首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
《合成通讯》2013,43(11):1691-1695
Using potassium chlorate, sulfuric acid and ferrous sulfate as a catalytic oxidation system to oxidize the aryl substituted carbazide to prepare new type bisazo compounds in one phase have been described for the first time in this paper. Eight bisaryl carbodiazones have been synthesized in high yields under mild conditions. A possible mechanism has been suggested.  相似文献   

2.
偶氮类化合物在人们的日常生活和现代科技方面具有重要的应用价值,可被广泛地用作染料 ,分析试剂,非线性光学材料,激光盘信息存贮材料和现代彩色照相技术中的油溶性染料[1].  相似文献   

3.
采用不同尺寸的聚四氟乙烯(PTFE)微管为内外管、玻璃毛细管(glass capillary)或聚丙烯(PP)中空纤维为内管管头设计制作了一种共轴微通道反应器(N-CAMFR).以聚乳酸(PLA)/二氯甲烷(CH2Cl2)溶液和海藻酸钠(Na-alginate)水溶液分别作为分散相,在N-CAMFR内形成O/W和W/O乳液后,收集乳液并使其中的液滴固化,制备出单分散的生物质聚合物微珠(BPM).研究了固定管头尺寸时,改变连续相的流速及表面活性剂的种类对微珠尺寸的影响.结果表明,使用N-CAMFR制备微珠,反应过程流畅,所制得的微珠粒径分布均匀,其分散系数(f)可低至2.16%;通过改变内管管头的尺寸可方便地调控N-CAMFR的尺度,与传统微通道反应器相比,降低制作成本的同时拓宽了其应用的范围,而且降低了微通道反应器堵塞的几率.为粒径范围200~800μm的单分散聚合物微珠的可控连续制备提供了快捷绿色的新方法.  相似文献   

4.
A surfactant-assisted method for preparing colloidal spheres with narrow size distribution from a polydispersed azo polymer has been developed in this work. The colloidal spheres were formed through gradual hydrophobic aggregation of the polymeric chains in THF-H2O dispersion media, which was induced by a steady increase in the water content. Results showed that the addition of a small amount of surfactant (SDBS) could significantly narrow the size distribution of the colloidal spheres. The size distribution of the colloidal spheres was determined by the concentrations of azo polymer and the amount of surfactant in the systems. When the concentrations of polymer and surfactant amount were in a proper range, colloidal spheres with narrow size distribution could be obtained. The colloidal spheres formed by this method could be elongated along the polarization direction of the laser beams to be a new type of the colloid-based functional materials. upon Ar^+ laser irradiation. The colloidal spheres are considered  相似文献   

5.
Abstract— A simple procedure for the isolation and purification of 124 kDa phytochrome (phyA) from etiolated Avena seedlings has been developed employing ammonium sulfate back-extraction. After solubilization of the ammonium sulfate precipitate (250 g/L) an additional ammonium sulfate fractionation with 17 g per 100 mL rather than column chromatography was performed. After several steps of the "washing-out" procedure with 100 mM phosphate buffer, phytochrome was solubilized in 10 m M phosphate buffer. The resulting phytochrome had a specific absorbance ratio (SAR = A666/A28o) ranging from 0.60 to 0.85. These values are equivalent to those of phytochrome preparations after hydroxyla-patite chromatography-ammonium sulfate back-extraction. The total isolation-purification time was 8 h and yield of the chromoprotein was 50% higher than the yield using conventional techniques. The phytochrome preparation, after application to a Toyopearl HW-65S gel filtration column, produced very pure 124 kDa phyA with a specific absorbance ratio greater than 1.00. The spectral characteristics are identical to those described for the best of the highly purified native chromoprotein preparations.  相似文献   

6.
<正> 聚合物的折射率n是表征其光学性质的基本参数之一。块状透明聚合物的折射率通常是用Abbe折射仪测定的。薄膜样品折射率的测定较为困难,一般也是通过全内反射临界角的测量来得到的,精度一般为10~(-3)。用这种方法不易测定双折射及折射率随温度等的微小变化,给一些研究带来了较大的误差。 另一方面,聚合物的折射率与克分子极化强度R的关系由Lorentz-Lorenz方程  相似文献   

7.
《合成通讯》2013,43(13):1993-1999
Reaction of dichloroketone 2 with NEt3 gave indenone (4) in high yield. Catodic reaction of 2 in the presence of C/Pt electrodes afforded the rearranged product 3 in high yield besides a small amount of chlorohydroxyketone 5. Reaction of rearranged dichloroketone 3 with NEt3 provided indenone (4) as the sole product. The mechanism of these reaction was discussed.  相似文献   

8.
一种制备MCM-41/Y分子筛复合材料的新方法   总被引:11,自引:2,他引:11  
以Y沸石为内核,以异丙醇铝为铝源,正硅酸乙酯为硅源,十六烷基三甲基溴化铵为模板剂,在控制条件下合成了MCM-41/Y分子筛复合材料,用X射线衍射,扫描电镜,低温N2吸附等手段对其物理化学性能进行了表征,用萘的液相叔丁基化反应考察了这种新材料的催化性能,结果表明,这种复合材料与HY相比,对反应的活性虽有所下降,但选择性却大大提高。  相似文献   

