No abstract

The development of aqueous zinc metal batteries (AZMBs) is significantly impeded by the poor cycle stability of Zn anodes due to the uncontrolled dendrite growth and low Coulombic efficiency (CE). Herein, for the first time, SeO 2 additives are introduced into ZnSO 4 electrolyte to enhance the stability of the Zn anode. According to the experimental results, the protective ZnSe layer is initially in-situ formed on the Zn surface prior to the Zn plating, which acts as a shield for inhibiting the parasitic reactions and dendrite formation. Moreover, this additive strategy yields the unique characteristic of self-healing for recovering the cracks in the consequence of huge volume change, ensuring the durability of ZnSe layer. Consequently, Zn|Zn symmetric cell using SeO 2 additive delivers an enhanced cumulative plated capacity of 2.1 Ah cm −2 under practical test conditions, which far exceeds the previously reported works. Meanwhile, the average CE of 99.6% for 250 cycles is also demonstrated in Zn|Cu half cells with the presence of the SeO 2 additive. In addition, the positive effect of the SeO 2 additive is further illustrated in the Zn-MnO 2 full cells with a limited Zn.

No abstract

Radical spirocyclization via dearomatization has emerged as an attractive strategy for the rapid synthesis of structurally diverse spiro molecules. We report the use of electrochemistry to perform an oxidative dearomatization...

Corn gluten meal, a corn processing industry by-product, is a good source for the preparation of bioactive peptides due to its special amino acid composition. In the present study, the in vitro and cellular free radical scavenging activities of corn peptide fractions (CPFs) were investigated. Results indicated that CPF1 (molecular weight less than 1 kDa) and CPF2 (molecular weight between 1 and 3 kDa) exhibited good hydroxyl radical, superoxide anion radical and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt (ABTS) radical scavenging activity and oxygen radical absorbance capacity (ORAC). Meanwhile, the in vitro radical scavenging activity of CPF1 was slightly higher than that of CPF2. Both CPF1 and CPF2 also exhibited significant cytoprotective effects and intracellular reactive oxygen species scavenging activity in Caco-2 cells exposed to hydrogen peroxide (H2O2). The amino acid composition analysis revealed that the CPF were rich in hydrophobic amino acids, which comprised of more than 45% of total amino acids. An antioxidant peptide sequence of Tyr-Phe-Cys-Leu-Thr (YFCLT) was identified from CPF1 using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI TOF/TOF MS). The YFCLT exhibited excellent ABTS radical scavenging activity with a 50% effective concentration (EC50) value of 37.63 µM, which was much lower than that of Trolox. In conclusion, corn gluten meal might be a good source to prepare antioxidant peptides.

A Sandmeyer-type transformation of converting aromatic amines into the corresponding arylboronic pinacol esters has been developed.

A Rh(III)-catalyzed C-H activation-desymmetrization of diazabicycles with arenes as an expedient approach to functionalized cyclopentenes is reported. This protocol provides a novel and efficient strategy for the desymmetrization of diazabicycles, featuring simple starting materials, mild reaction conditions, high efficiency and broad substrate scope. Control experiments and a kinetic isotope effect study were conducted, and a plausible mechanism was proposed.

AuCl(3)-catalyzed direct acetoxylation of electron-rich aromatic compounds has been achieved with iodobenzene diacetate as the acetoxylation reagent.