亲电取代的相转移催化反应研究——咔唑型分散染料的合成

本文应用磺酸阴离子化合物作为相转移催化剂，以邻氯对硝基苯胺，２，４，６－三氯苯胺为重氮组份，咔唑和Ｎ－乙基咔唑为偶合组成，合成了四种咔唑型分散染料，具有一定的实用价值。     

亲电取代的相转移催化反应研究－咔唑型分散染料的合成

本文应用碳酸阴离子化合物作为相转移催化剂，以邻氯对硝基苯胺，２，４，６－三氯苯胺为重氮组份，咔唑和Ｎ－乙基咔唑为偶合组份，合成了四种咔唑型分散染料，具有一定的实用价值。     

甲基丙烯酸乙基咔唑酯的合成与表征

以新型光电材料的一种原料羟乙基咔唑和甲基丙烯酸甲酯为原料,对甲苯磺酸为催化剂,对苯二酚为阻聚剂,采用酯交换法合成甲基丙烯酸乙基咔唑酯。采用紫外光谱(UV-vis)傅立叶变换红外光谱(FT-IR)对产物的结构进行了表征。     

新型近红外咔唑吲哚类硼酸酯荧光探针的合成与表征

以咔唑为起始原料,经过与亲电取代反应、Vilsmeier反应、溴化反应以及与双联频哪醇硼酸酯的偶联反应,合成了N-乙基咔唑-3-甲醛-6-苯硼酸酯,以合成的N-乙基咔唑-3-甲醛-6-苯硼酸酯,以合成的乙基取代咔唑硼酸,以合成的乙基取代咔唑硼酸酯醛与1,2,3,3-四甲基-3H-吲哚碘化物缩合,合成了一种新型近红外咔唑吲哚啉类硼酸酯荧光探针,其结构经过1H NMR,IR进行了表征。     

相转移催化法合成N-乙基咔唑的研究

以咔唑和溴乙烷为原料,在季铵盐相转移催化剂的条件下合成了N-乙基咔唑,考察了温度、催化剂种类、催化剂用量以及投料比等因素对N-乙基咔唑收率的影响,确定了最佳的催化剂及工艺条件。结果表明,四丁基溴化铵具有最佳的催化活性,在适宜反应条件下,N-乙基咔唑的收率可达97%。     

甲基丙烯酸乙基咔唑酯／N-乙烯基咔唑共聚物的研制

以甲基丙烯酸乙基咔唑酯、N-乙烯基咔唑为原料,以偶氮二异丁腈为引发剂,采用共聚合方法合成甲基丙烯酸乙基咔唑酯／N-乙烯基咔唑共聚物。分别用IR、UV—vis对其结构进行了表征。利用凝胶渗透色谱仪测定了共聚物的相对分子质量,并讨论了影响相对分子质量的因素,提高引发剂浓度、反应温度都使相对分子质量下降,而延长反应时间则有利于增加相对分子质量。     

改性骨架镍催化加氢合成3-氨基-9-乙基咔唑研究

以改性骨架镍为催化剂，对3-硝基-9-乙基咔唑进行低压液相催化加氢合成3-氨基-9-乙基咔唑。研究了催化剂／溶剂体系、温度和氢气压力等因素对加氢反应的影响，并进行了催化剂的循环套用试验和放大试验。     

国内简讯

国内简讯用混合相转移催化剂制取Ｎ┐乙基咔唑新工艺Ｎ－乙基咔唑可作染料中间体、农用化学品和化学试剂，在染料工业中主要用于生产永固紫ＲＬ。Ｎ－乙基咔唑的传统生产方法有：①以硫酸二乙酯为烷基化剂、以丙酮为溶剂在碱性条件下进行烷基化反应，该法丙酮耗量大，不易...     

提高颜料永固紫粗品合成收率的一种方法

颜料永固紫粗品的合成以咔唑为起始原料,在相转移催化剂的存在下与溴乙烷反应得到N-乙基咔唑,收率96％以上。N-乙基咔唑在氯苯中与稀硝酸反应得到N-乙基-3-硝基咔唑,收率70％左右。N-乙基-3-硝基咔唑经催化加氢还原后生成N-乙基-3-氨基咔唑,收率接近理论量,它与四氯苯醌经缩合、闭环反应生成永固紫粗品,两步反应的收率在92％以上。很明显,在合成永固紫粗品的整个过程中,提高粗品收率的关键在于改进N-乙基咔唑的硝化反应及其后序操作。     

