Chinese Journal of Chemistry最新文献

Quantum dot color conversion (QDCC) technology holds significant promise for next-generation virtual reality/augmented reality displays due to its low cost, high efficiency, and high resolution. However, its advancement is impeded by two primary challenges: the need for high blue light absorption and photo conversion efficiency, and the difficulty of achieving high-resolution patterning of the color conversion layer. This study addresses these challenges by developing a novel bis(2-methacryloxyethyl) phosphate (BMEP)- based photoresist incorporating a high concentration (30 wt%) of perovskite quantum dots (PQDs). The marked superiority of BMEP fundamentally arises from its unique dual functionality. The phosphate group in BMEP exhibits strong affinity for undercoordinated Pb²⁺ sites on nascent PQD surfaces, providing exceptional passivation of surface defects and effectively suppressing ion migration. Concurrently, the photopolymerizable methacrylate end groups of BMEP enable the formation of a densely cross-linked network upon UV exposure, which creates a pronounced spatial confinement effect, physically restricting uncontrolled growth and agglomeration of PQDs. By optimizing exposure time, anti-solvent selection, and annealing parameters, monodisperse PQDs were obtained, resulting in a high blue-light absorption of 99.45% in a 6.3 μm thick film and a high photo conversion efficiency exceeding 41%. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses confirmed that BMEP suppresses PQDs growth distortion through spatial confinement. Using in situ photolithography, red, green, and blue pixel arrays were fabricated, exhibiting photoluminescence quantum yield larger than 80% and covering 91.37% of the Rec. 2020 color gamut. This work introduces a novel strategy for designing high-concentration PQDs photoresists, advancing the development of high-resolution, wide-color-gamut QDs displays.

Organosilicon compounds are widely valuable, making the efficient synthesis of alkenyl silanes an important research goal. A novel catalytic system based on a tridentate anionic ligand and cobalt has been developed for the Markovnikov-selective hydrosilylation of terminal aliphatic alkynes, followed by isomerization of the disubstituted alkenyl silane intermediate, providing efficient access to trisubstituted alkenyl silanes. This system is also highly effective for the Markovnikov hydrosilylation of aryl alkynes. The protocol demonstrates broad functional group tolerance and can be performed on a gram scale. The catalyst achieves a turnover number (TON) of up to 1760 in hydrosilylation reaction. Mechanistic studies suggest that the anionic ligand, upon coordination, forms a dual functional catalyst with cobalt, which is key to enabling this transformation. It is proposed that a cobalt-hydride species selectively catalyzes both the hydrosilylation of terminal alkynes and the subsequent isomerization of the disubstituted alkenyl silane. This work provides an efficient and selective synthetic method using an earth-abundant metal catalyst for alkene synthesis via hydrosilylation and isomerization.

Allylic sulfones represent important structural motifs frequently found in bioactive molecules and serve as versatile synthetic intermediates. Consequently, the development of efficient synthetic routes to these valuable scaffolds remains a significant and ongoing pursuit in chemistry. Conventional synthetic methods often rely on noble-metal catalysts or pre-functionalized substrates and are predominantly limited to the formation of allylic aryl sulfones. Recently, multicomponent sulfonylation strategy involving sulfur dioxide insertion has emerged as an attractive alternative. However, existing approaches within this paradigm generally still require pre-functionalized alkene substrates, and general examples of multicomponent sulfonylation reactions that employ readily available alkenes via SO₂ insertion to afford allylic alkyl sulfones remain scarce. Herein, we report an earth-abundant cobalt metallaphotoredox catalyzed three-component allylic C–H sulfonylation reaction that enables direct and complementary access to allylic alkyl sulfones. This method employs readily available alkenes, DABSO as a sulfur dioxide surrogate, and cyclobutanone oxime esters as radical precursors. Mechanistic investigations reveal that the cobaloxime catalyst plays a dual role, combining photoredox and hydrogen atom transfer (HAT) capabilities, which is critical for driving the transformation. This approach operates without noble-metal catalyst and pre-functionalization, and exhibits operational simplicity, broad functional group tolerance, and high chemo- and regioselectivity. The utility of this methodology is demonstrated through scalable synthesis and late-stage functionalization of pharmaceutical derivatives. This protocol thus provides a novel and complementary route for the direct synthesis of allylic alkyl sulfones from unfunctionalized alkenes.