9.
《合成通讯》2013,43(16):2543-2547
An alternative and convenient procedure for transformation of peroxides to hydroxy ketones by potassium carbonate is described.  相似文献   

10.
一种合成方钠石的新方法   总被引:2,自引:0,他引:2  
一种合成方钠石的新方法冯芳霞窦涛萧墉壮(太原工业大学精细化工研究所,太原030024)钟炳(中国科学院山西煤炭化学研究所,太原030001)关键词方钠石,正丁胺,模板剂,非水体系方钠石不仅是一种光致变材料[1,2],而且是首先进入无机功能材料领域的...  相似文献   

11.
以自制杂化双向拉伸聚丙烯/氧化硅(BOPP/SiOx)有机/无机杂化膜为基材,由喷墨打印机直接在杂化膜表面打印色阶图案,制备出对紫外光强度呈梯度透过的梯度光掩模;通过此掩模控制,在双向拉伸聚丙烯(BOPP)和聚对苯二甲酸乙二醇酯(PET)表面实施受限光催化氧化(CPO)光感应羟基化反应、受限光接枝丙烯酸(AA)以及表面...  相似文献   

12.
《合成通讯》2013,43(21):3383-3393
Oxidation of alcohols to carbonyl compounds has been carried out by utilization of Jones reagent supported on silica gel (SJR). The SJR procedure has advantages over traditional Jones oxidation procedure. This procedure is safer to carry out and simplified workup by allowing organic media.  相似文献   

13.
Abstract— Highly purified Chi a and b were prepared from spinach leaves in a short time by a combined use of the column chromatography with DEAE-Sepharose CL-6B and Sepharose CL-6B. The former chromatography eliminated carotenoids, phaeophytin and chlorophyllide, and the latter chromatography efficiently separated Chi a and b .  相似文献   

14.
α-芳基和α-烯基羰基结构是一类天然生物分子的重要特征结构.我们曾用二烷基烯烃基铝同α-卤代酸酯反应立体选择性地合成β,γ-不饱和酸酯.本文通过二烷基烯烃基铝与丁基锂形成的酸根型配合物,与α-卤代酰胺反应制备β,γ-不饱和酰胺.  相似文献   

15.
一种制备勃姆石溶胶的新方法   总被引:1,自引:0,他引:1  
以氯化铝为起始原料经离子交换过程制备勃姆石溶胶.该方法将阴离子交换树脂加入三氯化铝溶液中,提供OH-离子的同时可同步去除等量Cl-离子.应用TEM对溶胶胶粒结构进行了研究,采用XRD、FTIR对不同条件下制备的凝胶结构进行了分析,对制备勃姆石溶胶过程中的影响因素进行了探讨.结果表明,老化时间和溶液中Cl-离子浓度对产物的结构和性能有显着影响,Cl一离子完全去除后经老化可以获得稳定的勃姆石溶胶.等温氮气吸附结果显示,r氧化铝的比表面积随着老化时间的延长而下降.老化4h和16h后得到γ-氧化铝的比表面积分别为223.12m2/g和176.86m2/g.  相似文献   

16.
诺氟沙星(Norfloxacinium)是近几年合成的新抗菌素(图1)。具有抗菌谱广,疗效好,毒性低等优点。目前已广泛应用于临床。中国药典1990年版中对诺氟沙星胶囊的含量测定采用非水滴定法。本文改进了此法,采用紫外分光光度法测定该品种含量。实验表明该法简便、快速、重现性也较好。仪器与试药仪器:日本岛津UV-2100紫外分光光度计;日本岛津UV—260紫外分光光度计;751—GW(上海分析仪器厂)。  相似文献   

17.
A new method for the direct conversion of various oximes into aldehydes and ketones by treatment with N-bromosaccharin is described. N-bromosaccharin can be used for an effective, selective and mild oxidizing agent for the regeneration of carbonyl compounds from oximes in good yield.  相似文献   

18.
Reduction of 1-t-butyl-1,2,3,4,5-pentaphenylstannole by lithium gave the stannole dianion. Reduction of the bi(1,1-stannole) having a t-butyl group on the tin by lithium also gave the stannole dianion, the formation of which was evidenced by spectral analysis and chemical trapping reaction.  相似文献   

19.
卤化银乳剂经晶体生长、水洗、化学增感以后,还必须进行光谱增感,即加入感绿和感红的染料,以扩大卤化银乳剂微晶体对绿光和红光的光谱响应范围.  相似文献   

20.
我们在工作中发现亚硫酸钾水溶液与1的正常反应产物是2[1],但加二氧六环于上述反应体系后发生了一个不同的反应,得到另一个产物3,即:3是熔点286℃的无色结晶,IR:1010cm-1;19FNMR:δCFCl3为82.0,133.4ppm,这两个核磁共振吸收峰均为单峰并强度相等。元素分析与氧化还原滴定也符合3的结构。这一反应条件温和,产率及选择率都高达90%。因为这种反应未见文献报道,我们建议称之为“脱碘亚磺化反应”,它具有自由基反应的性质。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号