含3-三氟甲基的均三唑并[3,4-b]-1,3,4-噻二唑类化合物的合成

以 3-三氟甲基 - 4-氨基 - 5 -巯基 - 1 ,2 ,4-三唑为原料 ,分别与 2 - ,3- ,4-吡啶甲酸及α-萘乙酸在 POCl3催化下反应 ,制得 4种新的 3-三氟甲基 - 6-取代均三唑并 [3,4- b]- 1 ,3,4-噻二唑( 3a～ 3d) ,并利用 EA,IR,1H NMR等确定了其结构     

Synthesis and characterization of novel polyimides containing triazoles units in the main chain by click chemistry

In this study, some polyimides containing triazoles units in the main chain was prepared from the polymerization of dialkynes including imide linkages and diazides in the presence of Cu (I) catalyst in yield of 76.2–87.6%, with inherent viscosity of 0.37–0.53 dL g^?1. The obtained polymers are soluble in polar aprotic solvents such as N,N‐dimethyformamide (DMF), N,N‐dimethyacetamide (DMAc), dimethyl sulfoxide (DMSO), and N‐methyl‐2‐pyrrolidone (NMP). These polymers were characterized using FT‐IR, ¹H‐NMR, and elemental analysis techniques. Their thermal stability was evaluated with thermogravimetric (TGA) analysis and differential scanning calorimetry (DSC) techniques under a nitrogen atmosphere which is indicative of their good thermal stability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The effect of nitrogen and sulphur compounds on extreme pressure lubrication

This paper reports the synthesis of hydroxyheptadecyl-substituted-1,3,4-thiadiazoles and mercapto-1,2,4-triazoles and the evaluation of extreme pressure activity of their admixtures (0.5% and 1% w/ v) with a paraffinic oil in a four-ball test. Alloy steel bearing balls of 12.7 mm diameter were used as test specimens. All the additives exhibited good activity in reducing wear and increasing the values of mean Hertz load (MHL) and flash temperature parameter (FTP) as compared to the base fluid. The presence of p-methoxy- and p-chloro- groups in the thiadiazole and mercapto triazole rings has been found to enhance the activity of these additives. Scanning Auger Electron Spectroscopy surface studies were conducted to analyse the additive-metal interaction.     

Sequential Functionalization of the O?H and C(sp2)?O Bonds of Tropolones by Alkynes and N‐Sulfonyl Azides

Sequential copper‐catalyzed [3+2] cycloaddition, rhodium‐catalyzed O H insertion, intramolecular 1,8‐addition, and rearrangement starting from 1‐alkynes, N‐sulfonyl azides, and tropolones is demonstrated for the synthesis of the 2‐functionalized aminotropones in one pot. These results indicate that sequential functionalization of O H and C(sp²) O bonds smoothly occurs in the C(sp²) O H bonds of tropolone

     

联唑类含能化合物及其含能离子盐研究进展

联唑类含能化合物及其含能离子盐是近年发展起来的一类新型含能材料,具有高氮含量、高生成焓、高爆轰性能和相对钝感等特性,在新型炸药、低特征信号推进剂、气体发生剂、低烟或无烟烟火等领域有着广泛的应用前景。综述了有关联-1,2,4-三唑、联四唑和5-(1,2,4-三唑)四唑等联唑类含能化合物及其含能离子盐的最新合成研究成果,并对部分化合物的物化性能进行了阐述。认为下一步的工作重点为研究富氮阳离子的引入对联唑类含能化合物感度和爆轰性能的影响,合成出综合性能更好的联唑类含能化合物。设计了9种新型联唑类含能化合物,并利用量子化学方法对其性能进行预估。     

Corrosion inhibition by fatty acid triazoles for mild steel in formic acid

5-Heptadec-8-enyl-4-phenyl-4H–[1,2,4] triazole-3-thiol (HPTT), 4-phenyl-5-undecyl-4H–[1,2,4] triazole-3-thiol (PUTT), and 5-dec-9-enyl-4-phenyl-4H–[1,2,4] triazole-3-thiol (DPTT) were synthesized and their influence on the inhibition of corrosion of mild steel in 20% formic acid was investigated by weight loss and potentiodynamic polarization techniques. The inhibition efficiency of these compounds was found to vary with their nature and concentration, temperature and immersion time. The values of activation energy and free energy of adsorption of the triazoles were calculated to investigate the mechanism of corrosion inhibition. Good inhibition efficiency (>90%) was found even at lower concentration (i.e., 25 ppm) in acid solution. The adsorption on mild steel surfaces was found to obey Temkin's adsorption isotherm. Potentiodynamic polarization results revealed that the compounds studied are mixed type inhibitors. Electrochemical impedance spectroscopy was also used to investigate the mechanism of the corrosion inhibition.     

Residue analysis of 500 high priority pesticides: Better by GC–MS or LC–MS/MS?

This overview evaluates the capabilities of mass spectrometry (MS) in combination with gas chromatography (GC) and liquid chromatography (LC) for the determination of a multitude of pesticides. The selection of pesticides for this assessment is based on the status of production, the existence of regulations on maximum residue levels in food, and the frequency of residue detection. GC-MS with electron impact (EI) ionization and the combination of LC with tandem mass spectrometers (LC-MS/MS) using electrospray ionization (ESI) are identified as techniques most often applied in multi-residue methods for pesticides at present. Therefore, applicability and sensitivity obtained with GC-EI-MS and LC-ESI-MS/MS is individually compared for each of the selected pesticides. Only for one substance class only, the organochlorine pesticides, GC-MS achieves better performance. For all other classes of pesticides, the assessment shows a wider scope and better sensitivity if detection is based on LC-MS.     

3,5-bis(n-Hydroxyphenyl)-4-amino-1,2,4-triazoles and 3,5-bis(n-aminophenyl)-4-amino-1,2,4-triazoles: a new class of corrosion inhibitors for mild steel in 1m HCl medium

A new class of corrosion inhibitors, namely, 3,5-bis(n-hydroxyphenyl)-4-amino-1,2,4-triazoles and 3,5-bis(n-aminophenyl)-4-amino-1,2,4-triazoles which have been labelled n-HPAT and n-APAT has been synthesized. The influence of aminotriazoles on the corrosion of mild steel in 1m HCl has been studied using weight loss and electrochemical impedance spectroscopy. Results obtained show that these compounds are very good anodic inhibitors. The adsorption of these aminotriazoles is found to obey Langmuir adsorption isotherm.