Fabrication, Characterization and Electrocatalysis of an Ordered Carbon Nanotube Electrode

A method for fabrication of ordered carbon nanotube (CNT) film,which was template-synthesized within the highly ordered pores of a commercially available alumina template membrane,modified glassy carbon(CNT/GC) electrode was established.The CNT/GC electrode showed excellent electrocatalytic activity toward dopamine electrochemical reaction without introducing any electrochemically active group into CNT film or activating any electrochemically active group into CNT film or activating the electrode electrochemically.DA undergoes ideal reversible electrochemical reaction on CNT/GC electrode at low scan rate(≤20mV/s) with an excellent reproducibility and stability.The CNT/GC electrode might be used in biosensors because the highly ordered CNT may present a steric effect on more efficient redox reactions of biomolecules.     

Synergistic extraction of uranium(VI) with mixtures of bis(hexylsulfinyl)ethane (BHxSE) and petroleum sulfoxides (PSO)

The synergistic extraction of uranium(VI) from aqueous nitric acid solution with mixtures of bis(hexylsulfinyl)ethane (BHxSE) and petroleum sulfoxides (PSO) in 1,1,2,2-tetrachloroethane was studied. It has been found that the maximum synergistic extraction effect occurs when the molar ratio of PSO to BHxSE is close to 1. The composition of the complex of synergistic extraction was estimated as UO₂(NO₃)₂ ^.BHxSE^.PSO. The formation constant of the complex was equal to K_BP = 4.23±0.03. The effects of extractant, nitric acid, salting-out agent, and complex anion concentrations and temperature on the extraction equilibrium of uranium(VI) were also studied.     

Bis­(tetra­phenyl­phospho­nium) (μ‐tetra­thio­tungstenio‐κ4S,S′:S′′:S′′′)­bis­[(cyano‐κC)­cuprate](2–) aceto­nitrile solvate monohydrate

The reaction of CuCN and KCN with (NH₄)₂[WS₄] followed by cation exchange with PPh₄Br produced the title compound, (C₂₄H₂₀P)₂[Cu₂WS₄(CN)₂]·CH₃CN·H₂O or (PPh₄)₂[(NC)Cu(μ‐S)₂W(μ‐S)₂Cu(CN)]·MeCN·H₂O. In the structure of the dianion, [(NC)Cu(μ‐S)₂W(μ‐S)₂Cu(CN)]²⁻, the WS₄ moiety acts as a bidentate ligand that binds two CuCN groups, thus forming a slightly bent WCu₂ core with approximate D_2d symmetry. The W—Cu distances are in the range 2.6463 (6)–2.6545 (6) Å.     

Magnesium boride sintered as high-energy fuel

Boron was chosen as fuel owing to its excellent thermodynamic values for combustion. The difficulty of the boron in combustion is the formation of a surface oxide layer, which postpones the combustion process, reducing the performance of the rocket engine. In this paper, magnesium boride was sintered as high-energy fuel as a substitute for boron. The combustion heat and efficiency of magnesium boride and boron were determined using oxygen bomb calorimeter. The combustion characteristics of magnesium boride were investigated by thermal analysis, chemical analysis, XRD, and EDS. Results show that the combustion performance of magnesium boride are better than that of amorphous boron in oxygenated environments. The evaporation of magnesium in magnesium boride combustion process prevent the formation of a closed oxide layer, leading to higher combustion efficiency.     

新颖无限三股螺旋钴配位聚合物{[Co(4,4''''-bipyridine)(4,4''''azobispyridine)_2(NCS)_2]·H_2O}_n的合成、结构和性质的研究(英文)

0IntroductionThereisagreatcurrentinterestforthecrystalengineeringofcoordinationframeworks犤1,2犦,notonlybecauseoftheirpotentialapplicationsaszeolite-likematerialsinmolecularselection,ionexchange,andcatalysis,butalsobecauseoftheirintriguingvarietyofarchitecturesandnewtopologies.Uptonow,themostimportantdrivingforcesincrystalengineeringarecoordinationbondingandhydrogenbondinginteract-ion犤3～5犦.Theuniquedirectionality,strength,andcom-plementaryofnon-covalenthydrogenandcoordinatedbondingplayanimp…     

Unsymmetrically substituted ethane as a new and efficient initiator for the polymerization of methyl methacrylate and styrene

In this paper, we present a compound, 2,3-diphenyl butyronitrile (DPBN), which can be used as a new and efficient radical initiator for the polymerization of methyl methacrylate (MMA) and styrene (St). Very different from other compounds as a carbon-carbon initiator, DPBN is an unsymmetrically substituted ethane and works with high initiation reactivity at lower temperatures. This new compound as an initiator exhibits various advantages, such as easy preparation, high initiation reactivity, safe use and storage, and convenient handling.     

