Science China Chemistry最新文献

Solid polymer electrolytes (SPEs) have attracted extensive attention by virtue of lightweight and flexible processability for solid-state lithium metal batteries (LMBs) with high energy density and intrinsic safety. However, the SPEs suffer from the trade-off effect between ionic conductivity and mechanical strength. Herein, we report an ionic solid-like conductor with high Li⁺ conductivity and good thermal stability as the conductive phase of polymer electrolytes for advanced LMBs. Using poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) as the polymer matrix, the ionic solid-like conductor can be regarded as a solid plasticizer due to its advantages of non-fluidity and non-leakage. It increases the amorphous region and the dissociation degree of lithium salts in SPEs, while minimizing the loss of mechanical properties. As a result, the Li⁺ conductivity of SPEs incorporating the ionic solid-like conductor is enhanced by four orders of magnitude compared to the blank PVDF-HFP-based electrolyte. The optimized SPE membranes can be processed as thin as 50 µm with a high Young’s modulus of 16.8 MPa, therefore ensuring stable long-term cycling of solid-state LMBs. The Li/Li symmetric cells stably cycled for more than 750 h without short circuits, and the LiFePO₄/Li solid-state batteries demonstrate excellent electrochemical performance over 350 cycles with a capacity retention of 82.5%. This work provides a new strategy for designing ionic solid-like conductors as solid plasticizers for high-performance polymer electrolytes.

The efficient separation of fission products, such as TcO₄⁻ and I⁻, holds strategic significance for the management of radioactive wastes and environmental protection. In this study, we propose an ultrafast strategy for scalable preparation of a highly quaternized organic network to facilitate efficient and synchronous separation of iodide and pertechnetate. The network can be prepared within a few minutes at room temperature, using polyethylenimine and 1,2,4,5-tetrakis(bromomethyl)benzene as building blocks. After chlorine replacement, the network, abundantly decorated with quaternary ammonium groups (Cl@QPN), exhibits an ultrahigh positive charge density of 7.6 mmol/g. This enables the rapid and efficient enrichment of target anions through strong electrostatic Coulomb interactions. As a result, Cl@QPN exhibits significantly higher adsorption rate constants of 0.830 g/(mg min) for ReO₄⁻ (a nonradioactive surrogate of TcO₄⁻) and 0.677 g/(mg min) for I⁻ compared to other materials. Furthermore, it possesses high adsorption capacities, reaching 1,681 mg/g for ReO₄⁻ and 917.4 mg/g for I⁻. Cl@QPN also demonstrates good selectivity towards target ions and shows efficient adsorption for ⁹⁹TcO₄⁻. Additionally, Cl@QPN exhibits high dynamic processing capacities, handling up to 3,100 and 7,400 kg of simulated streams per kilogram of material for I⁻ and ReO₄⁻, respectively.

Reducing CO₂ to carbon-neutral solar fuels can not only alleviate the energy demand but also mitigate the greenhouse effect. At present, developing an efficient non-noble metal photo/electrocatalytic system for converting CO₂ to a specific product beyond CO is still a big challenge. Herein, we report a new cobalt complex bearing 2,2’-bi-1,10-phenanthroline ligand that can photocatalytically reduce CO₂ to formate (HCOO^-). Turnover number (TON) for HCOO^- up to 677 with 99% selectivity can be achieved using organic dyes purpurin as photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole (BIH) as sacrificial reductant in a CO₂-saturated NMP/TEA (v/v, 3:1) solution under visible light irradiation. Controlled potential electrolysis at -1.41 V (vs. Ag/AgCl) in the presence of 12 mM Et₃NHBF₄ also produced HCOO^- with Faradaic efficiency of 39%. Spectroscopic and electrochemical studies suggest that a [Co^I-H] species is the key intermediate for CO₂ reduction.

Reactions involving alkenyl acetates offer cost-effective and environmentally friendly routes for alkene synthesis, yet their asymmetric variant remains elusive. Concurrently, asymmetric conjugate alkenylation predominantly centered on nucleophilic addition using alkenyl—M. This manuscript presents an asymmetric reductive conjugate alkenylation reaction involving alkenyl acetates. The method facilitates the enantioselective addition of keto alkenyl groups to α,β-enones, resulting in the formation of unsaturated diketones—a class of useful structural motifs that are challenging to access otherwise. The use of electron-rich Pyroxy ligand is essential for achieving both high reaction efficiency and enantioselectivity.

Double carbohelicenes have attracted considerable attention due to their aesthetic structures, distinct π-conjugation extension, inherent chirality, and intriguing optical and electronic properties. Herein, the concise de novo synthesis of a new double [5]carbohelicene 1 together with its chiroptical properties, isomerization process and lasing application is presented. 1 was synthesized by a simple protocol involving the formation of a 6,6′-bipentacene as the key intermediate. It is worth noting that 1 existed as two diastereomers 1-PP/MM and 1-PM, which were successfully isolated and unambiguously confirmed by X-ray crystallography. The optical resolution of the racemic 1-PP/MM was successfully achieved by chiral-phase high-performance liquid chromatography (HPLC), and 1-PP and 1-MM were characterized by circular dichroism. Interestingly, it was found that 1-PP/MM could be completely isomerized to 1-PM upon heating, and the detailed thermodynamics and kinetics of the isomerization process were systematically investigated. 1-PM exhibited deep-red luminescence with emission maximum at 723 nm and fluorescence quantum yield as high as 32.95%. Consequently, we can showcase the lasing application of 1-PM by doping with epoxy resin to assemble a bottle microlaser spontaneously, which the lasing wavelength is 796.6 nm at a threshold of 0.8 mJ cm⁻². We believe that our studies, including the facile synthesis methodology, detailed isomerization studies, and lasing application, will shed some light on the design and synthesis of novel carbohelical systems with more functions.

