The Royal Society of Chemistry最新文献

The electronic transport properties of molecular junctions based on four boron clusters, B₃₂, B₃₉, B₄₂, and B₄₅, that have tubular ground state structures were studied using first principles calculations and non-equilibrium Green's function simulations. Spin polarized calculations indicate that the charge transport properties are almost spin-independent at low bias voltages. In fact, only the junction based on B₃₉ exhibits the spin polarization effect, while the other open-shell cluster (B₄₅) shows no spin dependence due to its coupling with the electrodes. The calculated current-voltage characteristics show that the four types of molecular junctions have diverse functionalities, with the B₃₂ and B₃₉ junctions exhibiting current limiting features, while a clear negative differential resistance effect was found in the B₄₂ and B₄₅ junctions. These results suggest that molecular junctions based on boron clusters, which support rich geometrical and electronic properties, could serve as an important group of candidates for constructing functional molecular devices.

Photodynamic therapy (PDT) has shown good therapeutic results in recent years, but the efficacy is limited by the hypoxic environment within cancer cells. At present, most of the research studies on overcoming PDT hypoxia focus on providing exogenous oxygen, but the effect is not outstanding. This work shows an unconventional source of free radicals, compared with the traditional PDT strategy of generating reactive oxygen species, using a radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), ABVN) to generate alkyl radicals, which is free from the limitation of oxygen, is simpler and more efficient, and has obvious therapeutic effects. By synthesizing hollow mesoporous manganese dioxide (MnO₂) as a carrier, the nanoparticles are loaded with ABVN and encapsulated with PEG, which have excellent photothermal properties, can quickly heat up to the thermal decomposition temperature of ABVN under laser irradiation, can degrade and release ABVN in GSH and acidic environments, and generate a large number of alkyl radicals in a short period of time, with excellent treatment efficiency. This study breaks through the limitation of PDT caused by hypoxia in cancer cells and provides a promising research strategy for PDT treatment.

An electrochemical approach for regioselective 7-endo-dig selenocyclization of N-benzyl propiolamides with diselenides has been developed. This methodology circumvents the need for metal reagents or oxidants, thereby exhibiting excellent functional group tolerance and substrate compatibility. A diverse array of selenated benzo[c]azepinones can be obtained with good to excellent regioselectivity and yields. Furthermore, gram-scale synthesis and subsequent transformations of the products can be readily achieved under straightforward experimental protocols.

Boron nitride (BN) nanomaterials, spanning zero-dimensional (0D) quantum dots, 1D nanotubes, 2D nanosheets, 3D and macroscopic architectures, have garnered emerging attention as functional analogs to carbon-based nanomaterials. Their wide band gap, high thermal conductivity, electrical insulation, and chemical inertness make them versatile candidates for advanced technologies. This review highlights the synthesis-structure-function relationships achieved through top-down methods, such as exfoliation and ball milling, and bottom-up strategies, including chemical vapor deposition and plasma processing. Defect engineering, dopant incorporation, and surface functionalization are further discussed as key levers for tailoring BN nanomaterials' optical, electronic, and interfacial behavior. The review also explores the diverse range of BN nanomaterial applications across various disciplines, such as chemical analysis, biomedicine, catalysis, energy, and aerospace. The recent advances highlight opportunities for data-driven strategies coupled with operando characterization to control and optimize composition, morphology, and defect chemistry. These developments are expected to accelerate translation into practical technologies across wide applications.

1,3-Dipole-based nitrogen containing carbanion, particularly azomethine ylide, is widely used in cycloaddition reactions. It has important and widespread application not only limited in the synthesis of core structural motifs like pyrrolidine and spiropyrrolidines but also in stereocontrolled dipolarophile for building important classes of heterocyclic compounds. Herein, we will explore the current development of azomethine ylide and all the possible applications of this small but elegant fragment using a green approach. This review article will also covers the application of this super energetic, pharmaceutically important moiety in the field of asymmetric, organocatalytic, and transition metal-catalyzed synthesis processes coupled with a theoretical approach. The development of an environmentally safe multicomponent, tandem synthesis method mediated by azomethine ylide will be discussed in detail in this current review article, which will be important for researchers in the field of organic synthesis, heterocyclic chemistry, and medicinal chemistry.

A straightforward and efficient strategy has been established for the synthesis of cinnamic esters and cinnamic acids through the reaction of acrylic anhydride and aryl diazonium salts in a variety of solvents. The reaction to obtain cinnamic esters proceeds smoothly at room temperature in the presence of palladium acetate. In contrast, the formation of cinnamic acids requires basic conditions and is effectively achieved using K₂CO₃ at 80 °C in a DMF/H₂O solvent system. All the desired products were obtained in good yield. The approach offers several notable advantages, including operational simplicity, readily available and inexpensive starting materials, mild reaction conditions, and good product yields. The antioxidant potential of the synthesized cinnamic esters was assessed through radical scavenging activity (RSA) assays, along with their inhibitory effects on amyloid-β (Aβ) aggregation. Most compounds displayed a satisfactory range of RSA, while a subset of the derivatives exhibited moderate Aβ aggregation inhibitory activity.

