Latest ArticlesA supramolecular assembly composed of perylene diimide derivative (PDI-nm) and nor-seco-cucurbit[10]uril (ns-Q[10]) was designed. The excellent host-guest interaction between PDI-nm and ns-Q[10] prevented the aggregation-caused quenching (ACQ) effect of PDI-nm, resulting in a luminescent assembly. The addition of spermine to the PDI-nm/ns-Q[10] assembly restored the ACQ of PDI-nm due to the competitive binding of spermine to ns-Q[10], which released PDI-nm. The assembly based on this principle showed ultra-high sensitivity for the detection of spermine with a detection limit as low as 7.84 × 10−7 mol/L in aqueous solution and 3.69 × 10−7 mol/L in plasma solution. Moreover, an artificial light-harvesting system based on this assembly was proposed, benefiting from its good luminescent performance. Nile red (NiR) functioned as an acceptor loaded into assembly, and a highly efficient energy transfer process occurred from PDI-nm/ns-Q[10] to NiR, with an efficiency up to 87%.
Piperidine is a crucial pharmacophore and a special scaffold in the realm of drug discovery. Its flexibility increases the molecule's capability to bind to the receptor. The piperidine-containing compounds are distinguished by their remarkable activity, and are increasingly becoming a vital category of pesticides. In this review, the research progress of piperidines in the discovery of pesticides was updated according to their active characteristics. The structure-activity relationships (SARs), and mechanisms of action of piperidine-containing compounds were also discussed. This article is meant to enable readers to quickly understand piperidines, while providing ideas for creating piperidines with novel structures and unique mechanisms of action.
Weakly solvating electrolyte (WSE) demonstrates superior compatibility with lithium (Li) metal batteries (LMBs). However, its application in fast-charging high-voltage LMBs is challenging. Here, we propose a diluent modified WSE for fast-charging high-voltage LMBs, which is formed by adding diluent of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) into the tetrahydropyran (THP) based WSE. A relatively loose solvation structure is formed due to the formation of weak hydrogen bond between TTE and THP, which accelerates the de-solvation kinetics of Li+. Besides, more anions are involved in solvation structure in the presence of TTE, yielding inorganic-rich interphases with improved stability. Li (30 µm)LiNi0.5 Co0.2Mn0.3O2 (4.1 mAh/cm2) batteries with the TTE modified WSE retain over 64% capacity retention after 175 cycles under high rate of 3 C and high-voltage of 4.5 V, much better than that with pure THP based WSE. This work points out that the combination of diluent with weakly solvating solvent is a promising approach to develop high performance electrolytes for fast-charging high-voltage LMBs.
A transition-metal- and oxidant-free amination/cyclization reaction to access 1,2,4-triazolo[1,5-a]pyridines was realized in water by using amino diphenylphosphinate as amino source. A broad array of readily accessible N-(pyridyl)amides could be converted into the products featuring a diverse set of functional groups. The sustainable methodology was successfully applied to the late-stage functionalization of natural products and drugs.
Herein, we report the dynamic kinetic resolution asymmetric acylation of γ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts, and a series of ketals were obtained in high yields (up to 95%) and excellent enantioselectivities (up to 99%). In terms of synthetic utility, the reaction can be performed on a gram scale, and the product can be converted into potential biological nucleoside analog.
Intracellular redox homeostasis is of indispensable importance in pathophysiology. In order to maintain the balance of the redox state within the cell, reactive oxygen species (ROS) and reactive sulfur species (RSS) react and transform with each other, and their levels also directly reflect the degree of oxidative stress and disease. Hypochlorous acid (HClO) and cysteine (Cys) usually co-exist in organisms, interacting with each other in many important physiological processes and synergistically maintaining the dynamic redox balance in the body. To understand the relevance and pathophysiological effects of these two signaling molecules in oxidative stress, unique fluorescence imaging tools are required. Herein, we designed and developed a dual-channel fluorescent probe HP, for the individual and continuous detection of HClO and Cys. This probe could simultaneously monitor the changes in the concentrations of HClO and Cys in cells, and was characterized by a fast response, high sensitivity and high selectivity, especially compared with glutathione (GSH) and homocysteine (Hcy), the probe had a good specificity for Cys. Importantly, probe HP successfully observed dynamic changes in HClO- and Cys-mediated redox status in the oxygen-glucose deprivation/reperfusion (OGD/R) model of HeLa cells and dynamically monitored fluctuations in endogenous HClO levels in lipopolysaccharides (LPS)-induced peritonitis mice.
