Superconducting Fiber with Transition Temperature up to 7.43 K in Nb₂Pd_<i>x</i>S_5−δ (0.6 < <i>x</i> <1)

Wiring systems powered by highly efficient superconductors have long been a dream of scientists, but researchers have faced practical challenges such as finding flexible materials. Here we report superconductivity in Nb₂Pd_<i>x</i>S_5−δ fibers with transition temperature up to 7.43 K, which have typical diameters of 0.3–3 μm. Superconductivity occurs in a wide range of Pd (0.6 < <i>x</i> <1) and S (0 < δ <0.61) contents, suggesting that the superconductivity in this system is very robust. Long fibers with suitable size provide a new route to high-power transmission cables and electronic devices

DataSheet1_A novel exfoliated manganese phosphoselenide as a high-performance anode material for lithium ions storage.docx

Layered manganese phosphoselenide (MnPSe3) is expected to be a potential anode for Li ions storage due to it combines the merits of phosphorus with metal selenide. It promotes charge transfer and ensures a high theoretical capacity of up to 746 mA h g−1. In this work, a comprehensive study clearly demonstrated that bulk MnPSe3 electrode is the inability to maintain the integrity of the structure with severe detectable fracture or pulverization after full lithiation/delithiation, resulting in poor rate capability and cycling stability. Additionally, exfoliated few-layered MnPSe3 nanoflakes by the ultrasonic method show enhanced electrical conductivity and resistance to volume expansion. It has a high initial discharge/charge capacity reaching to 524/796 mA h g−1 and outstanding cycling stability with charge capacities of 709 mA h g−1 after 100 cycles at 0.2 A g−1 within the potential window of 0.005–3 V vs. Li+/Li. While further improving the cycles, the retention rate was still held at ∼72% after 350 cycles. This work provides new insights into exploiting new novel layered materials, such as MnPSe3 as anodes for lithium-ion batteries.</p

Aromatic Interlinking of M₄L₄ Lantern Cages into Porous Films by Postsynthetic Electropolymerization

We report the aromatic interlinking of metal–organic cages into porous films on conductive substrates through a postsynthetic electrochemical coupling pathway. A bidentate ligand decorated with an electroactive 9-phenyl-carbazolyl group is synthesized and subsequently coordinated with the paddlewheel clusters of Rh-, Cu-, and Ru-acetates to yield the [4 + 2] lantern cages. Multisweep cyclic voltammetry (CV) is applied to trigger the electropolymerization of these cages via dimerization of the peripheral carbazolyls, which leads to the in situ formation of uniform coatings on diverse current collectors (e.g., ITO glass, Ni foam, Au-decorated Si wafer) on demand. The thickness of the film can be finely tuned in a range of ca. 5–50 nm simply by varying the CV cycles. The resulting polycage products obtained after 10 CV cycles reveal a mesoporous structure with randomly distributed cavities with a diameter of ca. 15–35 nm. The porous films show electrical conductivity with a sheet resistance of as low as ca. 83 Ω on ITO glass and rapid ionic transfer kinetics with a low charge transfer resistance of ca. 40 Ω on Ni foam. These features prominently reduce the overpotentials and accelerate the catalytic kinetics in electrocatalytic water splitting compared to the blenders of the cage monomer and Nafion binder

<i>N</i>,<i>N′</i>-Dioxide/Gadolinium(III)-Catalyzed Asymmetric Conjugate Addition of Nitroalkanes to α,β-Unsaturated Pyrazolamides

A highly efficient <i>N</i>,<i>N</i>′-dioxide/Gd­(III) complex has been developed for the enantioselective conjugate addition of nitroalkanes to α,β-unsaturated pyrazolamides. Under mild reaction conditions, a series of γ-nitropyrazolamides were obtained in good to excellent yields (up to 99%) with excellent enantioselectivities (up to 99% ee). What’s more, the optically active products could be easily transformed into γ-nitroesters which were key intermediates for the preparation of paroxetine, pregabalin and boclofen

Enantioselective Baeyer–Villiger Oxidation: Desymmetrization of Meso Cyclic Ketones and Kinetic Resolution of Racemic 2‑Arylcyclohexanones

Catalytic enantioselective Baeyer–Villiger (BV) oxidations of racemic and meso cyclic ketones were achieved in the presence of chiral <i>N</i>,<i>N</i>′-dioxide–Sc^III complex catalysts. The BV oxidations of prochiral cyclohexanones and cyclobutanones afforded series of optically active ε- and γ-lactones, respectively, in up to 99% yield and 95% ee. Meanwhile, the kinetic resolution of racemic 2-arylcyclohexanones was also realized via an abnormal BV oxidation. Enantioenriched 3-aryloxepan-2-ones, whose formation is counter to the migratory aptitude, were obtained preferentially. Both the lactones and the unreacted ketones were obtained with high ee values

Correction to Enantioselective Baeyer–Villiger Oxidation: Desymmetrization of Meso Cyclic Ketones and Kinetic Resolution of Racemic 2‑Arylcyclohexanones

Correction to Enantioselective Baeyer–Villiger Oxidation: Desymmetrization of Meso Cyclic Ketones and Kinetic Resolution of Racemic 2‑Arylcyclohexanone

Enantioselective Baeyer–Villiger Oxidation: Desymmetrization of Meso Cyclic Ketones and Kinetic Resolution of Racemic 2‑Arylcyclohexanones

Catalytic enantioselective Baeyer–Villiger (BV) oxidations of racemic and meso cyclic ketones were achieved in the presence of chiral <i>N</i>,<i>N</i>′-dioxide–Sc^III complex catalysts. The BV oxidations of prochiral cyclohexanones and cyclobutanones afforded series of optically active ε- and γ-lactones, respectively, in up to 99% yield and 95% ee. Meanwhile, the kinetic resolution of racemic 2-arylcyclohexanones was also realized via an abnormal BV oxidation. Enantioenriched 3-aryloxepan-2-ones, whose formation is counter to the migratory aptitude, were obtained preferentially. Both the lactones and the unreacted ketones were obtained with high ee values

Superconductivity with Topological Surface State in Sr_<i>x</i>Bi₂Se₃

By intercalation of alkaline earth metal Sr in Bi₂Se₃, superconductivity with large shielding volume fraction (∼91.5% at 0.5 K) has been achieved in Sr_0.065Bi₂Se₃. Analysis of the Shubnikov–de Hass oscillations confirms the half-shift expected from a Dirac spectrum, giving transport evidence of the existence of surface states. Importantly, Sr_<i>x</i>Bi₂Se₃superconductor is stable under air, making Sr_<i>x</i>Bi₂Se₃ an ideal material base for investigating topological superconductivity

Regio- and Enantioselective Baeyer–Villiger Oxidation: Kinetic Resolution of Racemic 2‑Substituted Cyclopentanones

A kinetic resolution of racemic 2-substituted cyclopentanones via highly regio- and enantioselective Baeyer–Villiger oxidation has been successfully developed. The reaction could afford the normal 6-substituted δ-lactones in up to 98% ee and >19/1 regioselectivity. Meanwhile, the unreacted ketones were recovered in excellent ee values (up to 98%). It represents the best results of the kinetic resolution of racemic 2-substituted cyclopentanones via nonenzymic asymmetric BV oxidation