Transition-metal catalyzed reductive carbosilylation of alkenes with carbon and silyl electrophiles has gained considerable attention for synthetic chemists recently, because it avoids air- and moisture-sensitive pre-prepared organometallic reagents used. However, current carbon electrophiles are limited to alkyl or aryl bromides. Therefore, developing new synthetic approaches by choosing more easily available carbon electrophiles is still in high demand. Herein, we describe a nickel-catalyzed protocol that enables alkylsilylation of acrylonitrile with chlorosilanes and alkyl carboxylic acids via NHPI esters for the construction of various alkylsilanes, in which abundant and easy-accessible carboxylic acids were employed as the new alkyl electrophile sources, overcoming current limitations. This represents the first example of utilizing carboxylic acid as the alkyl reagent in reductive silylative alkylation of alkenes, thus providing a valuable complement to existing methodologies for the synthesis of a variety of organosilanes with diverse structures. Our approach also showcases broad substrate scope (including primary, secondary and tertiary carboxylic acids), good functional group compatibility (tolerating halides, heterocycles, Boc-protected amine, ester, ketone, terminal and internal alkenes, and terminal alkyne) and offers the capability for post-modification of complex agrochemical and pharmaceuticals. In addition, gram-scale reaction further demonstrates the applicable potential of the developed method. Overall, this protocol not only expands the boundaries of reductive difunctionalization reactions of alkenes but also enriches the synthetic toolbox for alkylsilane compounds preparation.

Deploying aqueous Zn batteries as next-generation energy storage systems requires simultaneous improvements in calendar and cycle life, which remain hindered by side reactions such as corrosion and dendrite formation. While recent studies have enhanced cycling stability to some degree, they have largely overlooked calendar life and rarely provided quantified insights into corrosion-induced capacity loss. In this work, we introduce the nonionic surfactant fatty alcohol polyoxyethylene ether (AEO) into a Zn(OTf)₂-based electrolyte to improve calendar and cycle life by inhibiting Zn corrosion and optimizing Zn deposition homogeneity. Owing to its amphiphilic molecular structure, AEO forms a zinc-philic and hydrophobic adsorption layer and spontaneously regulates Zn²⁺ solvation/desolvation structure through enhanced interactions with lone pair electrons, mediating corrosion pathways by limiting solvated and interfacial water molecules. Therefore, the AEO electrolyte suppresses corrosion current by 74.9% and Coulombic efficiency loss by 18.48% after 24-hour aging in a Zn||Cu configuration. Furthermore, a Zn-powder-based full cell with a low negative to positive (N/P) ratio of 2.5 achieves a high capacity retention of 83.37% over 100 cycles, including 20 times of 24-hour intermittent aging. This work sheds light on the mechanism of the surfactant-modified electrolyte and offers a scalable approach for practical long-life aqueous Zn batteries.

Advanced fluorescent anti-counterfeiting technologies have garnered widespread attention due to the insufficient security of traditional anti-counterfeiting methods. Addressing the ongoing demand for more secure anti-counterfeiting methods, we pioneered a simple and effective strategy for the on-demand fabrication of CsPbBr₃ nanocrystalline patterns via direct laser writing on CsPbBr₁.₈I₁.₂ perovskite thin films. The resulting films were comprehensively characterized in terms of morphology, structure, elemental composition, and optical properties. Our investigation reveals that mild laser irradiation induces a reaction between iodide ions and ambient oxygen, leading to iodide depletion and local bromide enrichment with replacing the lattice positions of these iodide vacancies. This halide exchange facilitates the formation of CsPbBr₃ nanocrystals, which exhibit bright green luminescence under 365 nm UV excitation. At higher laser intensities, blue luminescence can also be achieved, attributed to the smaller crystal sizes. By leveraging programmable design, we successfully generate green- and dual-emissive patterns within otherwise non-luminescent CsPbBr₁.₈I₁.₂ films, offering a promising route for optical anti-counterfeiting applications. This work demonstrates a novel, laser-assisted technique for the controlled creation of fluorescent security features.