To meet the increasing demands of the energy storage market, it is imperative to explore and design high-performance anode materials for lithium-ion batteries (LIBs). In this study, we present six types of heterostructures that integrate graphene with BC₂N-II and BC₂N-III sheets to explore the electrochemical properties of BC₂N/graphene systems as potential anode materials for LIBs. Notably, unlike the original BC₂N-II and BC₂N-III sheets, which are incapable of adsorbing Li, our findings demonstrate that Li atoms can indeed be effectively adsorbed onto the BC₂N/graphene heterostructures. Furthermore, the III-HN and III-HH types of heterostructures exhibit significantly enhanced capacity of 414 mAh g⁻¹ along with a minimal energy barrier of 0.13 eV. All the evaluated systems exhibit voltages that completely adhere to the current standards for battery anode material applications. This work offers a theoretical framework for designing viable anode materials featuring heterostructures tailored for LIB applications, offering a practical approach to enhance the performance of pristine materials as anodes. This positions BC₂N-II/graphene and BC₂N-III/graphene as promising candidates for the future developments of lithium-ion battery technology.

The nitrate electroreduction reaction (NO₃^-RR) provides a low-carbon and environmentally friendly strategy for ammonia production. Here, a sustainable method for synthesizing carbon nanosheets is developed by assembling biomass molecules on a boric acid template, followed by thermal annealing. During this process, the introduction of Fe³⁺ and Cu²⁺ ions enables the formation of Fe-doped CuO nanoparticles embedded in carbon nanosheets (Fe-CuO/C). The Fe-CuO/C shows high activity for the NO₃^-RR resulting in a low potential of 0.089 and -0.192 V vs. RHE at -10 and -50 mA cm^-2, with high ammonia yield and faraday efficiency. Theoretical calculations indicate that the *NO to *NOH step is the rate-determining step during the NO₃^-RR. The doping of Fe effectively reduces the energy barrier of this step.

Excited-state intramolecular proton transfer (ESIPT) is a fundamental photochemical process in which photoexcitation induces proton transfer within a molecule, leading to the formation of a tautomeric excited state. It was observed experimentally that the 3-hydroxychromone (3-HC) system exhibits two distinct proton-transfer time scales upon excitation to the lowest bright singlet excited state: an ultrafast component on the femtosecond time scale and a slower one on the picosecond time scale, largely insensitive to solvent effects. Up to now, the microscopic origin of the second time constant has only been hypothesised. Here, using mixed quantum-classical non-adiabatic dynamics simulations, we explicitly observe the two ESIPT time constants and we rationalise the origin of the second time scale by the presence of a competitive out-of-plane hydrogen torsional motion. Comprehensive analysis of the excited-state potential energy surfaces and non-adiabatic trajectories enables us to construct an explicit reaction network for 3-HC, delineating the interplay between direct ESIPT and torsion-mediated pathways. This unified mechanistic framework reconciles the coexistence of ultrafast and slower ESIPT components, offering new insights into the non-adiabatic excited-state dynamics of the system.

Porous anodized aluminium oxide (PAA) has wide and important applications in photonic crystals, energy science, nanotemplates, life science, medicine, aerospace and other scientific research and industrial manufacturing fields. The decisive factors determining its application value and specific performance are its own structural parameters. Therefore, the accurate calculation (but not destructive measurement) of each PAA structural parameter is of great significance for the design and application of PAA structures to satisfy different practical requirements. However, there is a significant problem because multiple distinct formulas proposed by different researchers are used for calculating single independent PAA structural parameters such as the pore diameter. Furthermore, these multiple distinct formulas for determining a single PAA structural parameter frequently yield different results. Compounding this issue, these single structural parameters serve as independent variables in formulas for calculating other PAA parameters. This propagation of uncertainty leads to multiple distinct results for other subsequent parameters. Consequently, in practice, for the calculation of a PAA structural parameter, it is difficult to discern which calculations are the most accurate. Regarding the aforementioned issues, this paper systematically reviews the key structural parameters of PAA and the most commonly used distinct calculation formulas of each key structural parameter. The independent variables of almost all mentioned calculation formulas are unified to the anodization voltage. Subsequently, extensive experimental data published by other researchers are substituted into all the formulas with the unified independent variable to perform an objective competitive screening for the optimal calculation formula of each PAA structural parameter. Finally, on the basis of the competitive screening and independent variable unification, an equation set of PAA structural parameter calculations is proposed for the accurate and convenient calculation of all key PAA structural parameters. The proposal of an equation set for the PAA structural parameter calculation provides a systematic, comprehensive theoretical model and mathematical tool for the design and calculation of PAA structures according to practical requirements in scientific research and engineering applications.