Hydrogen, as a cheap, clean, and cost-effective secondary energy source, performs an essential role in optimizing today’s energy structure. Magnesium hydride (MgH2) represents an attractive hydrogen carrier for storage and transportation, however, the kinetic behavior and operating temperature remain undesirable. In this work, a dual-phase multi-site alloy (MsA) anchored on carbon substrates was designed, and its superior catalytic effects on the hydrogen storage properties of MgH2 were reported. Mechanism analysis identified that multi-site FeNi3/NiCu nanoalloys synergistically served as intrinsic drivers for the striking de/hydrogenation performance of the MgH2−MsA systems. Concretely, the unique multi-metallic site structure attached to the surface of MgH2 provided substantial reversible channels and accessible active sites conducive to the adsorption, activation, and nucleation of H atoms. In addition, the coupling system formed by FeNi3 and NiCu dual-phase alloys further enhanced the reactivity between Mg/MgH2 and H atoms. Hence, the onset dehydrogenation temperature of MgH2 + 5 wt% MsA was reduced to 195 ℃ and the hydrogen desorption apparent activation energy was reduced to 83.6 kJ/mol. 5.08 wt% H2 could be released at 250 ℃ in 20 min, reaching a high dehydrogenation rate of 0.254 wt% H2/min, yet that for MgH2 at a higher temperature of 335 ℃ was only 0.145 wt% H2/min. Then, the dehydrogenated MgH2−MsA sample could absorb hydrogen from room temperature (30 ℃) and charge 3.93 wt% H2 at 100 ℃ within 20 min under 3.0 MPa H2 pressure. Benefiting from carbon substrates, the 5 wt% MsA doped-MgH2 could still maintain 6.36 wt% hydrogen capacity after 20 cycles. In conclusion, this work provides experimental rationale and new insights for the design of efficient catalysts for magnesium-based solid-state hydrogen storage materials.
Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale, facilitating binding behavior akin to that observed in solution-based processes. DNA nanoprobes hold great promise as miniature detectives capable of detecting miRNAs within cells. However, current nanoprobes face a challenge in achieving the required precision for accurate miRNA detection, particularly within the intricate confines of the cellular microenvironment, due to interference with biological autofluorescence, off-target effects, and a lack of spatiotemporal control. Here, we have designed a dual-stimuli responsive DNA tracker, synergistically utilizing specific intracellular cues and external triggers, which enables spatiotemporal-controlled and precise detection and imaging of miRNAs "on demand". The tracker, which combines zeolitic imidazolate framework-67 (ZIF-67) and unique hairpin DNA structures, effectively anchored onto the ZIF-67 through electrostatic interactions, remains in a dormant state until activated by abundant cellular ATP, resulting in the release of the hairpin structures that include a PC linker incorporated into the loop region. Subsequent irradiation triggers specific recognition of the target miRNA. The newly developed HP-PC-BT@ZIF-67 tracker demonstrates precise spatiotemporal miRNA detection and exhibits excellent biocompatibility, enabling specific miRNA recognition "on demand" within cancer cells. This research presents a reliable miRNA imaging platform in the intricate cellular environment, opening up the possibilities for precise biomedical analysis and disease diagnosis.
Carbonyl compounds are abundant in nature and represent a substantial portion of biomass resources. Despite significant recent progress in homo-coupling of carbonyl compounds, achieving their deoxy-functionalization homo-coupling remains a highly intricate challenge. Herein, we report an entirely novel reaction paradigm: the trifluoromethylative homo-coupling of carbonyl compounds via hydrazones, which enables the formation of three C(sp3)–C(sp3) bonds in a single step. This method provides a new pathway for synthesizing trifluoromethylative coupling product which has unique applications in both fields of medical and material sciences. Mechanistic investigations have unveiled that the formation of a trifluoromethyl-substituted benzyl radical plays a pivotal role as a key intermediate in this reaction.
Membrane distillation (MD) has gained extensive attention for treating highly saline wastewater. However, membrane scaling during the MD process has hindered the rapid development of this technology. Current approaches to mitigate scaling in membrane distillation focus primarily on achieving enhanced hydrophobicity and even superhydrophobicity via utilizing fluorinated fibrous membrane or introducing perfluorosilane modification. Considering the environmental hazards posed by fluorinated compounds, it is highly desirable to develop non-fluorinated membranes with enhanced anti-scaling properties for effective membrane distillation. In this study, we present a non-fluorinated liquid-like MD membrane with exceptional anti-scaling performance. This membrane was facilely fabricated by grafting linear polydimethylsiloxane (LPDMS) onto a hydrophilic polyether sulfone (PES) membrane pre-coated with the intermediate layers of polydopamine and silica (denoted as LPDMS-PES). Remarkably, LPDMS-PES manifested a drastically improved scaling resistance in continuous MD tests than its perfluorinated counterpart, i.e., 1H,1H,2H,2H-perfluorooctyltrichlorosilane-modified PES membrane (PFOS-PES), in both heterogeneous nucleation-dominated and crystal deposition-dominated scaling processes, despite the latter having a smaller surface energy. LPDMS-PES demonstrated a reduction of crystal accumulation of approximately 85% for NaCl and 73% for CaSO4 in the heterogeneous nucleation-dominated scaling process compared to PFOS-PES. Additionally, in the crystal deposition-dominated scaling process LPDMS-PES exhibited a reduction of about 70% in scale accumulation. These results explicitly evidenced the great potential of the liquid-like membrane to minimize scaling in membrane distillation by inhibiting both scale nucleation and adhesion onto the membrane. We believe the findings of this study have important implications for the design of high-performance MD membranes, particularly in the quest for environmentally sustainable alternatives to perfluorinated materials.