New catalytic effect of thiourea on the oxidative cyanation of N-aryltetrahydroisoquinolines

Thiourea itself has been introduced as a mild and efficient organocatalyst for the oxidative α -cyanation of N-aryltetrahydroisoquinolines (THIQs) with trimethylsilyl cyanide (TMSCN), giving the corresponding products in good to excellent yields. Experimental investigations demonstrated that thiourea acts as a radical initiator by abstracting hydroxyl radical (OH) from tert-butyl hydroperoxide (TBHP) directly instead of non-covalent hydrogen bondings (H-bondings) activation. The use of thiourea as a radical initiator offers a new avenue for innovative chemical transformations in organocatalyzed radical chemistry.     

A highly sensitive and selective fluorescent probe for Fe3+ containing two rhodamine B and thiocarbonyl moieties and its application to live cell imaging

A novel turn-on rhodamine B-based fluorescent chemosensor (RBCS) was designed and synthesized by reacting N-(rhodamine B)lactam-1,2-ethylenediamine and carbon disulfide. Upon addition of Fe³⁺ in EtOH/H₂O solution (2:1, v/v, HEPES buffer, 0.6?mM, pH 7.20), the RBCS displayed a significant fluorescence enhancement at 582?nm and a dramatic color change from colorless to pink, which can be detected by the naked eye. Significantly, the RBCS exhibited a highly selective and sensitive ability toward Fe³⁺. The detection limit of the probe was 2.05?×?10^?7?M. Job's plot indicated the formation of 1:1 complex between the RBCS and Fe³⁺. Moreover, the practical use of the RBCS is demonstrated by its application in the detection of Fe³⁺ in HeLa cells.     

Highly Efficient and Diastereoselective Construction of Tricyclic Pyrrolidine‐Fused Benzo[b]thiophene 1,1‐dioxide Derivatives via 1,3‐Dipolar [3 + 2] Cycloaddition

A rapid and highly efficient 1,3‐dipolar [3 + 2] cycloaddition of nonstabilized azomethine ylides generated in situ with benzo[b]thiophene 1,1‐dioxides as the dipolarophiles has been developed. The efficient method affords tricyclic pyrrolidine‐fused benzo[b]thiophene 1,1‐dioxide derivatives in high to excellent yields (up to 99%) with excellent diastereoselectivities (up to >25:1 dr) under mild reaction conditions. The structure of a typical product was confirmed by X‐ray crystallography.     

Solvent‐free ring‐opening polymerization of lactones with hydrogen‐bonding bisurea catalyst

Development of effective organocatalysts for the living ring‐opening polymerization (ROP) of lactones is highly desired for the preparation of biocompatible and biodegradable polyesters with controlled microstructures and physical properties. Herein, a new class of hydrogen‐bond donating bisurea catalysts is reported for the ROP of lactones under solvent‐free conditions. ROP of lactones mediated by the bisurea/7‐methyl‐1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (MTBD) catalyst exhibits a living/controlled manner, affording the polymers and copolymers with the well‐defined structure, predictable molecular weight, narrow molecular weight distribution, and high selectivity for monomer at low catalyst loadings at ambient temperature. The possible mechanism of bisurea/MTBD‐catalyzed ROP of lactones is proposed, in which the bisurea activates the carbonyl group of lactones while MTBD facilitates the nucleophilic attack of the initiating/propagating alcohol by hydrogen bonding. Moreover, the poly(ε‐caprolactone‐co‐δ‐valerolactone) [P(CL‐co‐VL)] random copolymers with various compositions were synthesized using the bisurea/MTBD catalyst. The measurements of thermal properties and crystalline structure demonstrate that the CL and VL units are cocrystallized in the crystalline phase of P(CL‐co‐VL) copolymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 90–100