Search

Application of silicon‐based anodes is significantly challenged by low initial Coulombic efficiency (ICE) and poor cyclability. Traditional pre‐lithiation reagents often pose safety concerns due to their unstable chemical nature. Achieving a balance between water‐stability and high ICE in prelithiated silicon is a critical issue. Here, we present a lithium‐enriched silicon/graphite material with an ultra‐high ICE of ≥110 % through a high‐stable lithium pre‐storage methodology. Lithium pre‐storage prepared a nano‐drilled graphite material with surficial lithium functional groups, which can form chemical bonds with adjacent silicon during high‐temperature sintering. This results in an unexpected O−Li−Si interaction, leading to in situ pre‐lithiation of silicon nanoparticles and providing high stability in air and water. Additionally, the lithium‐enriched silicon/graphite materials impart a combination of high ICE, high specific capacity (620 mAh g−1), and long cycling stability (>400 cycles). This study opens up a promising avenue for highly air‐ and water‐stable silicon anode prelithiation methods. [ABSTRACT FROM AUTHOR]

Achieving circularly polarized organic ultralong room‐temperature phosphorescence (CP‐OURTP) with a high luminescent dissymmetry factor (glum) is crucial for diverse optoelectronic applications. In particular, dynamically controlling the dissymmetry factor of CP‐OURTP can profoundly advance these applications, but it is still unprecedented. This study introduces an effective strategy to achieve photoirradiation‐driven chirality regulation in a bilayered structure film, which consists of a layer of soft helical superstructure incorporated with a light‐driven molecular motor and a layer of room‐temperature phosphorescent (RTP) polymer. The prepared bilayered film exhibits CP‐OURTP with an emission lifetime of 805 ms and a glum value up to 1.38. Remarkably, the glum value of the resulting CP‐OURTP film can be reversibly controlled between 0.6 and 1.38 over 20 cycles by light irradiation, representing the first example of dynamically controlling the glum in CP‐OURTP. [ABSTRACT FROM AUTHOR]

Isolation and analysis of tumor‐derived extracellular vesicles (T‐EVs) are important for clinical cancer management. Here, we develop a fluid multivalent magnetic interface (FluidmagFace) in a microfluidic chip for high‐performance isolation, release, and protein profiling of T‐EVs. The FluidmagFace increases affinity by 105‐fold with fluidity‐enhanced multivalent binding to improve isolation efficiency by 13.9 % compared with a non‐fluid interface. Its anti‐adsorption property and microfluidic hydrodynamic shear minimize contamination, increasing detection sensitivity by two orders of magnitude. Moreover, its reversibility and expandability allow high‐throughput recovery of T‐EVs for mass spectrometric protein analysis. With the chip, T‐EVs were detected in all tested cancer samples with identification of differentially expressed proteins compared with healthy controls. The FluidmagFace opens a new avenue to isolation and release of targets for cancer diagnosis and biomarker discovery. [ABSTRACT FROM AUTHOR]

Reaction of isonitriles with 3-(arylamino)isobenzofuran-1(3 H)-ones in the presence of a catalytic amount of an octahydro ( R)-binol-derived chiral phosphoric acid afforded 3-oxo-2-arylisoindoline-1-carboxamides in high yields with good to high enantioselectivities. An enantioselective Ugi four-center three-component reaction of 2-formylbenzoic acids, anilines, and isonitriles was subsequently developed for the synthesis of the same heterocycle. Mechanistic studies indicate that the enantioselectivity results from the dynamic kinetic resolution of the primary Ugi adduct, rather than from the C−C bond-forming process. The resulting heterocycle products are of significant medicinal importance. [ABSTRACT FROM AUTHOR]

Anion-π interactions have been widely studied as new noncovalent driving forces in supramolecular chemistry. However, self-assembly induced by anion-π interactions is still largely unexplored. Herein we report the formation of supramolecular amphiphiles through anion-π interactions, and the subsequent formation of self-assembled vesicles in water. With the π receptor 1 as the host and anionic amphiphiles, such as sodium dodecylsulfate (SDS), sodium laurate (SLA), and sodium methyl dodecylphosphonate (SDP), as guests, the sequential formation of host-guest supramolecular amphiphiles and self-assembled vesicles was demonstrated by SEM, TEM, DLS, and XRD techniques. The intrinsic anion-π interactions between 1 and the anionic amphiphiles were confirmed by crystal diffraction, HRMS analysis, and DFT calculations. Furthermore, the controlled disassembly of the vesicles was promoted by competing anions, such as NO3−, Cl−, and Br−, or by changing the pH value of the medium. [ABSTRACT FROM AUTHOR]

