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1.
Ferrocenyl-chalcones and their bichalcone analogues were characterized by IR and NMR spectroscopy, as well as electrochemically. Their UV–visible spectra were recorded, and the electronic transitions were assigned by time-dependent DFT calculations. The single-crystal X-ray structures were determined for two ferrocenyl bichalcones.  相似文献   

2.
Three pentahaloanilines were prepared by stepwise halogenation of 3,5-difluoroaniline and were deaminated to form pentahalobenzenes. Alternatively, two pentahalobenzenes were obtained by lithiation followed by iodination of 1,3-difluoro-4,6-dihalobenzenes. Alkylthiolation reactions of pentahaloanilines and benzenes in Me2SO were investigated.  相似文献   

3.
Phosphaquinomethane and phosphathienoquinomethanes sterically protected by Mes* (Mes* = 2,4,6-tri-tert-butylphenyl) were synthesized by 1,6-dehydration of the corresponding 4-phosphinoaryl carbinols. Structural similarities to the conventional quinoid compounds were revealed by 1H, 13C, and 31P NMR study and further confirmed by X-ray crystallography of the phosphathienoquinomethane. The corresponding anion radicals were generated by reduction with sodium, and considerable delocalization of an unpaired electron was demonstrated by EPR.  相似文献   

4.
The effect of initial concentration, temperature, and shaking rate on the adsorption of three dyestuffs [orange II (O-II), crystal violet (CV), and reactive blue 5 (RB5)] and an ideal adsorbate, p-nitrophenol (PNP), by chitosan (Sigma C-3646) and the effect of temperature on the adsorption of O-II and CV by monocarboxymethylated chitosan (MCM-chitosan) were investigated. Kinetic data obtained for the adsorption of each dyestuff and PNP by chitosan and of O-II and CV by MCM-chitosan at different temperatures were applied to the Lagergren equation, and adsorption rate constants (k(ads)) at these temperatures were determined. These rate constants related to the adsorption of O-II and RB5 by chitosan and of O-II by MCM-chitosan were applied to the Arrhenius equation, and activation energies (E(a)) were determined. In addition, the isotherms for adsorption, at different temperatures, of each dyestuff and PNP by chitosan and of O-II and CV by MCM-chitosan were also determined. These isothermal data were applied to linear forms of isotherm equations that they fit, and isotherm constants were calculated. Because the isotherm curves obtained for the adsorption of O-II and CV by chitosan and of CV by MCM-chitosan fit the Langmuir adsorption isotherm, b constants were applied to thermodynamic equations, and thermodynamic parameters (delta G, delta H, and delta S) were calculated. Lastly, chitosan and MCM-chitosan were compared with respect to the ability to take up the dyestuffs and PNP.  相似文献   

5.
以三氯化硼和氯化铵为原料,甲苯为溶剂,高产率(98%)地合成了具有硼和氮的六元环结构的三氯环硼氮烷(1);1分别与正丙胺(Ⅰ)和异丙胺(Ⅱ)反应制得正丙胺基环硼氮烷(1~Ⅰ)和异丙胺基环硼氮烷(1~Ⅱ);1~Ⅰ和1~Ⅱ经过脱胺和热聚合反应制得聚硼氮烷先驱体(2和3).用IR,NMR和XRD等对2和3的组成与结构进行了分析,探讨了聚硼氮烷的胺基取代基对聚硼氮烷聚合反应性及产物结构的影响.研究结果表明,3具有更强的热聚合特性.  相似文献   

6.
Abstract

The synthesis and stereochemistry of tricoordinated optically active selenium and tellurium compounds are described. Telluronium salts, telluronium imides, and seleninic acids were prepared and optically resolved by fractional recrystallization of diastereomeric mixtures or by chromatography using a chiral column of racemic mixtures. Diphenyl dichalcogenides also were optically resolved by chiral crystallization. Their absolute configurations were determined or estimated based on X-ray crystallographic analysis, specific rotations, and circular dichroism spectra. The kinetic studies and the mechanism for the racemization were also studied.  相似文献   

