Phase‐Junction Electrocatalysts towards Enhanced Hydrogen Evolution Reaction in Alkaline Media

To ensure sustainable hydrogen production by water electrolysis, robust, earth‐abundant, and high‐efficient electrocatalysts are required. Constructing a hybrid system could lead to further improvement in electrocatalytic activity. Interface engineering in composite catalysts is thus critical to determine the performance, and the phase‐junction interface should improve the catalytic activity. Here, we show that nickel diphosphide phase junction (c‐NiP₂/m‐NiP₂) is an effective electrocatalyst for hydrogen production in alkaline media. The overpotential (at 10 mA cm^?2) for NiP₂‐650 (c/m) in alkaline media could be significantly reduced by 26 % and 96 % compared with c‐NiP₂ and m‐NiP₂, respectively. The enhancement of catalytic activity should be attributed to the strong water dissociation ability and the rearrangement of electrons around the phase junction, which markedly improved the Volmer step and benefited the reduction process of adsorbed protons.     

Increased rigidly triaxial deformations in neutron-rich Mo,Ru isotopes

Pairing-deformation-frequency self-consistent crankingWoods-Saxon model is employed to investigate the triaxiality in the ground states of the neutron-rich even-even Mo, Ru isotopes. Deformation evolutions and transition probabilities have been studied, giving the triaxial shapes in their ground states. The kinematic moments of inertia have been calculated to illustrate the gradually rigid deformation. To understand the origin of the asymmetry shape in this region, we analyze the evolution of single-particle orbits with changing γ deformation. The present calculations reveal the importance of the triaxial deformation in describing not only static property, but also rotational behaviors in this mass region, providing significant probes into the shell structure around.     

Synthesis and Characterization of Ag8(Ge1−x,Snx)(S6−y,Sey) Colloidal Nanocrystals

A facile colloidal approach to synthesize Ag₈(Ge_1?x,Sn_x)(S_6?y,Se_y) nanocrystals (NCs) in a highly controlled way across the entire compositional ranges (0≤x≤1, 0≤y≤6) has been developed. The NCs exhibit a uniform size distribution, highly crystalline structure, over 1 g scalable synthesis, and tunable band gaps in the range of 0.88–1.45 eV by varying their chemical compositions. The Ag₈GeS₆ NCs with a band gap of approximately 1.45 eV were employed as a model light harvester to assess their applicability in solar cells by a full solution‐processing device, yielding an efficiency of 0.28 % under AM1.5 illumination, demonstrating their application potential in solar energy utilization.     

Iodonium Metathesis Reactions

A metathesis reaction occurs when a diaryliodonium triflate is heated with an aryl iodide, resulting in the formation of a new diaryliodonium triflate.     

Cycloaddition reactions of benzyne with olefins

Some novel cycloaddition reactions based on benzyne and olefins have been developed.These reactions were performed in the absence of a transition metal catalyst,and they displayed good yields.These cycloaddition reactions of benzyne with olefins provide effective routes for synthesizing benzocyclobutenes,biaryl compounds and 9,10-dihydrophenanthrene derivatives.     

Light-Induced Chiral Iron Copper Selenide Nanoparticles Prevent β-Amyloidopathy In Vivo

The accumulation and deposition of β-amyloid (Aβ) plaques in the brain is considered a potential pathogenic mechanism underlying Alzheimer's disease (AD). Chiral l/d -Fe_xCu_ySe nanoparticles (NPs) were fabricated that interfer with the self-assembly of Aβ42 monomers and trigger the Aβ42 fibrils in dense structures to become looser monomers under 808 nm near-infrared (NIR) illumination. d -Fe_xCu_ySe NPs have a much higher affinity for Aβ42 fibrils than l -Fe_xCu_ySe NPs and chiral Cu_2−xSe NPs. The chiral Fe_xCu_ySe NPs also generate more reactive oxygen species (ROS) than chiral Cu_2−xSe NPs under NIR-light irradiation. In living MN9D cells, d -NPs attenuate the adhesion of Aβ42 to membranes and neuron loss after NIR treatment within 10 min without the photothermal effect. In-vivo experiments showed that d -Fe_xCu_ySe NPs provide an efficient protection against neuronal damage induced by the deposition of Aβ42 and alleviate symptoms in a mouse model of AD, leading to the recovery of cognitive competence.     

Discovery of a Dual Function Cytochrome P450 that Catalyzes Enyne Formation in Cyclohexanoid Terpenoid Biosynthesis

The 1,3-enyne moiety is commonly found in cyclohexanoid natural products produced by endophytic and plant pathogenic fungi. Asperpentyn ( 1 ) is a 1,3-enyne-containing cyclohexanoid terpenoid isolated from Aspergillus and Pestalotiopsis. The genetic basis and biochemical mechanism of 1,3-enyne biosynthesis in 1 , and other natural products containing this motif, has remained enigmatic despite their potential ecological roles. Identified here is the biosynthetic gene cluster and characterization of two crucial enzymes in the biosynthesis of 1 . A P450 monooxygenase that has a dual function, to first catalyze dehydrogenation of the prenyl chain to generate a cis-diene intermediate and then serve as an acetylenase to yield an alkyne moiety, and thus the 1,3-enyne, was discovered. A UbiA prenyltransferase was also characterized and it is unusual in that it favors transferring a five-carbon prenyl chain, rather than a polyprenyl chain, to a p-hydroxybenzoic acid acceptor.     

Asymmetric Coupling of Carbon-Centered Radicals Adjacent to Nitrogen: Copper-Catalyzed Cyanation and Etherification of Enamides

The first copper-catalyzed asymmetric cyanation and etherification reactions of enamides have been established, where a carbon-centered radical adjacent to a nitrogen atom (CRAN) is enantioselectively trapped by a chiral copper(II) species. Moreover, the asymmetric cyanation of vinyl esters was disclosed as well. These reactions feature very mild reaction conditions and high functional group tolerance, and give a series of chiral α-cyano amides, α-cyano esters and α-hemiaminals in good yields with excellent enantioselectivity. The chiral α-cyano amides can be easily converted into enantioenriched 1,2-diamines and amino acids.     

Effect of ammonia,ammonia-water,and sulfuric acid on the HO2 + HO2 → H2O2 + 3O2 reaction in troposphere: Competition between stepwise and one-step mechanisms

A detailed theoretical study on the reaction mechanisms for the formations of H₂O₂ + ³O₂ from the self-reaction of HO₂ radicals under the effect of NH₃, H₃N···H₂O, and H₂SO₄ catalysts was performed using the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ method. The rate constant was computed using canonical variational transition state theory (CVT) with small curvature tunneling (SCT). Our results indicate that NH₃-, H₃N···H₂O-, and H₂SO₄-catalyzed reactions could proceed through both one-step and stepwise routes. Calculated rate constants show that the catalyzed routes in the presence of the three catalysts all prefer stepwise pathways. Compared to the catalytic efficiency of H₂O, the efficiencies of NH₃, H₃N···H₂O, and H₂SO₄ are much lower due to their smaller relative concentrations. The present results have provided a definitive example of how basic and acidic catalysts influence the atmospheric reaction of HO₂ + HO₂ → H₂O₂ + ³O₂. These results further encourage one to consider the effects of basic and acidic catalysts on the related atmospheric reactions. Thus, the present investigation should have broad implications in the gas-phase reactions of the atmosphere.