Chemistry - An Asian Journal最新文献

Two-dimensional graphitic carbon nitride (g-C₃N₄) is a promising photocatalyst, though its efficiency is hindered by fast charge recombination and limited visible-light absorption. In this work, we investigated the influence of stress applied along the armchair (X-axis) and zigzag (Y-axis) directions on the electronic structure and optical properties of monolayer g-C₃N₄ using first-principles calculations. The results show that applied stress effectively tunes the C─N bond lengths and significantly modulates the bandgap: compressive stress substantially reduces the bandgap from 2.64 eV (pristine) to 2.04 eV (−9 GPa, Y-axis) and 2.13 eV (−9 GPa, X-axis), while tensile stress leads to a slight widening. Moreover, a technologically critical indirect-to-direct bandgap transition occurs at specific critical strains—under Y-axis tensile stress exceeding +4 GPa or X-axis compressive stress beyond −6 GPa. This transition promotes direct electron excitation. Density of states analysis reveals the underlying mechanism: compressive stress lowers the conduction band minimum by enhancing the hybridization of C/N-2p orbitals, while tensile stress increases the contribution of s-orbitals. Modifications in optical properties under specific stress conditions significantly extend the visible-light absorption range (380–760 nm). This work establishes stress engineering as an effective strategy for optimizing g-C₃N₄ for optoelectronic and photocatalytic applications.

This review explores the development and application of mechanochromic materials on the basis of commodity and industrially relevant polymers. Mechanochromic polymers, which exhibit visible color changes under mechanical stress, offer promising avenues for creating smart, responsive materials with real-world utility. The review begins by detailing the fundamental mechanisms of mechanochromism, focusing on the role of mechanophores—molecular units that change their optical properties when subjected to force—and their interaction with polymer matrices. Two primary strategies are discussed: physical dispersion of chromogenic dyes and covalent incorporation of mechanophores, each offering distinct advantages in terms of sensitivity, reversibility, and scalability. Special attention is given to commodity plastics, which provide cost-effective platforms for mechanoresponsive technologies. The review also highlights the role of computational modeling in understanding mechanophore activation and guiding material design. Emerging applications in damage sensing, soft robotics, and flexible electronics are examined, demonstrating how mechanochromic systems can bridge scientific innovation and practical deployment. Future challenges and opportunities—such as enhancing sensitivity, improving durability, and integrating sustainable materials—are outlined to inform the next generation of smart mechanochromic devices.

The pursuit of efficient and environmentally benign synthetic routes for electron acceptors via is vital to advancing the commercialization of organic solar cells (OSCs). In this study, we leverage a direct C–H arylation strategy to synthesis a novel A-D-π-D-A-type acceptor (D1), which offers significant advantages in step and atom economy, along with a reduced environmental impact compared to conventional cross-coupling methods. When combined with the polymer donor PM6, the optimized PM6:D1 binary devices attained a power conversion efficiency (PCE) of 9.85%. Furthermore, capitalizing on the well-aligned energy levels and complementary absorption with the benchmark blend PM6:Y6, D1 was successfully incorporated as a third component to fabricate ternary OSCs. The resulting PM6:Y6:D1 devices exhibited more balanced charge transport, enhanced exciton dissociation, and improved photovoltaic parameters, yielding a champion PCE of 16.58%. This work highlights the considerable potential of C–H arylation as a green synthesis method for constructing high-performance acceptors and offers key insights for designing efficient multi-component organic photovoltaic systems.

Herein, we report the rational design and optimization of dithiaarsane-based organoarsenicals that target thioredoxin reductase (TrxR), a selenoenzyme essential for maintaining cellular redox balance and often upregulated in various cancers. Guided by structure–activity relationship (SAR) analysis, refinement of the arsenic–sulfur heterocyclic scaffold afforded compound 37, which exhibits potent cytotoxicity against HL-60 leukemia cells. Mechanistic studies revealed that compound 37 efficiently inhibits TrxR activity, increases intracellular reactive oxygen species, and triggers apoptosis. Collectively, these results, together with the chemically versatile dithiaarsane scaffold established herein, provide a solid foundation for the development of next-generation TrxR-targeted therapeutics and redox-responsive functional molecules.