阴离子相转移催化重氮偶合反应的研究

研究了十二烷基苯磺酸钠、十二烷基硫酸钠和十二烷基磺酸钠3种阴离子表面活性剂作为阴离子相转移催化剂时在重氮偶合反应中的催化性能。以咔唑和二苯胺为偶合组分合成了6种新的偶氮化合物。     

Photoinduced orientation and cooperative motion of three epoxy-based azo polymers

In this work, photoinduced orientation of three epoxy-based polymers bearing different type azo chromophores was studied. The epoxy-based azo polymers were synthesized through post-polymerization azo-coupling reactions based on an epoxy-based precursor polymer (BP-AN), which was synthesized by the step polymerization between bisphenol-A diglycidyl ether and aniline. The chromophore orientation and cooperative motion of the main-chain groups were studied by birefringence characterization, polarized infrared spectroscopy, and two-dimensional (2D)-IR correlation spectroscopy (COS). The results show that the orientation behavior of the epoxy-based azo polymers is closely related with the electron-withdrawing groups on the azo chromophores. The azo polymer BP-AZ-CN, which contains azo chromophores with cyano as the electron-withdrawing group, shows the fastest birefringence growth rate. The azo polymer BP-AZ-CA, containing carboxyl as the electron-withdrawing group, possesses high birefringence residual value and the highest saturated orientation degree in the series. Cooperative motion between azobenzene moieties and non-photochromic polymer backbone was revealed by polarized FTIR and 2D-IR COS. The photoinduced anisotropy is a result of the orientation of both azo chromophore and polymer main-chain. The understanding of the structure–property relationships can be used to develop materials with better performance for data storage and other applications.     

三种偶氮化合物的合成及三阶非线性光学性能

文章选取具有非线性光学活性的偶氮化合物作为研究对象,合成了一组含不同取代基和不同推-拉电子结构的偶氮化合物,并通过红外光谱、紫外-可见吸收光谱、元素分析、核磁共振氢谱等方法对所合成的偶氮化合物结构进行了表征;用单光束Z-扫描的方法对所合成的偶氮化合物的三阶非线性光学性能进行了测试,并结合理论计算分析研究了分子结构对偶氮化合物三阶非线性光学性能的影响。     

Polymerization of an epoxy resin modified with azobenzene groups monitored by near‐infrared spectroscopy

New photosensitive materials containing photochromic azobenzene moieties were synthesized. For this purpose, an epoxy resin based on diglycidyl ether of bisphenol A (DGEBA) was reacted with an azobenzene chromophore (disperse orange 3, AZ) to satisfactorily synthesize an azo‐modified prepolymer, which was then used to generate series of epoxy‐based polymers containing azo groups. Three different amines were used as hardeners, with the aim of obtaining materials with different chemical structures. Understanding the epoxy resin polymerization kinetics is essential for intelligent processing of materials. Near‐IR (NIR) spectral analysis was used to follow the polymerization kinetics. The quality of the NIR spectra enables concentrations of individual chemical species to be measured in real time. Conversion of epoxy and primary amine groups, as well as the concentration of different groups, as a function of reaction time was therefore calculated by this spectroscopic technique. Samples containing azo units were compared to the pure DGEBA/amine systems. Results showed that the azo‐prepolymer incorporation has an accelerating effect on polymerization rate. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Engineering of alpha1-antitrypsin variants selective for subtilisin-like proprotein convertases PACE4 and PC6: importance of the P2' residue in stable complex formation of the serpin with proprotein convertase

Furin and PACE4, members of the subtilisin-like proprotein convertase (SPC) family, have been implicated in the metastatic progression of certain tumors in addition to the activation of viral coat proteins and bacterial toxins, indicating that these enzymes are potential targets for therapeutic agents. Alpha1-Antitrypsin Portland is an engineered alpha1-antitrypsin designed as a furin-specific inhibitor and has been used as a tool in the functional analysis of furin. In this work, we engineered rat alpha1-antitrypsin to create a PACE4-specific inhibitor. Substituting Arg-Arg-Arg-Arg for Ala-Val-Pro-Met(352) at P4-P1 and Ala for Leu(354) at P2' created a potent PACE4- and PC6-specific inhibitor. This variant (RRRRSA) formed an SDS- and heat-stable serpin/proteinase complex with PACE4 or PC6 and inhibited both enzyme activities. The RRRRSA variant was efficiently cleaved by furin without formation of the stable complex. This is the first report of a highly selective protein-based inhibitor of PACE4 and PC6. This inhibitor will be useful in delineating the roles of PACE4 and PC6 localized in the extracellular matrix.     

