3‐(Diphenylphosphino)propanoic acid: an efficient ligand for the Pd/Cu‐catalyzed homo‐coupling of terminal alkynes in the presence of oxygen at room temperature

A simple, yet efficient system for PdCl₂/CuI to catalyze the homo‐coupling reactions of various terminal alkynes has been developed using 3‐(diphenylphosphino)propanoic acid as ligand in the presence of oxygen. The alkynes, including aromatic, heteroaromatic and aliphatic alkynes, were transformed at room temperature into the corresponding 1,3‐diynes in moderate to excellent yields. The turnover number was up to 1.04 × 10³. Copyright © 2015 John Wiley & Sons, Ltd.     

Silver nanoparticles capped with chalcon carboxylic acid as a probe for colorimetric determination of cadmium(II)

Microchimica Acta - The authors describe a selective and sensitive method for the colorimetric determination of Cd(II) by using silver nanoparticles capped with chalcone carboxylic acid (CCA) as an...     

Synthesis of symmetrical terphenyl derivatives by PdCl2-catalyzed Suzuki–Miyaura reaction of dibromobenzene using 3-(diphenylphosphino)propanoic acid as a ligand

A simple and efficient catalytic system for PdCl₂ catalyzing the Suzuki–Miyaura reaction of dibromobenzene and arylboronic acid has been developed by using 3-(diphenylphosphino)propanoic acid as a ligand in dimethylsulfoxide at 100 °C. Using this method, a series of symmetrical terphenyl derivatives were obtained with remarkably good yields, up to 93%.     

ON THE BOUNDEDNESS OF A CLASS OF NONLINEAR DYNAMIC EQUATIONS OF THE THIRD ORDER

In this paper, a modified nonlinear dynamic inequality on time scales is used to study the boundedness of a class of nonlinear third-order dynamic equations on time scales. These theorems contain as special cases results for dynamic differential equations, difference equations and $q$-difference equations.     

Comparison and validation of methods for estimating heat generation rate of large-format lithium-ion batteries

The heat generation rate of a large-format 25 Ah lithium-ion battery is studied through estimating each term of the Bernardi model. The term for the reversible heat is estimated from the entropy coefficient and compared with the result from the calorimetric method. The term for the irreversible heat is estimated from the intermittent current method, the V–I characteristics method and a newly developed energy method. Using the obtained heat generation rates, the average cell temperature rise under 1C charge/discharge is calculated and validated against the results measured in an accelerating rate calorimeter (ARC). It is found that the intermittent current method with an appropriate interval and the V–I characteristics method using a pouch cell yield close agreement, while the energy method is less accurate. A number of techniques are found to be effective in circumventing the difficulties encountered in estimating the heat generation rate for large-format lithium-ion batteries. A pouch cell, using the same electrode as the 25 Ah cell but with much reduced capacity (288 mAh), is employed to avoid the significant temperature rise in the V–I characteristics method. The first-order inertial system is utilized to correct the delay in the surface temperature rise relative to the internal heat generation. Twelve thermocouples are used to account for the temperature distribution.     

Effects of constant voltage at low potential on the formation of LiMnO2/graphite lithium ion battery

The effect of formation protocol including different constant voltage points at low potential, different constant voltage time, and different current were studied in this paper. The electrochemical impedance spectroscopy and stored and cycle performance tests were used to verify the parameter of different formation protocols. The results show that the resistance of solid electrolyte interphase film R _f drops during the whole potential range except 3.1 to 3.5 V and the diffusion coefficient P _f which represents the uniformity of anode electrode surface decreases only at this potential range. The effects of different constant voltage points at 3.1 to 3.5 V were studied to increase the uniformity of anode electrode surface and decrease the resistance of the SEI film. The film is more stable at 3.3 V constant voltage than other potentials, and a constant voltage 60 min is enough to form a uniformity and compact passivation layer. With the constant voltage time extending, the P _f decreases. When the formation current to constant potential is increased, the film is more loose (or porous) and less adhesive. The formation protocol of 0.01 C to 3.3 V constant voltage 60 min shows the best cycling performance, and formation protocol of no constant voltage shows the worst cycling performance. Considering the time and energy consumption, the formation protocol of 0.05 C to 3.3-V constant voltage 60 min is the best.     