Developing new molecules for treating bacterial infections and cancer disease is an important area of exploration as both types of cells often develop resistance to known drug candidates. Synthesis, structural characterization, and bioactivity of heterocyclic compounds 6-[2-(benzyloxycarbonyl)diazen-1-yl]-1-10-phenanthroline-5-one (BCDPO) along with 6-[2-(ethoxycarbonyl)diazen-1-yl]-1-10-phenanthroline-5-one (ECDPO) and 6-[2-(methoxycarbonyl)diazen-1-yl]-1-10-phenanthroline-5-one (MCDPO), which are 1,10-phenanthroline-5,6-dione (PD) derivatized with benzyl carbazate (BC), ethyl carbazate (EC), and methyl carbazate (MC), respectively, are studied. The BCDPO crystallized in triclinic system P-1 space group, the supramolecular BCDPO arrays stabilized involving noncovalent O···H and N···H hydrogen bond interactions as well as π–π stacking aromatic interactions. Redox properties studied through cyclic voltammetry and spectroelectrochemistry. The benzyl analog showed better anti-tuberculosis (TB) activity than the methyl and ethyl analogs. The BCDPO shows good minimum inhibitory concentration (MIC) against Mycobacterium tuberculosis (Mtb), which is equivalent to clinically used rifampicin but better than the one of the clinically used drug candidates ethambutol. These compounds exhibit promising anticancer activity against the murine-triple-negative breast cancer (4T1), human breast cancer (MCF-7), and human prostate cancer (PC-3) cancer cell lines. Fluorescence confocal imaging and flow cytometry studies are performed to monitor the compound-induced reactive oxygen species (ROS) generation, nuclear fragmentation, and apoptosis in cancer cell death. The carbazate functionalized phenanthroline derivatives developed are showing promising anti-TB and anticancer activities.

The silicate compound, PbZn₄SiTeO₁₀, was investigated for its structural flexibility and the ensuing properties. The compounds were prepared by conventional solid-state synthesis and the phase purity was confirmed by the powder x-ray diffraction (PXRD). Raman spectroscopy studies indicated the expected bands. XPS analysis was useful in arriving at the oxidation states in the substituted compounds. The substitution of transition metal ions (Co²⁺, Cu²⁺, and Ni²⁺) in place of Zn²⁺ ions in tetrahedral coordination results in new colored compounds, which were characterized by optical absorption spectroscopy with the help of ligand-centered/charge-transfer bands together with the spin-allowed d–d transitions. The white compounds were found to exhibit a good near-infrared (NIR) reflectivity (∼80%), which is comparable to the standard TiO₂ compound. The white compounds also exhibit reasonable dielectric constant values with low loss. Substitution of Eu³⁺ ions at the Pb²⁺ sites (pentagonal bi-pyramidal coordination) results in a deep red emission, with the maximum emission intensity at 7% Eu³⁺ ions substitution. The Co compound, PbZn₃CoSiTeO₁₀, exhibits good performance toward oxygen evolution reaction (OER) with values comparable to RuO₂. The present study explored the structurally characterized PbZn₄SiTeO₁₀ compound toward new colored variants, NIR-reflectivity studies, dielectric behavior, red emission, and electrocatalytic water oxidation (OER).

Heteroannular palladium migration on stacked molecules is one of the keys for achieving distal C–H activation by avoiding the template design. However, the possibility of migration is only realized when a relatively stable palladacycle is formed at a distal position with the aid of a transient directing group. Herein, we have revealed that heteroannular palladium migration facilitated by a monodentate transient directing group, along with an additional ligand, can help to fine-tune the desired bite angle for palladium migration. The developed reaction effectively demonstrates 23 examples of distal heteroannular C–H functionalization of ferrocenecarboxaldehydes, a process that has been less extensively studied compared to the homoannular cyclopentadienyl (Cp) ring C–H activation. Furthermore, the control experiments have been performed to understand monodentate transient directing group (TDG)-enabled heteroannular palladium migration, favored by the monodentate TDG and ligand.

