锌-硫氰酸铵还原体系用于氢化偶氮苯的合成

氢化偶氮苯是重要的精细有机化工原料及中间体,染料工业用于制备联苯胺染料,医药工业用于生产解热镇痛药保泰松等[1]。传统的制备方法是在强碱性介质中用锌粉还原硝基苯,反应时间长,产率低[2]。用硫化铵快速还原偶氮苯生成氢化偶氮苯[3],则硫化铵用量大,刺激性气味对操作者及环境造成极大危害。我们采用ＮＨ4ＣＮＳ的饱和溶液与锌粉组成还原体系,在25℃时还原偶氮苯,反应条件温和,锌粉用量少,时间短,产率高,操作简单。反应方程式如下:ＰｈＮ=ＮｐＨ(橙红色)Ｚｎ-ＮＨ4ＣＮＳ25℃,ＥｔＯＨＰｈＮＨＮＨＰｈ(白色)1　实验部分在50ｍｌ圆底…     

新型偶氮苯金属配合物的合成与性能

合成了新型偶氮苯金属配合物。分别采用光谱分析、热分析及X射线衍射测试技术对产物进行了表征和测试。结果表明,连接偶氮苯和金属配合物之间碳链的长度对该化合物的相转变和荧光特性具有特殊的影响。该系列化合物在紫外光和热作用下具有99%以上的偶氮苯顺-反异构化反应效率;具有290和560 nm这2个波段的荧光发射光谱。由其中1个金属配合物分散在聚甲基丙烯酸甲酯网络而形成的介质可作为全息信息存储材料而实现全息图像的写入和读出。     

偶氮苯和氧化偶氮苯液晶基元侧链聚硅氧烷液晶的合成和性能研究

利用侧链带酰氯基的聚硅氧烷与取代偶氮苯酚进行大分子反应,合成了6种以偶氮苯氧羰基为侧链的聚硅氧烷Ⅲ_a-f;将其中的Ⅲ_a-c进行氧化,得到3种以氧化偶氮苯氧羰基为侧链的聚硅氧烷Ⅳ_a-c聚合物结构通过核磁共振、红外光谱和元素分析表征,利用偏光显微镜和差热分析仪研究了聚合物的相行为.讨论了苯环上取代基和液晶基元的中心桥键对聚合物液晶性能的影响.     

3,3''''-二溴氧化偶氮苯的绿色合成及晶体结构

在β-环糊精、氢氧化钠的水介质中,由间溴硝基苯直接合成3,3'-二溴氧化偶氮苯(1),其结构经1H NMR表征.采用X-射线单晶衍射仪测定了1的晶体结构,属单斜晶系,P2(1)空间群,晶胞参数为:a=0.79596(11)nm,b=0.58620(8)nm,c=2.5968(4)nm,α=90°,β=95.781(2)°,γ=90°,V=1.2055(3)nm3,Z=4,F(000)=688,Mr=356.02,Dc=1.962 g·cm-3,μ=6.708 mm-1,R1=0.0311,wR2=0.0766.     

3,3′-二溴氧化偶氮苯的绿色合成及晶体结构

在β-环糊精、氢氧化钠的水介质中,由间溴硝基苯直接合成3,3′-二溴氧化偶氮苯(1),其结构经1H NMR表征。采用X-射线单晶衍射仪测定了1的晶体结构,属单斜晶系,P2(1)空间群,晶胞参数为:a=0.79596(11)nm,b=0.58620(8)nm,c=2.5968(4)nm,α=90°,β=95.781(2)°,γ=90°,V=1.2055(3)nm3,Z=4,F(000)=688,M r=356.02,Dc=1.962 g.cm-3,μ=6.708 mm-1,R1=0.0311,wR2=0.0766。     

对称偶氮苯的合成及性质

以Cu(Ⅰ)催化的氨基偶联反应为关键步骤,合成了末端各带3条柔性烷基链的最简单小分子偶氮凝胶剂——对称偶氮苯化合物A;通过~1H NMR,~(13)C NMR和元素分析鉴定了其结构;采用紫外光谱和SEM等手段对其性质进行了表征.凝胶实验结果表明,该化合物能在极性、非极性有机溶剂中形成凝胶,且该凝胶在紫外光和可见光照射下能够发生凝胶-溶液的可逆转化.SEM表征结果表明,该凝胶具有由纤维束聚集成的三维网状结构,此外还具有热响应性和机械响应性.紫外光谱测试结果表明,该化合物具有光响应性.     

含咔唑和偶氮苯的乙炔衍生物的合成

采用Sonagashira偶联反应和N-烷基化反应合成了含有咔唑和偶氮苯的乙炔衍生物:3-乙炔基-9-(4-[4-(硝基)苯基偶氮苯]氧)亚丁基咔唑3.其结构通过IR,1H NMR,13C NMR,元素分析和X-射线单晶衍射法测定.标题化合物属单斜晶系,P21/c空间群;a=9.238(3),b=28.240(8),c...     