Hepatic ischemia-reperfusion injury (HIRI) is characterized by mitochondrial dysfunction and oxidative stress. Monitoring mitochondrial hydrogen peroxide (mtH₂O₂) levels in real-time through super-resolution imaging is crucial for elucidating its distribution in live cells and its mechanism of action during HIRI. However, low-background fluorogenic probes have been overlooked in the context of super-resolution imaging. In this study, we developed a low-background fluorogenic probe (Mito-WG) with the potential for super-resolution morphology-correlated mitochondrial identification to track the fluctuates of mtH₂O₂ in HIRI. Activation of the desirable fluorescence properties of the probe by mtH₂O₂ was confirmed using structural illumination microscopy (SIM), enabling high-quality mitochondrial imaging with exceptional specificity and sensitivity. Fluctuations in mtH₂O₂ levels were successfully observed in both cellular and rat models of HIRI. Furthermore, we associated the decline in mitochondrial redox homeostasis with accelerated mtH₂O₂ production during HIRI, which triggered mitophagy deficiency and led to cell death. In conclusion, Mito-WG possesses excellent photophysical and low-background properties for SIM imaging, making it a promising tool for mtH₂O₂ tracking in HIRI research and clinical diagnosis.

Herein, we report a novel and highly efficient method for the synthesis of α-phosphoryloxy carbonyl compounds via Ru-catalyzed P(O)O-H insertion reactions of sulfoxonium ylides and phosphinic acids, with the assistance of high-throughput experimentation (HTE) and machine learning (ML). A variety of P(O)O-H derivatives, including diarylphosphates, alkyl phosphates, and alkoxyphosphates, are competent candidates to react with sulfoxonium ylides in this transformation, and various α-phosphoryloxy carbonyls and propylene phosphates are directly constructed. This approach utilizes readily available sulfoxonium ylide as a carbene precursor, and features mild conditions, operational simplicity, and broad functional groups tolerance, and could be used for late-stage functionalization of structurally complex bioactive molecules. Moreover, a conducive exploration of the reaction space is also conducted (756 reactions) and a machine learning model for reaction yield prediction has been developed and applied, showcasing the practical application of this newly workflow (HTE-ML) in the field of synthetic chemistry.

Enhancing the concentration of exogenous molecular drugs within the tumor microenvironment through enzyme-catalyzed polymerization presents a novel strategy for cancer therapy. Nonetheless, the optimization of the catalytic efficiency is often impeded by the inefficient expression of enzymes. Herein, we reported a self-amplifying fluorescent molecular probe, Bis-HTP-ICG, for photodynamic therapy (PDT) and subsequent PDT-induced immunoreaction. The Bis-HTP-ICG probe possesses a noticeable enzyme-catalyzed polymerization facilitated by myeloperoxidase (MPO), a crucial enzyme secreted by neutrophils at inflammation sites. Upon exposure to laser irradiation, Bis-HTP-ICG showed a high PDT efficacy, inducing an acute inflammatory response that stimulates further recruitment of neutrophils and then elevated MPO secretion. The heightened level of MPO enhances the accumulation of the Bis-HTP-ICG via self-polymerization or binding with intratumoral proteins following MPO enzyme catalysis, instigating a self-amplifying chain reaction cycle involving Bis-HTP-ICG, neutrophils and MPO. Meanwhile, PDT efficiently incites immunogenic cell death (ICD) in tumor cells, initiating an anti-tumor immune response including dendritic cells (DCs) maturation, T cell proliferation and reprogramming of tumor-associated neutrophils (TANs). This work portrays a promising strategy for self-amplification of fluorescent molecular probes through adjustable enzyme levels, potentially offering a unique avenue to enhance the tumor accumulation of molecular drugs for improved tumor therapy.

In recent years, the demand for strategic metal resources, essential for scientific and technological progress and industrial development, has multiplied. Ensuring a stable supply of these metals is critical to national security and the well-being of the population. As global industrialization accelerates, the daily demand for nonferrous metals continues to rise. Consequently, extracting and recovering strategic metals from low-grade raw materials, such as solid waste, has become crucial for maintaining their supply and economic development. However, the extraction process is fraught with challenges, including mineral phase stability and complex composition. This review focuses on key strategic metals such as lithium, aluminum, gallium, and vanadium. It introduces and examines various methods for extracting nonferrous metals from different raw materials, including traditional mining technologies applied to low-grade solid wastes. It also outlines future development opportunities and challenges in this field.