Conventional photoresists often rely on organic solvents and photoinitiators, raising environmental and processing concerns in advanced lithography. In this study, we report an eco-friendly, water-processable photoresist based on poly(vinyl alcohol) modified with N-methyl-4-formylstyrylpyridinium methosulfate (PVA-SbQ), which functions as a photoreversible dual-tone photoresist without requiring photoinitiators and organic solvents. PVA-SbQ copolymers with varying compositions were synthesized via the acetalization reaction between the hydroxyl groups of PVA and the aldehyde functionality of SbQ. Structural characterization using nuclear magnetic resonance (NMR) and Fourier-transform infrared (FT-IR) spectroscopy confirmed the successful incorporation of SbQ moieties into the PVA backbone. The photoreversible behavior of the SbQ groups was systematically investigated using UV–vis and FT-IR analyses, revealing efficient [2 + 2] cycloaddition-driven photodimerization under 365 nm UV irradiation, followed by photocleavage of the cyclobutane ring under deep UV (DUV, 220–260 nm) exposure. Quantitative evaluation indicated a photodimerization degree (PDD) of ∼91.3%, while the photocleavage degree (PCD) reached ∼51.3%, enabling partial recovery of the original state. Optimized as a 10 wt% aqueous formulation, PVA-SbQ demonstrated excellent film-forming ability and photopatternability, achieving well-resolved negative-type, positive-type patterns, and complex square-type patterns, by simply modulating UV exposure conditions. This work presents the potential of PVA-SbQ as a sustainable, functional alternative to conventional photoresists.

Lithium-ion batteries (LIBs) are widely used in consumer electronics, electric vehicles, and energy storage systems due to their high energy density, long cycle life, and low environmental impact. However, the performance of LIBs is inadequate at low temperatures (below 0°C), as evidenced by the reduced capacity, low power output, and shorter cycle life. This is principally due to ineffective electrode material interfacial dynamics, an increased electrolyte viscosity, and an associated increase in the electrode/electrolyte interfacial impedance. The capability of anode materials to store and release lithium ions at low temperatures directly affects the battery's overall performance. Therefore, improving the low temperatures performance of LIBs requires a comprehensive understanding of anode materials in low-temperature environments. In this paper, we review the current state-of-the-art in low-temperature anode materials, analyze the factors that affect performance, and discuss possible optimization strategies and future research directions.

To address the urgent demand for efficient photocatalysts to remove volatile organic pollutants such as methyl tert-butyl ether (MTBE) from aqueous environments, a ZnS/g-C₃N₄ nanocomposite was synthesized via a solvothermal method. Integrating ZnS spheres with 2D graphitic carbon nitride (g-C₃N₄) nanosheets at various ratios enhanced charge separation and light absorption, yielding tunable optical band gaps between 3.23 and 2.59 eV. Photocatalytic degradation of ∼400 ppm MTBE was carried out under visible light (50 W LED lamp, λ > 400 nm, 30 cm length, ∼5200 lumens) using a catalyst dosage of 400 ppm and 90 min illumination. Among the prepared samples, the 30% ZnS/g-C₃N₄ nanocomposite achieved nearly 100% MTBE degradation under visible light. The apparent rate constants followed the sequence: g-C₃N₄ (0.0184 min⁻¹) < ZnS (0.0201 min⁻¹) < 40% ZnS/g-C₃N₄ (0.0273 min⁻¹) < 10% ZnS/g-C₃N₄ (0.0348 min⁻¹) < 20% ZnS/g-C₃N₄ (0.0355 min⁻¹) < 50% ZnS/g-C₃N₄ (0.0372 min⁻¹) < 30% ZnS/g-C₃N₄ (0.0443 min⁻¹). This enhancement demonstrates a strong synergistic interaction between ZnS spheres and g-C₃N₄ nanosheets, resulting in superior photocatalytic performance compared to the individual components.