic performance compared to many polyoxometalate-based and sulfide-based catalysts, demonstrating a low overpotential of 82 mV and a Tafel slope of 94 mV dec⁻¹ at a current density of 10 mA cm⁻². The enhanced hydrogen evolution reaction activity is primarily attributed to the synergistic interactions and efficient electron transfer across the heterostructured sulfide interfaces, which significantly boost the availability of active sites. The Faraday efficiency of the composite can reach 94%. This work provides a promising approach for the design and fabrication of highly efficient trimetallic sulfide electrocatalysts.

A method for the synthesis of twelve enantiopure derivatives of BEDT-TTF which have two stereogenic centres is reported comprising six diastereomeric pairs. The donors are derivatives of enantiopure (BEDT-TTF)-acetamide bearing a chiral substituent on the nitrogen (NCHMeR: R = 3-Cl-C₆H₄, 3-OMeC₆H₄, 4-Me-C₆H₄, cyclohexyl and 1-naphthyl, and NCH(CH₂Ph)CO₂Me), and structural assignments are supported by X-ray crystallography. All donors show two successive oxidations typical of BEDT-TTF. Two examples of charge transfer salts with members of this series are reported: a 2 : 1 salt with triiodide in which the anions lie in channels along the donor stacking direction and a 1 : 1 salt with TCNQ-F₂ in which the donors and acceptors lie side by side, and staggered with respect to the next layer. Hydrogen bonding between the donors’ amide groups is an important feature in the crystal structures.