N-乙酰-L-酪氨酸甲酯偶氮衍生物的合成及紫外可见光谱学性质

以N-乙酰-L-酪氨酸甲酯为原料,合成了6个新型的偶氮衍生物,通过IR、~1HNMR、~(13)CNMR、EI-MS和元素分析进行了表征。考察了所合成化合物的偶氮式-腙式互变异构以及溶剂和pH对紫外可见光谱的影响。结果表明,溶质-溶剂相互作用会影响化合物在不同溶剂中的λ_(max)发生微小的变化,分子内和分子间氢键的作用影响较大。溶液pH会直接影响偶氮式和腙式的平衡构成,随着pH的增加,偶氮式在偶氮式-腙式互变异构平衡中的比例逐渐降低。这些偶氮化合物有望成为一类潜在的pH指示剂。     

蜡状芽孢杆菌JL好氧脱色偶氮染料的特性研究

研究了蜡状芽孢杆菌JL在好氧条件下对偶氮染料脱色的特性。试验结果表明,菌株JL在好氧条件下使偶氮染料酸性大红3R脱色的最适条件为:外加碳源为葡萄糖和酵母膏,其中葡萄糖质量浓度为2.5 g/L,酵母膏质量浓度为1 g/L,pH介于3～7,温度在30～35℃。在最适条件下,菌株JL能够使6种不同结构的偶氮染料脱色。并且脱色产物成分分析表明偶氮染料能够被还原为芳香胺。研究表明菌株JL在偶氮染料废水处理中具有潜在的应用前景。     

Aqueous polymerization of methyl methacrylate initiated by redox pair: Ce(IV)–Azo compounds with methylol functional groups and synthesis of copolymers

Hydroxyl functional azo compounds have been used as reducing agents in redox polymerization of methyl methacrylate (MMA) in conjuction with ceric ammonium nitrate (which acts as an oxidizing agent in aqueous nitric acid at 20°C). Kinetic measurements were followed by gravimetric method, at lower conversions, not exceeding 10% conversion. The dependence of rate of polymerization and average molecular weight, which was determined by gel permeation chromatography (GPC), on azo, Ce(IV), and MMA concentrations, respectively, were investigated. The homopolymers, which contain thermo-and photolabile azo groups, were utilized with different comonomers to give block or graft copolymers depending on termination mechanism of homopolymerization. © 1994 John Wiley & Sons, Inc.     

Controlling mobility and birefringence of azo chromophores in epoxy polymers

Polymers containing azobenzene units are of special interest due to the reversibility of their photo‐orientation. Applications of these materials are in the fields of optical information storage, information processing, optical switching devices and others. In the work reported, we synthesized, characterized and compared the optical behaviour of azo‐modified epoxy polymers. With this goal in mind, Disperse Red 13 was selected as azo chromophore and two different amines, N,N‐benzyldimethylamine and 4‐(dimethylamine)pyridine, as initiators of the epoxy homopolymerization. The influence of the degree of union between azo chromophore and matrix in crosslinked polymers, and, in consequence, the azo mobility, on the optical behaviour (birefringence and dichroism) of resulting films was evaluated. An analysis of the dynamics of the writing and relaxation processes was also carried out. When the azo chromophore was covalently linked to the network, the maximum birefringence was reached three times faster. Also, two completely different optical behaviours were observed taking into account the occurrence or not of covalent bonding between the chromophore and the matrix. A remnant birefringence of around 60% was retained in the first case; an on‐off optical behaviour was observed in the second case. Copyright © 2011 Society of Chemical Industry     

论偶氮染料的偶氮-腙互变异构

偶氮染料存在着偶氮-腙互变异构。其中包括两个概念, 一是偶氮体和腙体是一对异构体, 由其结构不同导致其发色和化学性能不同;二是两种异构体在满足某种条件下可以互变。对偶氮体或腙体结构的识别是研究偶氮染料结构与性能的基础。当前染料学术界和产业界对偶氮-腙互变异构有两大误识:偶氮体即腙体, 两者不必加以区分;以及两者既为互变异构, 则时刻处于变化中而无法进行区分。本文针对上述误识, 讨论了两种异构体的结构与性能关系。一个偶氮染料的偶氮体及醌腙体是两种结构与性能, 如紫外-可见光谱吸收、化学反应性能及牢度不同的化合物。通常仅以某种异构体结构为稳定状态存在, 折中结构结决定了它的颜色和染色性能。两者仅在某种特定的条件下可以互相变化。这些条件取决于化合物结构、所处环境条件, 如温度、溶剂、介质pH等环境因素对偶氮-腙平衡的影响。介绍了用其红外光谱、拉曼光谱、核磁波谱、质谱以及晶体的X衍射谱来确认互变异构体的方法。