Aminyl radicals of the type •NR₂, featuring a nitrogen-centered unpaired electron, are highly reactive intermediates that are notoriously difficult to isolate in the condensed phase. Herein, we report the synthesis of thio-, seleno- and telluro-aminyl radicals 2–4, obtained in one step from reactions of an isolable triplet nitrene with diphenyldichalcogenides. Radicals 3 and 4 represent the first stable examples of seleno- and telluro-substituted aminyl radicals. Compounds 2–4 were characterized by single-crystal X-ray diffraction, electron paramagnetic resonance and UV/Vis absorption spectroscopy. This work not only expands the family of isolable nitrogen-centered radicals, but also opens new avenues for main-group radical chemistry involving heavier p-block elements.

Three-dimensional covalent organic frameworks (3D COFs) have attracted significant research interest due to their unique structures. However, the interpenetration phenomenon exists in most 3D COFs, which compresses pore space, reduces effective pore volume and specific surface area, and thus limits the performance of these materials in fields such as adsorption and catalysis. Therefore, developing non-interpenetrated 3D COFs is challenging yet of great significance. In this study, a symmetry reduction strategy was employed to construct a jca topological 3D COF (JUC-643) with a unique double-helix structure. Powder X-ray diffraction (PXRD) and topological analysis confirmed it as a non-interpenetrated [4+3(+2)]-c net, overcoming the interpenetration tendency of traditional [8(+2)]-c or [6(+2)]-c net. Benefiting from the non-interpenetrated characteristic, the framework retains sufficient pore space, providing ample accommodation for molecular adsorption. At 298 K and 1 bar, JUC-643 exhibits adsorption capacities of 2.47 mmol·g^–1 for C₃H₈ and 3.32 mmol·g^–1 for n-C₄H₁₀. This study not only offers a generalizable method for the design of non-interpenetrated 3D COFs but also confirms their application potential in light hydrocarbon adsorption.

Water microdroplets provide a unique environment that facilitates chemical reactions at the air-water interface. Here, we provide mass spectrometric evidence that several types of fluorinated ethanol increase their acidity and undergo efficient deprotonation at the air–water interface of microdroplets, generating anions that capture CO₂ to form stable fluoroethoxyformate products. While increased fluorine substitution enhances the acidity by stabilizing conjugate bases through electron-withdrawing effect, it simultaneously reduces the nucleophilicity of the bases by delocalizing their negative charges from oxygen atoms. This correlation between acidity of fluorinated ethanols and nucleophilicity of their conjugate bases results in monofluorinated ethanol exhibiting the highest reactivity toward CO₂. Our results elucidate how fluorine substitution modulates anion reactivity and provide a strategy for CO₂ capture in microdroplets where the acidity of various substances could be greatly increased.

Understanding the interfacial interactions between covalent organic frameworks (COFs) and polymer matrices remains a critical challenge for the development of high-performance mixed matrix membranes (MMMs) for gas separation and mechanical robustness. Here, we systematically study MMMs made of highly crystalline and monodispersed 2D PDA-HTA COF and 3D-Py-COF with commonly used PIM-1 and 6FDA-DAM as matrix. A comprehensive gas permeation, electron microscopy and mechanical properties analysis revealed that the incorporation of these porous fillers universally decreased gas permeability, which is mainly due to polymer chain infiltration. The large pores of the 2D COF promote deep polymer penetration, leading to pore blockage and the formation of a rigidified, selective interfacial region. In contrast, the small pores of the 3D COF largely prevent infiltration, resulting in a more classic, weakly-adhered filler. Crucially, this same infiltration mechanism dictates the composite's mechanical properties, inducing complex plasticization and reinforcement phenomena that are highly dependent on the specific COF-polymer pairing. These findings offer mechanistic insights and design principles for optimizing the interface in MMMs, paving the way for advanced membranes with both excellent separation and mechanical performance.