Enzymatic biosensors based on the use of metal oxide nanoparticles

Over the past decades, various techniques have been developed to obtain materials at a nanoscale level to design biosensors with high sensitivity, selectivity and efficiency. Metal oxide nanoparticles (MONPs) are of particular interests and have received much attention because of their unique physical, chemical and catalytic properties. This review summarizes the progress made in enzymatic biosensors based on the use of MONPs. Synthetic methods, strategies for immobilization, and the functions of MONPs in enzymatic biosensing systems are reviewed and discussed. The article is subdivided into sections on enzymatic biosensors based on (a) zinc oxide nanoparticles, (b) titanium oxide nanoparticles, (c) iron oxide nanoparticles, and (d) other metal oxide nanoparticles. While substantial advances have been made in MONPs-based enzymatic biosensors, their applications to real samples still lie ahead because issues such as reproducibility and sensor stability have to be solved. The article contains 256 references.

Effect of Different Ionic Liquids on 5-Hydroxymethylfurfural Preparation from Glucose in DMA over AlCl3: Experimental and Theoretical Study

In this work, effect of different ionic liquids (ILs) on 5‐hydroxymethylfurfural (HMF) preparation from glucose in N,N‐dimethylacetamide (DMA) over AlCl₃ was revealed by a combined experimental and computational study. ILs used as cocatalysts in this work included N‐methyl‐2‐pyrrolidone hydrogen sulfate ([NMP]HSO₄), N‐methyl‐2‐pyrrolidone methyl sulfate ([NMP]CH₃SO₃), N‐methyl‐2‐pyrrolidone chlorine ([NMP]Cl) and N‐methyl‐2‐pyrrolidone bromide ([NMP]Br) which were endowed with the same cation but different anions. According to the conclusion that fructose was intermediate product from glucose to HMF, we found fructose was transformed to more by‐products by [NMP]HSO₄, making HMF yield decline significantly when glucose was treated as substrate. Neither glucose nor fructose could be converted by [NMP]CH₃SO₃ efficiently, leading to its no influence on glucose conversion to HMF. [NMP]Br had a higher selectivity for HMF from fructose than [NMP]Cl and AlCl₃. Besides, Al³⁺ preferred to combine with Br^?, slightly decreasing both the overall free energy barrier for glucose isomerization and activation barrier for H‐shift at 393.15 K. So a high HMF yield of 57% was obtained from glucose catalyzed by AlCl₃ together with [NMP]Br under mild conditions.     

3-(3-吲哚基)-5-吡唑甲酰胺的合成及抑菌活性

本文以3-乙酰吲哚、草酸二乙酯、水合肼等为原料,经缩合、环化、水解反应制备3-(3-吲哚基)吡唑-5-甲酸,后者再与苄胺或2-苯乙胺在EDC-BTOH催化下合成了一系列N-取代苄基-3-(3-吲哚基)吡唑-5-甲酰胺和N-(2-取代苯基乙基)-3-(3-吲哚基)吡唑-5-甲酰胺。采用平板计数法测试了化合物对大肠杆菌和金黄色葡萄球菌的抑制活性,结果表明,在浓度为80 μg/mL时部分化合物有较高的抑菌活性。     

SYNTHESIS AND FLUORESCENCE STUDY OF SELF-AGGREGATION PROCESS IN AQUEOUS SOLUTION OF HYDROPHOBILIZED POLYSACCHARIDE

1.INTRODUCTIONMolecularself-assemblyorself-aggregationisthespontaneousassociationofmoleculesunderequilibriumconditionsintostable,structurallywell-definedaggregationsjoinedbynoncovalentbonds.Theself-aggregationofmoleculesleadstosupramolecularsystemsandisresponsiblefortheirfunctions.Recently,self-assemblyoraggregationofpolymeramphiphilesisofgrowinginterestwithrespecttobiologicalimportanceandpharmaceuticalorbiotechnologicalapplication.Solutionpropertiesofvariousblockcopolymerorself-aggregate…