Thermogravimetric study of the reduction of basic lead sulphate

In this paper, the results of the study of the reduction of basic lead sulphate with a gas (CO + CO₂) mixture are presented. This is a secondary reaction during the reduction of lead sulphate. The change in the both lead and PbS content in the reaction products, depending on the process temperature and the composition of the gaseous phase, was established. The comparison of the rate of the reduction reaction of lead sulphate and basic lead sulphate shows that the process proceeding with a higher output is the reduction of basic lead sulphate.     

Synthesis of polyaniline/Au composite nanotubes and their high performance in the detection of NADH

Polyaniline (PANI)/Au composite nanotubes were synthesized and developed as an electrode material for a nicotinamide adenine dinucleotide (NADH) sensor. A MnO₂ self-degradable template method was used to prepare the tube-like PANI nanomaterial. By introducing PANI nanotubes into Au colloid, Au nanoparticles (NPs) were successfully decorated onto the surface of PANI nanotubes through electrostatic effects. The morphology, composition, and optical properties of the resulting products were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) absorption spectra, and thermogravimetric analysis (TGA). In addition, the obtained PANI/Au composites were used as catalysts for the electrochemical oxidation of NADH. Cyclic voltammogram (CV) experiments indicated that PANI/Au-modified glassy carbon electrode showed a higher electrocatalytic activity towards the oxidation of NADH in a neutral environment. Differential pulse voltammogram (DPV) results illustrated that the fabricated NADH sensor had excellent anti-interference ability and displayed a wide linear range from 4?×?10^?4 to 8?×?10^?3 M with a detection limit of 0.5?×?10^?7 M.     

A novel electrochemiluminescence glucose biosensor based on platinum nanoflowers/graphene oxide/glucose oxidase modified glassy carbon electrode

A novel electrochemiluminescence (ECL) biosensor based on platinum nanoflowers (PtNFs)/graphene oxide (GO)/glucose oxidase (GODx) was discovered for glucose detection. PtNFs/GO was synthesized using a nontoxic, rapid, one-pot and template-free method and characterized by transmission electron microscopy (TEM) and high-resolution TEM techniques. The as-prepared PtNFs/GO with clean surface and multiporous structure was used to assemble GODx to form a glucose biosensor. Based on ECL results, the PtNFs/GO/GODx film-modified electrode displayed a high electrocatalytic activity towards the oxidation of glucose, which generated hydrogen peroxide (H₂O₂) to react with the luminol radicals thus enhanced the luminol ECL. Under the optimized conditions, two linear regions of ECL intensity to glucose concentration were valid in the range from 5 to 80 μmol/L (r?=?0.9957) and 80 to 1,000 μmol/L (r?=?0.9909) with a detection limit (S/N?=?3) of 2.8 μmol/L. In order to verify the reliability, the thus-fabricated biosensor was applied to determine the glucose concentration in glucose injection, glucose functional drink, and blood serum. The results indicated that the proposed biosensor presented good characteristics in terms of high sensitivity and good reproducibility for glucose determination, promising the applicability of this sensor in practical analysis.     

Rhodium(III)‐Catalyzed ortho Alkenylation of N‐Phenoxyacetamides with N‐Tosylhydrazones or Diazoesters through CH Activation

A coupling reaction of N‐phenoxyacetamides with N‐tosylhydrazones or diazoesters through Rh^III‐catalyzed C? H activation is reported. In this reaction, ortho‐alkenyl phenols were obtained in good yields and with excellent regio‐ and stereoselectivity. Rh–carbene migratory insertion is proposed as the key step in the reaction mechanism.     

Magnolol and honokiol included green emissive terbium sol–gel materials and their recognition behaviors

Magnolol and honokiol as pharmaceutical ligands have been introduced into terbium complex systems for the first time and two hybrid organic–inorganic materials were successfully prepared. Both of them can sensitize terbium characteristic green emission effectively based on intra-molecular energy transfer channel. Moreover, they selectively recognized Cu²⁺ and Fe³⁺ through luminescence quenching effects. The photophysical properties and morphological structures were extensively investigated.     

Platinum Complexes Containing Pyramidalized Germanium and Tin Dihalide Ligands Bound through σ,σ ME Multiple Bonds

We present the isolation of the first mononuclear dihalogermylene, and mono‐ and dinuclear stannylene complexes of transition metals. These exhibit exceptionally pyramidalized Group 14 centers. Additionally, removal of the halide substituents from the Ge/Sn atom was successfully performed in two ways, halide abstraction and reduction, leading to a variety of unusual structural motifs.     

Highly Enantioselective Ring‐Opening Reactions of Aziridines with Indole and Its Application in the Building of C3‐Halogenated Pyrroloindolines

A magnesium‐catalyzed asymmetric ring‐opening reaction of aziridine with indole has been realized by employing commercially available chiral ligands. Both of the enantiomers of the ring‐opening product could be obtained with good yields and a high level of enantioselectivity. The corresponding ring‐opening product could be further transformed to various types of enantioenriched C₃‐halogenated‐pyrroloindolines.     

Facile Access to cis‐2,6‐Disubstituted Tetrahydropyrans by Palladium‐Catalyzed Decarboxylative Allylation: Total Syntheses of (±)‐Centrolobine and (+)‐Decytospolides A and B

cis‐2,6‐Tetrahydropyran is an important structural skeleton of bioactive natural products. A facile synthesis of cis‐2,6‐disubstituted‐3,6‐dihydropyrans as cis‐2,6‐tetrahydropyran precursors has been achieved in high regio‐ and stereoselectivity with high yields. This reaction involves a palladium‐catalyzed decarboxylative allylation of various 3,4‐dihydro‐2H‐pyran substrates. Extending this reaction to 1,2‐unsaturated carbohydrates allowed the achievement of challenging β‐C‐glycosylation. Based on this methodology, the total syntheses of (±)‐centrolobine and (+)‐decytospolides A and B were achieved in concise steps and overall high yields.