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101.
We describe a convenient method for the synthesis of 1,2-disubstituted acetylenes via a cross-coupling reaction of (bromoethynyl)benzene with Grignard reagents. The reaction of (bromoethynyl)benzene (1 mmol) with Grignard reagent (1.3 mmol) mediated by NiCl2 (4 mol%) and (p-CH3Ph)3P (8 mol%) in THF could produce 1,2-disubstituted acetylenes in good yields at room temperature. 相似文献
102.
Promotion Effect of Bismuth on Nickel Electrodeposition and Its Electrocatalysis to Glucose Oxidation 下载免费PDF全文
Metallic Bi and Ni were co‐deposited onto the surface of glass carbon electrode (GCE) from the electrolyte solution containing their respective nitrate to fabricate a Bi/Ni alloy modified GCE (Bi/Ni‐GCE). The purpose is to study the influence of Bi3+ on the deposition of Ni and that of deposited Bi on the electrocatalytic performance of Ni to glucose in alkali solution. The results show that both redox signal of Ni(OH)2/NiOOH and Ni(OH)2/NiOOH mediated electrocatalysis to glucose is remarkably increased in the presence of Bi. It seems that there is a synergistic effect between Bi and Ni on each other’s redox electrochemistry. It’s possible that the firstly deposited Bi on GCE surface helps to the following nucleation and growth of Ni, leading to the deposition of more metallic Ni on GCE surface. An extremely attractive feature of Bi/Ni‐GCE is reflected by the fast response time to the electrocatalytic oxidation of glucose. The electrode nearly responses immediately after glucose is added and it reaches a steady‐state level within only 2 seconds, demonstrating a good electrocatalytic property of Bi/Ni‐GCE. The calibration plot is linear over the wide concentration range of 0–5.8 mM with a sensitivity of 33.96 µA/mM and a correlation coefficient of 0.9985. The detection limit of the glucose was found to be 0.59 µM at a signal‐to‐noise ratio of 3. The fabricated Bi/Ni‐GCE was successfully employed to analyze the glucose level in blood samples, exhibiting high accuracy, strong resistance against inference and good reliability in the practical applications. 相似文献
103.
104.
A procedure for copper and nickel determination in scalp hair by solid sampling electrothermal atomic absorption spectrometric method was described. The hair samples (0.02 to 0.4 mg) were inserted directly on the platforms of solid sampling autosampler. The effects of pyrolysis temperature, atomization temperature, the amount of sample as well as addition of a modifier (Pd/Mg) and/or auxiliary digesting agents (hydrogen peroxide and nitric acid) and/or a surfactant (Triton X-100) on the determination of copper and nickel by solid sampling atomic absorption spectrometry were investigated. After optimization of parameters, the average recoveries of copper in two different certified reference hair samples were 105.7 and 97.6%. The recoveries of nickel in the both certified reference hair samples were in 95.2 and 96.4%. The limits of detection (3σ, N = 10) for copper and nickel were 22 ng/g and 35 ng/g, respectively. Heterogenous distribution of analyte in microscale for segmental analysis could be determined which is important to know that analyte quantity and time of poisoning of a person was exposed. For this purpose, 0.5 cm of pieces were cut along one or a few close strands and analyzed by solid sampling. This process could not be performed by wet-digestion method because 50 mg of sample is needed each time. Finally, the method was applied for the determination of copper and nickel concentrations in the hairs of different persons. 相似文献
105.
106.
The glassy carbon electrode was modified with a nickel pentacyanonitrosylferrate film by electrodeposition of Ni and subsequent derivatization with NaPCNF. The film was characterized by XPS and electrochemical methods. Cyclic voltammetry of the NiPCNF onto the GC shows a redox couple (FeIII/FeII) with E°′ of 538 mV (Ipa/Ipc around 1) and ΔEp of 93 mV in 0.5 mol L?1 KNO3, with a diffusion‐controlled process. There was a decrease of anodic peak currents of the film in the presence of sulfide and 2‐propanethiol due to a precipitation reaction on the film surface by nucleophilic attack. 相似文献
107.
Dr. Weinan Xing Dr. Shengming Yin Dr. Wenguang Tu Dr. Guanyu Liu Dr. Shuyang Wu Dr. Haojing Wang Prof. Markus Kraft Dr. Guangyu Wu Prof. Rong Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(3):1187-1191
A simple solvent ligation effect was successfully used to disrupt the growth of a model compound, Fe[(OH)(O3P(CH2)2CO2H)]⋅H2O (MIL-37), into an extended 2D structure by replacing water with dimethylformamide (DMF) as the solvent during the synthesis. Owing to the lack of −OH group, which provides the corner-sharing (binding) oxygen atoms for the octahedra, an amorphous and porous structure is formed. When Fe3+ is partially replaced by Ni2+, the amorphous structure remains and the resultant binary metal catalyst displays excellent photocatalytic oxygen evolution activity with almost 100 % yield achieved under visible light irradiation using [Ru(bpy)3]2+ as the photosensitizer. This study opens up new possibilities of using the simple solvent effect to synthesize high surface area metal phosphonates for catalytic and other applications. 相似文献
108.
5-Amino-4-cyano-1-(hetero)arylimidazoles 1 are prepared by reaction of N-(hetero)arylformimidoethylesters 2 with 2-aminomalodinitrile in acetic acid. 相似文献
109.
A series of nickel halides bearing 2,4-di-t-butyl-6-(quinolin-8-yliminomethyl) phenolate ligands was synthesized and characterized by IR spectroscopy and elemental analysis.Molecular structures of C1(R = H,X = Br) and C2(R = H,X = Cl) were further confirmed by single-crystal X-ray crystallographic studies,and revealed a distorted square planar geometry at nickel.Upon activation with diethylaluminum chloride(Et 2 AlCl),all nickel pre-catalysts displayed good catalytic activity [up to 9.3 × 10 5 g mol 1(Ni) h 1 ] for ethylene oligomerization with major dimerization.In the presence of methylaluminoxane(MAO),the nickel complex C1 was capable of ethylene polymerization under 3 MPa,and produced polyethylene products with narrow polydispersity(1.16 1.73) and molecular weights in the range of 2.6 4.95 kg/mol. 相似文献
110.
以多孔Al2O3陶瓷为基体材料, 采用浸渍法担载NiO后用2B铅笔修饰NiO/Al2O3表面, 通过化学镀法沉积约5 μm厚的金属钯, 还原后成功制得Pd/Pencil/Ni/Al2O3膜. 为进行对比, 还制备了未担载镍的Pd/Pencil/Al2O3膜. 膜的表面和断面形貌分别采用扫描电镜和金相显微镜观测, 膜的透氢动力学通过H2/N2单气体法测试, 并以成分为H2 77.8%, CO 5.2%, CO2 13.5%和CH4 3.5%的原料氢测定了膜的氢分离效果. 结果表明, 未载镍的Pd/Pencil/Al2O3膜只具有氢分离作用, 而Pd/Pencil/Ni/Al2O3膜还可以有效地将钯膜泄漏的CO和CO2转化为甲烷, 因而成为双功能型钯膜. 这种双功能膜尤其适用于面向质子交换膜燃料电池(PEMFC)的氢气分离, 既有效解决了PEMFC对氢燃料中CO格外敏感的难题, 又提高了对钯膜缺陷的容忍度, 因而延长了钯膜的使用寿命. 相似文献