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含偶氮苯的咔唑类双功能光折变聚合物的合成及表征 总被引:1,自引:1,他引:1
通过后重氮偶合方法制备了一系列不同生色团含量的咔唑类双功能光折变聚合物,并用IR、^1H-NMR、UV-vis、DSC以及GPC等对聚合物进行了分析和表征。IR和UV-vis谱图显示偶氮苯基团已接到咔唑环上。UV-vis结果表明:反应时间对该反应的影响非常大,当反应时间从6h增加到60h时,聚合物中生色团的含量从13.5%升高到66.7%。GPC结果显示后重氮偶合法比常规方法得到的该类聚合物的分子量明显提高。DSC结果显示聚合物的玻璃化转变温度随偶氮苯含量的增加而升高。 相似文献
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聚苯乙烯基偶氮聚合物的合成研究 总被引:4,自引:0,他引:4
改进了聚苯乙烯的硝化、还原、重氮化和偶合反应路线 (NRDC) ,使每步反应都得到很高的产率 ,并利用大分子重氮盐 (MDS)分别与苯胺、N 烃基苯胺和酚等三类化合物偶合 ,得到相应的聚苯乙烯基偶氮聚合物 .核磁共振分析结果证明了产物的高偶联率 .通过对大分子重氮盐热稳定性的研究 ,发现偶合反应之后需要一步加热反应以消除残余重氮基团 .还研究了这些聚合物的紫外 可见吸收光谱性质 ,氨 (胺 )基偶氮产物的水溶液表现出了明显的pH敏感性 相似文献
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系统介绍了核磁共振氢谱中卫星峰的种类、组成和分析方法。卫星峰中包含了大量的低丰度自旋核和氢核,特别是13C-1H间的精细偶合信息。这些偶合中1J偶合最为常见,该偶合常数和C-H之间的化学环境息息相连。因此,若能把握这类信息,对于结构解析是很大一个助力。本文详细介绍了几例卫星峰的分析过程及其在大学化学课程教学和科研中的应用,特别是用于理解超共轭效应和立体电子效应。 相似文献
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重氮感光材料是非银感光体系研制中的一个分文。六十年代以来,重氮技术发展很快。重氮复制法的基本原理是:涂布在纸基或塑料片上的重氮感光材料,在短波紫外光的照射下,重氮化合物见光分解,并放出氮气。曝光后,感光部位的重氮化合物分解而消失。未感光部位的重氮化合物与偶联 相似文献
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本文探讨了重氮片的主要组份——偶合剂、重氮化合物和成膜剂对重氮片颜色的影响.试验结果说明:不同芳核结构的偶合剂以及在重氮盐中引入不同芳核和取代基对重氮片的影像颜色影响较大,另外,重氮片所用的成膜剂对其影像颜色也有影响. 相似文献
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本文通过GC/MS谱分析研究了重氮负性胶片中醚类封闭偶合剂的解封历程。测定了二种胶片的紫外-可见吸收光谱。讨论了感光特性曲线。结果表明在重氮负片成像过程中使用封闭偶合剂MEM-α-萘醚的重氮胶片由酸催化解封主要是分子内重排。而使用叔丁基-α-萘醚的胶片由酸催化解封主要是脱除保护基的断裂产物。二种胶片相比,前者的感光度比较高,而且它的图像片中染料的吸收峰向长波移动。 相似文献
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Azo compounds are very important in organic chemistry. In resent years, some notoworthy studies show that azobenzene derivatives possess very good optic remembering and photoelectric properties, optical switching and image storage by means of azobenzene liquid crystal film.1,2 We have reported some new methods for the Azo compounds3. In this paper, We describe a new oxidation system KCIO3/H2SO4 catalyzed by FeSO4 to synthesis diazo compounds (ArN=NCON=NAr) in short time and good yield for the first time. 相似文献
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Yamaki SB Andrade AA Mendonça CR Oliveira ON Atvars TD 《Journal of colloid and interface science》2005,283(2):464-471
A morphological analysis is presented for Langmuir films of the diazo dyes Sudan 4 (S4), Sudan 3 (S3), and Sudan red (SR), using Brewster angle microscopy. Stable nonmonomolecular structures are formed at the air-water interface denoted as a plateau in the pressure-area isotherms. Monolayer domains are evident by the contrastless image even before the pressure onset, which grow in size until it reached a condensed monolayer. This behavior resembles that of Langmuir films from simple aromatic fatty acids. Films from all the azo dyes display similar features, according to the surface potential isotherms and in situ polarized UV/vis spectroscopy except for the larger area per molecule occupied by S4 and SR. This is attributed to the presence of CH(3) groups that cause steric hindrance modifying the organization of diazo dye molecules at the air-water interface. UV/vis polarized absorption spectroscopy showed preferential orientation of S4 and S3 on the water surface, while SR molecules lie isotropically. For these three diazo dyes, film absorption was negligible at very large areas per molecule, becoming nonzero only at a critical area coinciding with the onset of surface potential. The critical area is ascribed to the formation of a H-bonded network between water molecules and diazo dye headgroups. 相似文献
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A series of diazo carbonyl compounds bearing different substituents have been prepared in order to investigate the steric effect in 1,2-migration reaction of rhodium(II) carbene. Through the investigation on the diazo decomposition of these compounds with Rh2(OAc)4, it was found that the steric effect could dramatically influence the migratory aptitude. In many cases, the steric effect could override the inherent electronic effect of the substituent. 相似文献
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The reaction scope of trifluoromethanesulfonyl azide in diazo transfer reactions was extended to include the preparation of α-cyano-α-diazo-carbonyls, phenyl sulfonyl diazoacetophenone and diethyl diazomalonate in high yields. The effect of the bases used in the diazo transfer reactions were found to have a dramatic influence on the success of the reaction with pyridine being the base of choice. 相似文献
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Rosella M. OMahony Caoimhe M. Broderick Denis Lynch Stuart G. Collins Anita R. Maguire 《Tetrahedron letters》2019,60(1):35-39
Herein, we report the preparation and use of m-carboxybenzenesulfonyl azide as a diazo transfer reagent. This compound is an inexpensive and potentially scalable alternative to many of the diazo transfer reagents currently available, most of which have hazards associated with their use. Its usefulness and suitability as a diazo transfer reagent was assessed on the basis of cost, safety and its effectiveness in diazo transfer to a variety of different substrates. 相似文献
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Dr. Pauline Rullière Guillaume Benoit Emmanuelle M. D. Allouche Prof. André B. Charette 《Angewandte Chemie (International ed. in English)》2018,57(20):5777-5782
Despite the high synthetic potential of nonstabilized diazo compounds, their utilization has always been hampered by stability, toxicity, and safety issues. The present method opens up access to the most reactive nonstabilized diazoalkanes. Among diazo compounds, nonstabilized alkyl diazo compounds are the least represented because of their propensity to degrade during preparation. The continuous flow oxidation process of hydrazones on a silver oxide column afforded an output stream of base‐ and metal‐free pure diazo solution in dichloromethane. Starting from innocuous ketones and aldehydes, this methodology allows the production of a broad range of unprecedented diazoalkanes compounds in excellent yields, while highlighting their synthetic potential and the possibility of safe large‐scale diazo production. 相似文献