7.
Polyimides of different structures were synthesized by reaction of 1,4-phenylene diisocyanate (PPDI) and 1,5-naphthalene diisocyanate (NDI) with pyromellitic dianhydride (PMDA) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA). Polyamide-imides were also prepared by reaction of PPDI and NDI with trimellitic anhydride. The optimized condition for polymerization reactions were obtained via the study of model compounds. All polymers and model compounds were characterized by conventional methods. Physical properties of polymers, including thermal behavior, thermal stability, solution viscosity, and solubility behavior, were also studied. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2245–2250, 1999  相似文献   

8.
Pd/ZnO和Ag/ZnO复合纳米粒子的制备、表征及光催化活性   总被引:11,自引:0,他引:11  
 用焙烧前驱物碱式碳酸锌的方法制备了ZnO纳米粒子,采用光还原沉积贵金属的方法制备了Pd/ZnO和Ag/ZnO复合纳米粒子,并利用ICP,XRD,TEM和XPS等测试技术对样品进行了表征,初步探讨了贵金属在ZnO纳米粒子表面形成原子簇的原因.以光催化氧化气相正庚烷为模型反应,考察了样品的光催化活性以及贵金属沉积量对催化剂活性的影响.结果表明:沉积适量的贵金属,ZnO纳米粒子光催化剂的活性大幅度提高.同时,深入探讨了表面沉积贵金属的ZnO纳米粒子光催化剂活性有所提高的内在原因.  相似文献   

9.
磺酰脲衍生物;除草活性;含嘧啶环的苯基磺酰脲、吡唑磺酰脲的合成及生物活性  相似文献   

10.
Nicotine and its metabolite, cotinine, were measured in rat plasma and brain by gas chromatography-mass spectrometry. Both agents were extracted from plasma and brain, separated on a capillary column, and quantified by single-ion monitoring. The major fragment ions of nicotine and cotinine at m/z 84 and m/z 98, respectively, were monitored by electron-impact ionization detection and the protonated molecular ions at m/z 163 and m/z 177, respectively, were monitored by chemical ionization detection. Both compounds were quantified using deuterium-labeled nicotine and cotinine, respectively, as internal standards.  相似文献   

11.
High molecular weight copoly(ether ketone)s (PEK) based on 4-(4-hydroxyphenyl)-1-phthalazinone (DHPZ)/4,4′-thiobisphenol (TBP)/4,4′-diflourodiphenylketone (DFK) were prepared by nucleophilic substitution polycondensation. The copolymers were characterized by FT- and ^1H-NMR. Thermal properties and solubility of copolymers were studied.  相似文献   

12.
《Analytical letters》2012,45(10):1079-1087
Abstract

Anodic processes were studied for eugenol, isoeugenol and 2,6-dimethoxy-4-allylphenol by cyclic voltammetry at a glassy carbon electrode in methanol. Preparative electrolyses were also applied coulometrically to these phenols, followed by the separation and the determination of the structures of -e, -2e and -4e products. It was indicated that both radical and cationic reactions were controlled by the applied potentials, the solvent media and the substituents on the aromatic rings.  相似文献   

13.
Ca@C88和Ca@C90的合成、分离和表征   总被引:1,自引:0,他引:1  
利用直流电弧法,合成了含钙的富勒烯金属包合物.通过多步高效液相色谱(HPLC)法,首次分离出含钙的富勒烯金属包合物Ca@C88和Ca@C90 (I,II),用激光解析飞行时间质谱(MAL-DI-TOF MS)和紫外-可见-近红外(UV-Vis-NIR) 光谱进行了表征,并对其分子对称性和电子结构进行了讨论.  相似文献   

14.
用LKB-2277Bioactivity Monitor测定了25℃时间氯、对氯和对氟苯甲酸在水-乙醇混合溶剂中的标准电离焓, 计算了相应体系的标准电离熵。利用Hammett方程对溶剂中酸的取代基常数σ进行了计算, 求取了对应的焓、熵取代基常数σH和σS值及熵反应常数ρS, 利用内部-环境模型和上述常数对溶剂效应和取代基效应进行了解释。  相似文献   

