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Nature employs sulfur switches, i.e. redox‐active disulfides, to kinetically control biological pathways in a highly efficient and reversible way. Inspired by this mechanism we describe here a DNA‐based synthetic nanodevice that acts as a sulfur switch and can be temporally controlled though redox regulation. To do this we rationally designed disulfide DNA strands (modulators) that hybridize to a ligand‐binding DNA nanodevice and act as redox‐active allosteric regulators inducing the nanodevice to release or load its ligand. Upon reduction, the allosteric modulator spontaneously de‐hybridizes from the nanodevice and, as a result, its effect is transient. The system is reversible and has an unprecedented high tolerance to waste products and
The therapeutic performance of DNAzyme‐involved gene silencing is significantly constrained by inefficient conditional activation and insufficient cofactor supply. Herein, a self‐sufficient therapeutic nanosystem was realized through the delicate design of DNAzyme prodrugs and MnO2 into a biocompatible nanocapsule with tumor‐specific recognition/activation features. The indocyanine green (ICG)‐modified DNA prodrugs are designed by splitting the DNAzyme and then reconstituting into the exquisite catalyzed hairpin assembly (CHA) amplification circuit. Based on the photothermal activation of ICG, the nanocapsule was disassembled to expose the MnO2 ingredient which was immediately decomposed into Mn2+ ions to supplement an indispensable DNAzyme.
CO2‐mediated hydrogen storage energy cycle is a promising way to implement the hydrogen economy, but the exploration of efficient catalysts to achieve this process remains challenging. Herein, sub‐nanometer Pd‐Mn clusters were encaged within silicalite‐1 (S‐1) zeolites by a ligand‐protected method under direct hydrothermal conditions. The obtained zeolite‐encaged metallic nanocatalysts exhibited extraordinary catalytic activity and durability in both CO2 hydrogenation into formate and formic acid (FA) dehydrogenation back to CO2 and hydrogen. Thanks to the formation of ultrasmall metal clusters and the synergic effect of bi‐metallic components, the PdMn0.6@S‐1 catalyst afforded a formate generation rate of 2151 molformate molPd‐1 h‐1 at 353.
Herein we show that corannulene‐based strained π‐surfaces can be obtained through the use of mechanochemical Suzuki and Scholl reactions. Besides being solvent‐free, the mechanochemical synthesis is high‐yielding, fast, and scalable. Therefore, gram‐scale preparation can be carried out in a facile and sustainable manner. The synthesized nanographene structure carries positive (bowl‐like) and negative (saddle‐like) Gaussian curvatures and adopts an overall quasi‐monkey saddle‐type of geometry. In terms of properties, the non‐planar surface exhibits a high electron affinity that was measured by cyclic voltammetry, with electrolysis and in situ UV‐vis spectroscopy experiments indicating that the one‐electron reduced state displays a long lifet.
An enantioselective Rh(II)‐catalyzed cyclooligomerization reaction of thiophenes having triazolyl and vinyl substituents at the 2‐ and 4‐positions is studied. Structurally interesting cyclic trimers whose chirality is ascribed only to the orientation of the 2,4‐disubstituted thiophene rings are obtained. A choice of the patterns of 2,4‐disubstitution for the starting thiophene monomer allows production of either of both enantiomers. The observed electronic circular dichroism spectra accord with those simulated by density functional theory calculations.
Biomolecular droplets formed through phase separation have a tendency to fuse. The speed with which fusion occurs is a direct indicator of condensate liquidity, which is key to both cellular functions and diseases. Using a dual‐trap optical tweezers setup, we found the fusion speeds of four types of droplets to differ by two orders of magnitude. The order of fusion speed correlates with the fluorescence of thioflavin T, which in turn reflects the macromolecular packing density inside droplets. Unstructured protein or polymer chains pack loosely and readily rearrange, leading to fast fusion. In contrast, structured protein domains pack more closely and have to break extensive contacts before rearrangement, corresponding to slower fusion. Thi.
Donor/donor carbenes are relatively new in the field of carbene chemistry; applications in C–H and X–H insertion reactions are few in number, but demonstrate exquisite chemo‐ and stereo‐selectivity. Recent reports have shown that C–H, N–H, B–H, O–H, Si–H, Ge–H, Sn–H and P–H insertion reactions are feasible with a variety of transition metal catalysts, both inter‐ and intra‐molecularly. Furthermore, high degrees of diastereo‐ and enantio‐selectivity have been observed in several cases. Methods typically involve the formation of a diazo‐based carbene precursor, but procedures using diazo‐free metal carbenes have been developed with significant success. This Minireview covers the span of all transition metal catalyzed reactions with donor/dono.
The hydrogenation of benzaldehyde to benzyl alcohol on carbon‐supported metals in water, enabled by an external potential, is markedly promoted by polarization of the functional groups. The presence of polar co‐adsorbates such as substituted phenols enhances the hydrogenation rate of the aldehyde via two effects–polarizing the carbonyl group and increasing the probability of forming a transition state for H addition. These two effects enable a hydrogenation route, in which phenol acts as a conduit for proton addition, with a higher rate than the direct proton transfer from hydronium ions. The fast hydrogenation enabled by the presence of phenol and applied potential overcompensates for the decrease in coverage of benzaldehyde caused by comp.
