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1.
以五甲基二乙烯三胺(PMDETA)、脂肪醇聚氧乙烯醚(FAPOE)和环氧氯丙烷(ECP)为原料,分两步合成了一种含聚氧乙烯醚链三头季铵盐的表面活性剂。对反应影响因素、产物结构与部分性能进行了分析与表征。结果表明:第一步反应n(ECP):n(FAPOE)为2.5~3:1,溶剂为正己烷,四丁基溴化铵作相转移催化剂,无水K2CO3作缚酸剂,时间6~8h。第二步反应n(中间体):n(PMDETA)为3.5—4.0:1,溶剂为正丁醇,时间40-45h;溶剂与时间是主要影响因素。定性表征符合产物结构:定量表征n(Cl^-):n(阳离子部分)为3.4:1,略高于理论值。产物的表面活性高,1.0×10^-4mol/L水溶液的表面张力可降至6.65mN/m。  相似文献   

2.
纳米氧化铜催化化学发光性能及其氨基酸检测   总被引:7,自引:0,他引:7  
用低热固相配位化学反应制得纳米氧化铜并对其进行了透射电镜和X射线衍射表征,得到的纳米氧化铜平均粒径为10nm。用制得的纳米氧化铜催化精氨酸和天冬氨酸的鲁米诺化学发光体系,催化性能较分析纯氧化铜和硫酸铜溶液分别提高了5.65和4.51倍。氨基酸的检出限达10^-9mol/L。  相似文献   

3.
以硼氢化钾和甲醛为还原剂,采用双还原剂还原法制备了铜粒子。探讨了双还原剂还原法的机理以及影响纳米铜粒子生成的主要因素,利用XRD、TEM和激光颗粒测量仪对反应产物进行了表征。结果显示,反应产物为单质铜粒子,形貌呈球形,粒径主要分布在15-40nm;SDS和PVP的配合使用可有效防止纳米铜粒子团聚。  相似文献   

4.
王健  吴昊  黄承志 《中国科学B辑》2008,38(10):929-937
应用等离子共振吸收光谱和扫描电子显微镜,观察了碘和盐酸四环素反应引起的金纳米棒形态的变化.实验表明,单质碘能对金纳米棒产生融合作用,引起金纳米棒径向比的减小和纵向吸收波长的蓝移;但当盐酸四环素存在时,单质碘与盐酸四环素作用,减低了碘的有效浓度,减弱了碘对金纳米棒的融合作用,使金纳米棒的纵向吸收峰随盐酸四环素浓度的增大发生线性红移.据此本文建立了一种测定盐酸四环素的方法.方法的线性范围为5.0×10^-5mol/L~5.0×10^-4mol/L,检测限为2.4×10^-6mol/L(3σ/k).常见物质不干扰测定.方法成功应用于合成样中四环素测定,回收率在92.8%~107.2%之间,RSD值小于4-3%.用标准加入法测定了3个乳制品厂生产的牛奶中盐酸四环素,表明牛奶中的四环素残余物浓度较低,符合安全标准.  相似文献   

5.
利用甲醛与硫酸铜还原反应,通过添加铜晶核,控制反应液的pH、温度等条件,在酚醛树脂合成体系内原位生成了球形、粒度分布30~50nm的纳米铜粒子。采用红外光谱分析、热重分析和冲击试验对纳米铜改性酚醛树脂的结构和性能进行了表征,结果表明,(1)纳米铜与酚醛树脂间存在着化学作用;(2)纳米铜对酚醛树脂的耐热性有显著影响,与纯酚醛树脂的相比,纳米铜改性酚醛树脂的初始分解温度可提高51℃;(3)纳米铜对酚醛树脂的韧性有显著影响,与纯酚醛树脂的相比,纳米铜改性酚醛树脂的冲击强度可提高约52%。  相似文献   

6.
研究了影响Fe(OH)3进行酸式电离反应的因素,在多种浓度和温度条件下的NaOH浓溶液中采用SnO2-Sb2O3/Ti电极,研究FeO4^2-/FeO2^-体系的电化学氧化还原反应参数及其变化趋势,结果证实该体系发生电化学氧化还原反应的最佳碱溶液浓度范围为12—14mol/L,最佳温度范围为295~315K.阐明了在实验条件下FeO4^2-/FeO2^-氧化还原体系中存在由FeO4^2-/FeO2^-构成的氧化还原电对,而FeO2不直接与FeO2构成氧化还原电对;并给出了FeO4^2-/FeO2^-氧化还原体系的Latimer图.  相似文献   

7.
新闻     
《分析化学》2008,36(11)
来自同济大学化学系的田阳研究小组报道了基于盘状纳米氧化锌(ZnO)的铜锌超氧岐化酶(Cu,ZnSOD)的直接电子传递,在此基础上构筑的新型超氧离子(O2^-)传感器及其在豆芽体内O2^-检测中的应用(Anal.Chem.,80(15),5839—5846,2008)。研究人员通过一步电沉积的方法制备了盘状纳米ZnO,并实现了Cu、Zn-SOD的直接电子传递,其异相电子传递速率常数是(17±2)s^-1。  相似文献   

8.
锌跟硫酸铜溶液反应.在锌粒表面生成一层黑色粉状物。通过实验证实,黑色粉状物是铜、氧化铜和锌粉的混合物。氧化铜的生成.是硫酸铜水解生成氢氧化铜,氢氧化铜分解生成氧化铜。锌跟硫酸铜溶液反应,要观察到紫红色铜的生成,就要抑制水解,把硫酸铜配成饱和溶液。  相似文献   

9.
砷锑铋对阴极铜沉积过程的影响   总被引:6,自引:0,他引:6  
用线性电位扫描、XPS、XRD等方法,研究了砷锑铋离子对酸性硫酸铜系统中铜沉积反应动力学及铜沉积层成份与结构的影响.研究表明:As(Ⅴ)离子能增大铜沉积反应的交换电流密度,对铜沉积过程起去极化作用;Sb(Ⅲ)、Bi(Ⅲ)离子均使铜沉积反应交换电流密度减小,对铜沉积过程起极化作用;但砷锑铋离子不改变铜沉积反应的机理.测试表明:用200A/m2电流密度电解,砷锑铋不会在阴极沉积,也不影响铜沉积层的晶面择优取向(220);用1500A/m2电流密度电解,发现砷与铋在阴极与铜共沉积,铜沉积层的晶面择优取向变为(111),沉积层中铜主要以金属Cu和少量Cu2O形式存在,铋主要以Bi2O3形式存在.  相似文献   

10.
硅基分子印迹技术制备铜离子选择电极   总被引:1,自引:0,他引:1  
以3-(2-氧基乙基氨基)丽基三甲氧基硅烷作为功能分子,铜离子为模板,将分子印迹技术与溶胶凝胶技术相结合,制备了铜离子选择电极,探讨了电极的响应机理.该电极对铜离子有较好的能斯特响应特性,其线性响应范围为5.00×10^-2~3.98×10^-6mol·L^-1,斜率为31.5mV/pC(-logc),检出限为1.00×10^-6mol·L^-1.同时该电极显示了较好的选择性,重现性和稳定性.  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

13.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

14.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

15.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

16.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

17.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

18.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

19.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

20.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

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