New Journal of Chemistry最新文献

It has been four years since the emergence of the COVID-19 pandemic, and the ongoing threat it poses to human health and life underscores the continued need for the development of antiviral medications as a means of mitigating future viral outbreaks. In this study, we present a novel class of antiviral compounds, naphthoquinone-fused enediyne sugar polysulfates, which have demonstrated efficacy against coronaviruses by targeting the conserved receptor binding domain on spike proteins. These compounds induce irreversible damage to the viral proteins that are essential for binding to host cells, resulting in inhibition of viral infection at nanomolar concentrations with minimal cytotoxic effects. Notably, the selectivity index of these compounds exceeds 50 000, suggesting significant potential for further development in antiviral therapeutics against coronavirus.

The aim of this study is to present a straightforward methodology for the preparation of non-precious metal catalysts comprising MnO₂ and carbonaceous materials, namely graphite powder (C), graphitic carbon nitride (gCN), and graphitic carbon nitride/graphite powder (gCN/C) substrates. The morphology and composition of the prepared MnO₂/C, MnO₂–gCN, and MnO₂–gCN/C catalysts have been investigated using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectroscopy (ICP-OES). The electrochemical performance of the prepared MnO₂/C, MnO₂–gCN, and MnO₂–gCN/C catalysts has been investigated for the oxygen reduction reaction (ORR) and oxygen evolution (OER) reaction using cyclic and linear voltammetry. All of the investigated catalysts exhibited enhanced electrocatalytic activity with regard to the ORR and OER processes when compared with the bare substrates. The MnO₂–gCN/C catalyst was found to be the most efficient catalyst for both investigated reactions when compared with MnO₂/C and MnO₂–gCN. The MnO₂–gCN/C catalyst demonstrated the most positive ORR onset potential of 0.9 V and the most negative OER onset potential of 1.53 V. Furthermore, it demonstrated remarkable stability, retaining approximately 85% of its initial signal after a continuous test of 24 hours in both long-term ORR and OER processes.

Herein, (CH₃)₄NMnCl₃ doped with Sb³⁺ single crystals were grown at room temperature. The crystal structure was confirmed by the single-crystal X-ray diffraction at 293 K. The doping of Sb³⁺ not only improves the excitation intensity in the blue-light region but also red emission only from Mn²⁺. The emission intensity (I_e) of (CH₃)₄NMnCl₃:0.5%Sb³⁺ is about 1.5 times higher than that of (CH₃)₄NMnCl₃. The internal and external quantum yield (IQY and EQY) values excited by 450 nm light for the former are 78.6% and 16.0%, which are much higher than those of the latter (56.3% and 10.7%), indicating that Sb³⁺ can effectively transfer energy to Mn²⁺. Moreover, the doping of Sb³⁺ is beneficial to the thermal stability. The I_e of (CH₃)₄NMnCl₃:0.5%Sb³⁺ at 150 °C is about 1.2 times higher than that of (CH₃)₄NMnCl₃ at 25 °C. Meanwhile, the white LED based on (CH₃)₄NMnCl₃:0.5%Sb³⁺ also exhibits good optoelectronic performance. Hence, this work provides a new strategy to explore hybrid manganese(II) chlorides for white LEDs.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for coronavirus disease 2019 (COVID-19), has evoked a global pandemic. Due to its rapid transmission rate and the severity of illness, the urgent need for the expedited design and development of effective therapeutics is evident. Computer-aided drug design (CADD) methods have been employed to accelerate the drug development process. More than 30 000 medication compounds were subjected to virtual screening for the SARS-CoV-2 main protease. The top 10 molecules based on the binding affinity scores were chosen and subjected to extra-precision docking and their pharmacokinetic properties were explored to validate whether they bound well to the SARS-CoV-2 main protease. The results indicated that the binding free energy values between Mpro and these ligands predominantly fall within the range of −7 to −8 kcal mol⁻¹, suggesting relatively stable interactions between the ligands and the protein target. Significant contributions to the binding of most small molecules were identified through molecular dynamics simulations and MM/PBSA (molecular mechanics/Poisson–Boltzmann surface area) analyses, with residues such as His164, Glu166, and Asp187 being found to be crucial. Therefore, these residues have been recognized as potential targets for drug design. In summary, ZINC000306568896 exhibited the optimal binding free energy of −28.68 kcal mol⁻¹ and was evaluated as the lead compound with the strongest binding affinity in this series. Its favourable pharmacokinetic properties and its stable association with the active site suggest that it is a promising lead inhibitor for SARS-CoV-2. These results demonstrate that this ligand has great potential to be an ideal lead inhibitor for SARS-CoV-2 and to expedite the development of therapeutic interventions against COVID-19.