α‐Haloboronates are useful organic synthons that can be converted to a diverse array of α‐substituted alkyl borons. Methods to α‐haloboronates are limiting and often suffer from harsh reaction conditions. Reported herein is a photochemical radical C‐H halogenation of benzyl N‐methyliminodiacetyl (MIDA) boronates. Fluorination, chlorination, and bromination reactions were effective by using this protocol. Upon reaction with different nucleophiles, the C−Br bond in the brominated product could be readily transformed to a series of C−C, C−O, C−N, C−S, C−P, and C−I bonds, some of which are difficult to forge with α‐halo sp2‐B boronate esters. An activation effect of B(MIDA) moiety was found. [ABSTRACT FROM AUTHOR]

Herein we present a new viologen‐based radical‐containing metal–organic framework (RMOF) Gd‐IHEP‐7, which upon heating in air undergoes a single‐crystal‐to‐single‐crystal transformation to generate Gd‐IHEP‐8. Both RMOFs exhibit excellent air and water stability as a result of favorable radical‐radical interactions, and their long‐lifetime radicals result in wide spectral absorption in the range 200–2500 nm. Gd‐IHEP‐7 and Gd‐IHEP‐8 show excellent activity toward solar‐driven nitrogen fixation, with ammonia production rates of 128 and 220 μmol h−1 g−1, respectively. Experiments and theoretical calculations indicate that both RMOFs have similar nitrogen fixation pathways. The enhanced catalytic efficiency of Gd‐IHEP‐8 versus Gd‐IHEP‐7 is attributed to intermediates stabilized by enhanced hydrogen bonding. [ABSTRACT FROM AUTHOR]

Elastic metal–organic materials (MOMs) capable of multiple stimuli‐responsiveness based on dual‐stress and thermally responsive triple‐helix coordination polymers are presented. The strong metal‐coordination linkage and the flexibility of organic linkers in these MOMs, rather than the 4 Å stacking interactions observed in organic crystals, causes the helical chain to act like a molecular spring and thus accounts for their macroscopic elasticity. The thermosalient effect of elastic MOMs is reported for the first time. Crystal structure analyses at different temperatures reveal that this thermoresponsiveness is achieved by adaptive regulation of the triple‐helix chains by fine‐tuning the opening angle of flexible V‐shaped organic linkers and rotation of its lateral conjugated groups to resist possible expansion, thus demonstrating the vital role of adaptive reorganization of triple‐helix metal–organic chains as a molecular spring‐like motif in crystal jumping. [ABSTRACT FROM AUTHOR]

Herein we present a new viologen‐based radical‐containing metal–organic framework (RMOF) Gd‐IHEP‐7, which upon heating in air undergoes a single‐crystal‐to‐single‐crystal transformation to generate Gd‐IHEP‐8. Both RMOFs exhibit excellent air and water stability as a result of favorable radical‐radical interactions, and their long‐lifetime radicals result in wide spectral absorption in the range 200–2500 nm. Gd‐IHEP‐7 and Gd‐IHEP‐8 show excellent activity toward solar‐driven nitrogen fixation, with ammonia production rates of 128 and 220 μmol h−1 g−1, respectively. Experiments and theoretical calculations indicate that both RMOFs have similar nitrogen fixation pathways. The enhanced catalytic efficiency of Gd‐IHEP‐8 versus Gd‐IHEP‐7 is attributed to intermediates stabilized by enhanced hydrogen bonding. [ABSTRACT FROM AUTHOR]

Abstract: Because of the absence of methods for tracking RNA G‐quadruplex dynamics, especially the folding and unfolding of this attractive structure in live cells, understanding of the biological roles of RNA G‐quadruplexes is so far limited. Herein, we report a new red‐emitting fluorescent probe, QUMA‐1, for the selective, continuous, and real‐time visualization of RNA G‐quadruplexes in live cells. The applications of QUMA‐1 in several previously intractable applications, including live‐cell imaging of the dynamic folding, unfolding, and movement of RNA G‐quadruplexes and the visualization of the unwinding of RNA G‐quadruplexes by RNA helicase have been demonstrated. Notably, our real‐time results revealed the complexity of the dynamics of RNA G‐quadruplexes in live cells. We anticipate that the further application of QUMA‐1 in combination with appropriate biological and imaging methods to explore the dynamics of RNA G‐quadruplexes will uncover more information about the biological roles of RNA G‐quadruplexes. [ABSTRACT FROM AUTHOR]