Coral reef-like polyanaline nanotubes prepared by a reactive template of manganese oxide for supercapacitor electrode

Coral reef-like PANI nanotubes composed of nanopaticles were successfully synthesized by a reactive template of manganese oxide.The structure was characterized by using SEM,TEM,and FT-IR,and the supercapacitive behaviors of these nanotubes were investigated with cyclic voltammetry（CV）,and charge-discharge tests,respectively.A maximum specific capacitance of 533 F/g could be achieved in 1mol/L aqueous H₂SO₄ with the potential range of -0.2 to 0.8 V（vs.the saturated calomel electrode） in a half-cell setup configuration for PANI electrode,suggesting its potential application in the electrode material for electrochemical capacitors.     

A Facile Oxidation of Thiols to Disulfides Catalyzed by CoSalen

Abstract

A convenient and facile catalytic oxidation of thiols to the corresponding disulfides is described using CoSalen as the catalyst and air as the oxidizing agent. This new approach provides an efficient method for the preparation of symmetrical disulfides in high yields and under mild conditions.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Spectroscopic Identification of Products 3a–3l.]     

Comparative pyrolysis upcycling of polystyrene waste: thermodynamics, kinetics, and product evolution profile

Pyrolysis is one important way to treat polystyrene waste and upcycle it into useful materials. A comparative pyrolysis study of virgin polystyrene (VPS) and two types of commonly used polystyrene products, expanded polystyrene (EPS) and polystyrene container (CPS) was carried out. Various values were found in the thermodynamic study and kinetic study of VPS, EPS, and CPS pyrolysis, suggesting distinct thermal degradation characteristics of these materials. The energy barrier order of the pyrolysis processes was EPS, CPS, VPS, showing activation energy of 230, 219, and 145 kJ mol^?1, respectively. The order of amount of heat absorbed was EPS, CPS, VPS, with enthalpy of 224, 213, and 139 kJ mol^?1, respectively. The reaction favorability order was EPS, CPS, and VPS with Gibbs free energy of 118, 132, and 210 kJ mol^?1, respectively. Thermogravimetric analysis indicated the use of high heating rate would increase the reaction rate and shorten the reaction time. Product evolution profiles showed that VPS and CPS pyrolysis produced mainly aromatics, while EPS pyrolysis produced aromatics at the initial phase of the reaction and aliphatic hydrocarbon at the latter phase. The diverse pyrolysis behaviors of VPS, EPS, and CPS demonstrated that an examination on different polystyrene materials was desired to optimize the pyrolysis conditions and product distribution, and thus benefit the process of valuable materials recovery.     

First Total Synthesis of (±)-Kenusanone B

The first total synthesis of a natural prenylflavanone, (±)-kenusanone B (1) has been achieved by condensation of acetophenone 4 and benzaldehyde 6 followed by cyclization and deprotection. Chloromethyl methyl ether was used as a facile protecting reagent of free hydroxy groups for the synthesis of polyhydroxylated flavanones.     

A one-pot tandem synthesis of various 1,2-disubstituted benzimidazoles

A facile method to synthesize various 1,2-disubstituted benzimidazoles is developed. It is suggested that formation of a Meisenheimer adduct between the substrate, amine, and solvent aids the N-arylation process. The generality of the protocol is demonstrated by the efficient reactions involving numerous substituents ranging from electron-withdrawing groups to electron-donating groups.     

Neutral 1D Perovskite-Type ABX3 Phase Transition Material with a Narrowband Emission and Semiconductor Property

Cyclic organic amines are emerging as excellent building blocks to assemble organic–inorganic hybrid phase transition materials due to their flexible cyclic structure. Here, we have assembled a 1D organic-inorganic hybrid dielectric material C₅H₆NOPbBr₃ ( 1 ) by alloying the cyclic organic amine 3-hydroxypyridine. 1 displays a remarkable switchable dielectric response induced by an order-disorder transformation of the organic moiety, this transformation behaviour is confirmed by DSC and Hirshfeld surface measurements. More interestingly, 1 has a narrowband emission (FWHM=4.64 nm) at 590 nm; FWHM is a major quality figure for narrowband photodetectors. In addition, 1 exhibits semiconducting properties with an indirect bandgap of 2.78 eV by the analysis of the UV-Vis absorption results.     

Improved Stabilities of Labeling Probes for the Selective Modification of Endogenous Proteins in Living Cells and In Vivo

To date, various affinity-based protein labeling probes have been developed and applied in biological research to modify endogenous proteins in cell lysates and on the cell surface. However, the reactive groups on the labeling probes are also the cause of probe instability and nonselective labeling in a more complex environment, e. g., intracellular and in vivo. Here, we show that labeling probes composed of a sterically stabilized difluorophenyl pivalate can achieve efficient and selective labeling of endogenous proteins on the cell surface, inside living cells and in vivo. As compared with the existing protein labeling probes, probes with the difluorophenyl pivalate exhibit several advantages, including long-term stability in stock solutions, resistance to enzymatic hydrolysis and can be customized easily with diverse fluorophores and protein ligands. With this probe design, endogenous hypoxia biomarker in living cells and nude mice were successfully labeled and validated by in vivo, ex vivo, and immunohistochemistry imaging.     

Elucidating the Binding Mode between Heparin and Inflammatory Cytokines by Molecular Modeling

Heparan sulfate (HS) interacts with a broad spectrum of inflammatory cytokines, thereby modulating their biological activities. It is believed that there is a structural-functional correlation between each protein and sugar sequences in the HS polysaccharides, however, the information in this regard is limited. In this study, we compared the binding of four inflammatory cytokines (CCL8, IL-1beta, IL-2 and IL-6) to immobilized heparin by an SPR analysis. To define the molecular base of the binding, we used a heparin pentasaccharide as representative structure to dock into the 3D-molecular structure of the cytokines. The results show a discrepancy in K_D values obtained by SPR analysis and theoretical calculation, pointing to the importance to apply more than one method when describing affinity between proteins and HS. By cluster analysis of the complex formed between the pentasaccharide and cytokines, we have identified several groups in heparin forming strong hydrogen bonds with all four cytokines, which is a significant finding. This molecular and conformational information should be valuable for rational design of HS/heparin-mimetics to interfere cytokine-HS interactions.