Efficient conversion of solar energy by means of photocatalysis shows huge potential to relieve energy crisis and environmental pollution. However, the unsatisfied conversion efficiency still hinders its practical application. Introduction of external fields can remarkably enhance the photocatalytic performance of semiconductors from the inside out. This review focuses on the recent advances in the diversified external fields, involving the microwave, mechanical stress, temperature gradient, electric field, magnetic field and coupled fields, boosted photocatalytic reactions, including contaminant degradation, water splitting, CO 2 reduction and bacterial inactivation. The relevant reinforcement mechanisms of photoabsorption, transport and s.
Derivatives based on anthryleno[1,2‐b]pyrazine‐2,3‐dicarbonitrile ( DCPA) are used as luminescent materials, to realize near‐infrared (NIR) electroluminescence. By functionalizing DCPA with aromatic amine donors, two emitters named DCPA‐TPA and DCPA‐BBPA are designed and synthesized. Both molecules have large dipole moments due to the strong intramolecular charge transfer interactions between the amine donors and the DCPA acceptor. Thus, compared with doped films, the emission of neat films of DCPA‐TPA and DCPA‐BBPA can fully fall into the NIR region (>700 nm) with increasing surrounding polarity by increasing doping ratio. Moreover, the non‐doped devices based on DCPA‐TPA and DCPA‐BBPA provide NIR emission with peaks at 838 and 916 nm, res.
Fluorescent probes in the second near‐infrared region (NIR‐II, 1000~1700 nm) have resulted in unprecedented imaging performance. Here, we describe a fluorination strategy in semiconducting polymers for development of highly bright NIR‐II probes. Notably, tetrafluorination yielded a fluorescence QY of 3.2% for the polymer dots (Pdots), over 3‐fold enhancement as compared to non‐fluorinated counterparts. The fluorescence enhancement was attributable to nanoscale fluorous effect in the Pdots that maintained the molecular planarity and minimized the structure distortion between the excited state and ground state, thus reducing the nonradiative relaxations. Followed by through‐skull and through‐scalp imaging of the brain vasculature of live mice.
Spin ice is an exotic type of magnetism displayed by bulk rare‐earth pyrochlore oxides. We discovered a spin ice‐like magnetic relaxation of [{Mn(saltmen)} 4 {Mn(CN) 6 }](ClO 4 )·13H 2 O (saltmen 2− = N,N’ ‐(1,1,2,2‐tetramethylethylene)bis(salicylideneiminate)). This magnetic system can be considered as a two‐dimensional network of Mn III salen‐type single‐molecule magnets (SMMs), in which each SMM unit ( S T = 4) has two orthogonally oriented axial anisotropies and is connected ferromagnetically through the [Mn(CN) 6 ] 3− unit ( S = 1). This work illustrates that a two‐dimensional SMM network with competition between the ferromagnetic interaction and local noncollinear magnetic anisotropies on SMMs is a new type of magnetic system exhibiti.
Development of efficient photothermal nanofibers is of vital importance, but remaining a big challenge. Herein, with reverse thinking of aggregation‐induced emission (AIE) principle, we demonstrate an ingenious and universal protocol for amplifying molecular motions to boost photothermal efficiency of nanofibers. Core‐shell nanofibers having the olive oil solution of AIE‐active molecules as the core surrounded by PVDF‐HFP shell were constructed by coaxial electrospinning. The molecularly dissolved state of AIE‐active molecules allows them to freely rotate and/or vibrate in nanofibers upon photoexcitation and thus significantly elevates the proportion of non‐radiative energy dissipation, affording impressive heat‐generating efficiency. Photo.
In nanoparticle self‐assembly, the current lack of strategy to modulate orientational order creates challenges in isolating large‐area plastic crystals. Here, we achieve two orientationally distinct supercrystals using one nanoparticle shape, including plastic crystals and uniform metacrystals. Our approach integrates multi‐faceted Archimedean polyhedra with molecular‐level surface polymeric interactions to tune nanoparticle orientational order during self‐assembly. Experiments and simulations show that coiled surface polymer chains limit interparticle interactions, creating various geometrical configurations among Archimedean polyhedra to form plastic crystals. In contrast, brush‐like polymer chains enable molecular interdigitation between.
Chemical industry has exploited zeolite shape selectivity for more than 50 years, yet our fundamental understanding remains still limited. Herein, the zeolite channel geometry‐reactive intermediates relationships have been studied in detail over anisotropic zeolite ZSM‐5 crystals during the methanol‐to‐hydrocarbons (MTH) process, using advanced magic angle spinning (MAS) solid‐state NMR (ssNMR) spectroscopy. The utilization of anisotropic crystals enabled the preferential formation of reactive intermediates in single oriented zeolite channels, as revealed by molecular dynamics simulations and in‐situ UV‐Vis diffuse‐reflectance spectroscopy. The ssNMR results show that the slightly more rigid sinusoidal zeolite channels favor the olefin cycl.
Analytical methods that allow simultaneous determination of the concentration and enantiomeric composition of small sample amounts and are also compatible with high‐throughput multi‐well plate technology have received increasing attention in recent years.
The use of photo‐energy represents a promising strategy driving endothermic steam (water) reforming and dry (carbon dioxide) reforming of methane (SRM and DRM) to syngas under mild conditions, but it remains a serious challenge of low syngas selectivity.

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