锌-丙酸铵还原体系用于氢化偶氮苯的合成

选用锌粉和镁粉与不同饱和铵盐（草酸铵、丙酸铵和苯甲酸铵）水溶液组成还原体系,由偶氮苯制备氢化偶氮苯,根据反应时间及结果选取锌一饱和丙酸铵水溶液为最佳还原体系。在反应温度25℃时,研究了锌一饱和丙酸铵水溶液还原体系还原偶氮苯反应,考察了偶氮苯与锌粉物质的量比、饱和丙酸铵水溶液的用量对氢化偶氮苯收率的影响。实验结果表明：偶...     

全偶氮苯官能化树枝状聚合物的合成

以4-羧基-4'-(1, 2-丙二醇醚)-偶氮苯为AB2单体, 由4-羧基-4'-正丁基醚-偶氮苯出发, 采用收敛法合成了以偶氮苯为结构单元的新型树枝状聚合物, NMR, GPC和 MALDI-TOF-MS的测试结果表明, 合成的树枝状分子具有规整的分子结构和单分散的分子量分布.     

Macrometallocycle binuclear NHC silver(I) complex with bridging azobenzene: Synthesis,structure and recognition for hydrogen sulfate

One bis-imidazolium salt 2,2′-di[2’’-(N-methyl-imidazoliumyl)ethoxyl]azobenzene hexafluorophosphate (LH₂·(PF₆)₂) and its macrometallocycle binuclear N-heterocyclic carbene silver(I) complex [(LAg)₂](PF₆)₂ were prepared and characterized. The structure of [(LAg)₂](PF₆)₂ was determined by X-ray single crystal diffraction, ¹H NMR and ¹³C NMR spectroscopy. In complex [(LAg)₂](PF₆)₂, one 34-membered macrometallocycle was formed by two biscarbene ligand L and two silver(I) ions. Additionally, the selective recognition of hydrogen sulfate using [(LAg)₂](PF₆)₂ as a chemosensor was investigated on the basis of fluorescence titrations, ultraviolet titrations, ¹H NMR titrations, HRMS and IR spectra. Complex [(LAg)₂](PF₆)₂ was demonstrated to be an effective chemosensor for hydrogen sulfate.     

Synthesis of cyclic azobenzene analogues

Reaction of 2,2′-dinitrodibenzyl with lead metal powder in the presence of a basic triethylammonium formate buffer gave a cyclic azoxybenzene, 11,12-dihydrodibenzo[c,g][1,2]diazocine-5-oxide. The latter compound was converted into cyclic azobenzene and analogues (chloro-, bromo-, and cyano-) through subsequent transformations. Hydrolysis of the cyano cyclic azobenzene gave the corresponding carboxylic acid. This carboxylic acid was finally reacted with d-threoninol to give the corresponding amide, which readily undergoes photoisomerization upon illumination with light.     

Synthesis,structure, and properties of bifunctional azobenzene monomers and polymers on their basis

A new preparative procedure for the synthesis of new bifunctional azo monomers with different ratios of methacryloyl and hydroxyl groups has been developed. The monomers thus prepared contain a nonlinear optical 4′-amino-4-nitroazobenzene group and can be involved in polymerization, polycondensation, and polymer-analogous transformation reactions to afford linear and network polymers. The free-radical copolymerization of 4′-[N-methyl-N-(3-methacryloyloxy-2-hydroxypropyl)]amino-4-nitroazobenzene with methyl methacrylate has been studied with the aim of preparing azobenzene [1+0] prepolymers with pendant chromophore groups, and the reactivity ratios and reactivity factors of the comonomers have been calculated. The hydroxyl-containing copolymers are characterized by rather high molecular mass, satisfactory heat resistance and thermal stability, and good film-forming behavior. These copolymers may be crosslinked with the use of diisocyanates and thus may form thin optically homogeneous red films.     

活性镁及活性氢化镁的合成

研究了在真空下90-150℃间使蒽镁分解生成高活性镁. 再常压加氢, 制得氢化镁的方法. 这一过程中, 镁的活化可循环使用蒽, 基本上不消耗任何试剂, 在分解前用过渡金属化合物掺杂到蒽镁中去可改善活化镁的氢化行为. 当蒽镁中掺杂5%的Cp2TiCl2时, 吸氢温度可降至90℃.     

Synthesis and mesomorphic properties of fluoro-containing azobenzene liquid crystals

Four series of azobenzene liquid crystal compounds containing a fluorinated tolan unit have been synthesized. The mesomorphic behaviours of these compounds were characterized by differential scanning calorimetry and optical polarizing microscopy. The compounds of these series exhibit a nematic, a smectic C or a smectic B phase. This investigation revealed that the alkoxy chain at the side of the azobenzene moiety plays a more important role in the formation of smectic phases than the one at the side of the tolan moiety.     

Synthesis and photoresponsive study of azobenzene centered polyamidoamine dendrimers

A new series of novel polyamidoamine (PAMAM) dendrimers 4, 5 and 6 possessing azobenzene units specifically at the core were prepared and their reversible trans/cis photoisomerization properties were studied. PAMAM dendritic wedges as well as azo-based PAMAM dendrimers were fully characterized by means of FT-IR, NMR (¹H and ¹³C), mass spectrometry (MALDI-MS), thermogravimetric and elemental analysis.     

Synthesis of photochromic maleimides containing dithienylethene and azobenzene fragments

Russian Journal of Organic Chemistry - Maleimides containing dithienylethene and azobenzene fragments have been synthesized by reaction of dithienyl-substituted maleic anhydrides with...