15.
The steroids were derivatised with aroyl chloride to yield the corresponding benzoates. Among them, their 4-methoxybenzoates were obtained in greatest yield and were analyzed by HPLC with the smallest detection limit (10 ng) by means of a UV detector (254 nm). This method of derivatization can be applied for analysis of steroids and triterpenoids from crude products with the HPLC technique.  相似文献   

16.
系列甘露糖醛酸寡糖的制备与鉴定   总被引:1,自引:0,他引:1  
用酸降解法制备了系列甘露糖醛酸寡糖(聚合度2~8),并分析测定了寡糖的结构. 褐藻胶经部分酸水解,于pH=2.85处分级获得聚甘露糖醛酸. 继续用酸降解法降解聚甘露糖醛酸,经凝胶柱层析分离纯化,获得系列甘露糖醛酸寡糖. 用荧光标记糖电泳(FACE)对寡糖进行了分析,并用电喷雾离子化质谱(ESI-MS)、 核磁共振波谱(NMR)及红外光谱(FTIR)进行了结构表征. 本研究用酸降解法制备饱和甘露糖醛酸寡糖,用凝胶柱层析法分离获得系列聚合度的寡糖,为褐藻胶大分子构效关系研究和药物的筛选与发现提供了重要的基础资料.  相似文献   

17.
对烘烤前后南瓜籽中的化学成分进行分析并对比。采用同时蒸馏萃取装置萃取南瓜籽中的挥发性成分,采取超临界CO2萃取技术萃取南瓜籽油脂,并将其分为酸、碱、中性三个部分,用气相色谱-质谱联用方法分析其中化学成分并进行对比。结果表明,南瓜籽挥发性成分中含有多种醛类和酯类化合物,烘烤后产生了大量的烷基吡嗪,其在碱性部分中的相对含量比烘烤前提高14倍多,不饱和醛类化合物含量也有明显提高。南瓜籽油脂中的主要化学成分是油酸、亚油酸及其酯类。还含有生物活性功能成分如植物甾醇、角鲨烯和维生素E等。烘烤后除角鲨烯含量有所降低,维生素E、植物甾醇、亚麻酸等均有提高。  相似文献   

18.
缩氨基硫脲及其环化产物噻二唑的合成及其活性   总被引:13,自引:0,他引:13  
合成了两个缩氨基硫脲及其两个环化产物———1,3,4-噻二唑,考察了噻二唑杂环的闭合条件,测定了产物的部分物理常数及红外光谱,对化合物作了初步抑菌活性筛选。为含有碳氮硫活性中心的金属螯合配体的研究提供了基础  相似文献   

19.
Albumin microspheres and microcapsules containing cisplatin (CDDP) were prepared and tested as chemotherapeutic agents for the treatment of hepatocellular carcinoma. CDDP albumin microspheres were prepared by hardening with glutaric aldehyde in accordance with the method to prepare W/O emulsion. On the other hand, microcapsules were prepared by formation of a coacervate by the phase isolation method. CDDP albumin microspheres and microcapsules thus prepared were sieved and sterilized by dry heat at 135 degrees C for 4h prior to use. The content and release of CDDP were determined. The CDDP contents for albumin microspheres and microcapsules were found to be 9.2% and 33.3%, respectively. Release of CDDP in vitro was found to be significantly different between the two formulations. CDDP release in vivo was also investigated by injecting albumin microspheres and microcapsules into the hepatic artery of adult dogs. The blood CDDP concentrations after injection of both formulations were lower than those noted after injection of CDDP injectable solution, indicating that CDDP might be accumulated in the liver at a higher concentration and that use of the two formulations might result in alleviation of CDDP side effects.  相似文献   

20.
Two new bridged nitraminotriazoles with bridging oxapropylene and nitrazapropylene moieties were synthesized, and converted into several salts, as well as from the hydrazonemethylene bridged nitraminotriazole. All compounds were fully characterized by NMR and IR spectroscopy, elemental analysis as well as differential thermal analysis. The sensitivity towards friction and impact were determined according to BAM standard technics and the energetic properties were calculated by using the EXPLO5 computer code. The neutral compounds as well as the various salts were examined in terms of their physicochemical properties and detonation performance to each other and compared to the commonly used secondary explosive RDX.  相似文献   

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