In this paper, four original ternary neodymium complexes, [Nd(hth)₃(L)_x] (where x = 1 or 2; hth = 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)-1,3-hexanedione and L = 1,10-phenanthroline (phen, 1), 5-bromo-1,10-phenanthroline (Brphen, 2), 5-chloro-1,10-phenanthroline (Clphen, 3), and triphenylphosphine oxide (tppo, 4), are reported. The complexes are synthesised by a two-step method and characterized thoroughly. The single crystal X-ray diffraction (SC-XRD) analysis is performed only for complex 4 due to the good quality of its crystals. The SC-XRD analysis indicates that complex 4 possesses an eight-coordinate structure in the solid state, having three hth and two tppo ligands. The ¹H NMR analysis indicates that complexes 1–4 exhibit nine-coordinate structures in solution, having one coordinated water molecule besides hth and ancillary ligands. The Sparkle/PM7 optimized structures of the complexes are also presented, and complex 4 is compared with its crystal structure. Shape analyses reveal that complexes 1, 2, and 3 adopt biaugmented trigonal prism geometry, while complex 4 exhibits biaugmented trigonal prism J50 geometry. The photophysical investigations of the complexes were conducted in both solution and PMMA films in the near infrared (NIR) region. The results show that the hth ligand serves as an effective sensitizer and phen is the best antenna ligand. The TGA/DTA analysis indicates that the complexes are stable up to ∼200 °C, indicating their possible use in optoelectronic devices. Therefore, complex 4 is used as an emitting layer in a NIR-organic light-emitting device (OLED) with the following structure: ITO/MoO₃ (2 nm)/β-NPB (30 nm)/TcTa:[complex 4] (20 nm, 10 wt%)/TPBi:[complex 4] (10 nm, 10 wt%)/TPBi (25 nm)/LiF (0.1 nm)/Al (100 nm).

The development of sustainable polymer materials, such as biodegradable aliphatic polyesters and natural polymers, has recently become an important issue because of the environmental impact of plastic waste. In this study, we demonstrate the novel synthesis of self-assembling peptide-grafted polyesters. The graft copolymers were prepared via radical ring-opening copolymerization of 2-methylene-1,3-dioxolane (C5), a five-membered cyclic ketene acetal, and tetraleucine peptide macromonomers (MA-Leu4-Am) with various feed compositions, and their structures were characterized by ¹H NMR, SEC, and FT-IR analyses. The ring-opening ratio (R_op) of C5 units was almost constant at 70–85% regardless of the feed compositions. In contrast, the values of the grafting ratio of the peptide chain (G_r) were remarkably higher than the values calculated from the feed composition of C5 and MA-Leu4-Am (G_r,feed), reflecting their monomer reactivities. To characterize the copolymerization behavior in detail, density functional theory (DFT) calculations were performed to elucidate the copolymerization mechanisms. These calculations demonstrated that radicals derived from C5 preferentially react with the peptide macromonomer, which was supported by the calculated reaction rate constants and monomer reactivity ratios.

A series of solid-state triplet–triplet annihilation upconversion systems have been developed utilizing a penta-nuclear Yb complex as the sensitizer, converting near-infrared light into blue, green and red photons. The endothermic sensitization of organic annihilators by the Yb complex enables an anti-Stokes shift exceeding 1.3 eV.

The efficient CO₂ conversion to light olefins through hydrogenation is a feasible strategy to achieve carbon neutrality goals. Herein, a series of bimetallic Zn–Zr/supports are synthesized by a conventional impregnation method. We demonstrate that different supports endow catalysts with various specific surface areas, pore sizes, chemical adsorption performances, and acid densities. The effects of different support-loaded Zn–Zr coupled with SAPO-34 on CO₂ hydrogenation to light olefins are investigated systematically. The CO₂ conversion of Zn–Zr/Q10-SAPO-34, Zn–Zr/Q50-SAPO-34, Zn–Zr/γAl₂O₃-SAPO-34, Zn–Zr/MgO-SAPO-34 and Zn–Zr/S-1-SAPO-34 is 11.4%, 9.2%, 24.0%, 8.8%, and 16.2%, respectively, with corresponding light olefin selectivity of 39.0%, 28.1%, 30.4%, 4.8%, and 14.7%, respectively. Significantly, γAl₂O₃ is more conducive to CO₂ conversion, while Q10 tends to produce light olefins. This work provides an effective reference for support selection in CO₂ hydrogenation to light olefins.

High-voltage LiCoO₂ (LCO) cathode materials are in increasing demand in industry, but their stability is greatly affected by serious irreversible phase transitions and interfacial reactions at high voltages. In order to improve these problems faced by LCO cathode materials at high voltages, we improved the stability of LCO at 4.6 V by preparing a PAALi–XG polymer capping layer, which has good toughness as well as electrical conductivity. To be precise, the cladding layer is the product of heat shrinkage polymerization of lithium polyacrylate (PAALi) and xanthan gum (XG), and we found that the cladding layer not only protects the surface of LCO at high voltage, but also improves its ionic and electronic conductivity. According to the electrochemical test results, when the voltage range was 2.75–4.6 V, the modified material possessed a capacity retention of 196.4 mA h g⁻¹ of 82.7% after 200 cycles at a current density of 2C multiplicity for the first turn. It still has a discharge capacity of 183 mA h g⁻¹ at a high current density of 3C. The results indicate that the cladding layer can maintain stability during cycling and prevent side reactions on the surface. The results show that the cladding layer has the ability to isolate the LCO from direct contact with the electrolyte, delay the escape of Co ions, and thus inhibit the generation of irreversible phase transitions, which greatly improves the cycling stability of the LCO.

Pyrazolyl-containing aryliodolium salts undergo transformation to iodopyrazoles accompanied by the formation of a new C^sp2–C^sp2 bond in the presence of a base (DIPEA, NaOH, or K₂CO₃). The plausible mechanism of the base-mediated reaction is suggested. The catalytic activity of the iodine-containing species is studied in the model reaction.