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121.
卟啉超分子化合物在分子器件中的应用   总被引:1,自引:0,他引:1  
分子电子器件已成为近年来的一个研究热点,卟啉类化合物因为光敏性好、性能稳定、易于修饰等优点成为分子器件研究的理想模型化合物。本文着重介绍了它在分子器件中的最新应用进展。  相似文献   
122.
富勒烯四甲氧基衍生物的合成与表征甘良兵,周胜,姜剑峰,黄春辉(北京大学化学与分子工程学院,北京,100871)武轶,吕木坚,潘景歧(北京微量化学研究所)(北京大学分析测试中心)关键词C_60衍生物,甲氧基,四氮杂环十二烷富勒烯化学是目前人们研究的热门...  相似文献   
123.
A method for the direct determination of pefloxacin in serum and pharmaceutical forms (tablets and ampoules) has been developed, based on the use of second-order derivative ultraviolet spectra. Spectrophotometric assay of pefloxacin in tablets and ampoules was carried out in 0.1 mol/L NaOH, while in serum it was performed in 0.1 mol/L NaOH with the addition of sodium dodecylsulfate, in 337–347 nm wavelength range. Linear calibration curves were obtained in the concentration ranges 2–30g/mL pefloxacin for tablets and ampoules and 0.12–5 g/ mL for serum samples. Relative error of determination, as criterion for accuracy, was less than 1%, while the precision was better than 4 ng/ml. The minimum detectable concentration of pefloxacin in serum was 15 ng/mL.  相似文献   
124.
Thiourea derivative‐based carbon paste electrode (TUD1‐CPE) was constructed as a potentiometric sensor for the determination of salicylate anion in pharmaceutical formulations, Aspocid® and Aspirin®. The optimized CPE contained 45.5 % graphite, 0.5 % reduced graphene oxide (rGO), 46.0 % nitrophenyl octyl ether (NPOE) plasticizer, 5.0 % TUD1 ionophore, and 3.0 % tridodecylmethyl ammonium chloride as additive. The incorporation of NPOE of high dielectric constant, and rGO in electrode caused better performance of the sensor; Nernstian response of 59.0 mV decade?1 in the concentration range of 10?1–10?5 mole L?1, a detection limit of 1×10?5 mole L?1 in a very short response time of 6 seconds. The prepared sensor showed high selectivity against similar anions (i. e. , benzoate, I?, SCN?). Selectivity was confirmed by calculating the formation constant (Kβ) using sandwich membrane method, where Kβ for TUD1‐salicylate is 100.43. Theoretical calculations at DFT‐B3LY/6‐31G** level of theory were performed to find interaction mechanism, Energies of HOMO and LUMO orbitals, non‐linear optical (NLO) properties (the electronic dipole moment (μ), first‐order hyperpolarizability (β), the hyper‐Rayleigh scattering (βHRS) and the depolarization ratio (DR)), and other global properties; these calculations showed lower values of β and DR, higher value of βHRS, and the shortest lengths of the four N?H bonds between TUD1 and salicylate which confirm their strong complexation and salicylate‐selectivity. Also, all the studied anion‐TUD1 exhibited relatively high NLO properties, and these results were considered as a preliminary study for investigating new types of NLO bearing materials. The sensors were applied successfully for the determination of salicylate anion in Aspocid® and Aspirin®.  相似文献   
125.
手性环丙烷类衍生物双水解转换的研究   总被引:3,自引:0,他引:3  
具有四个新手性中心的螺环/环丙烷类化合物4在丙酮-12%HCl溶液中50℃下 发生双手性辅基-双水解转换反应,得到了手性环丙烷/双半缩醛类化合物,螺 [1-溴-4-羟基-5-氧杂-6-氧代双环[3.1.0]己烷-2,2′-(3′-亲核氧基- 4′-羟基丁内酯)](5),化学产率65%-79%,光学纯度ee≥98。通过元素分 析,[a]D^20,UV,IR,^1H NMR,^13C NMR,MS以及X射线四圆衍射测定,确认了它们的 化学结构、立体化学和绝对构型。该双半缩醛类化合物的合成方法学研究可为官能 团的转换,为某些复杂结构的手性化合物提供新的合成方法和途径。  相似文献   
126.
合成了全戊基化(Ⅰ)和部分戊基化三氟乙酰化(Ⅱ)的两种“环糊精手性固定相。将它们分别与OV-7混合制备出柱效大于4100塔片/m,热稳定性可达210℃的手性石英毛细管住。对映体拆分结果表明,固定相Ⅰ对醇、二醇、胺、γ-内酯等对映体比Ⅰ有更高的选择性。  相似文献   
127.
二阶导数差示脉冲极谱法用于醋酸氟氢可的松的定量研究   总被引:2,自引:0,他引:2  
用二阶导数差示脉冲极谱法对醋酸氟氢可的松进行了定量分析。在0.001mol/L硫酸+乙醇+水(1+25+24)的底液中,醋酸氟氢可的松于-0.340V(vsAg/AgCl)处出现一良好的二阶导数差示脉冲极谱峰,在5~140μg/mL范围内,醋酸氟氢可的松的浓度与其二阶导数差示脉冲极谱峰幅值呈线性关系,检测限为0.4ng/mL。本法操作简便、快速、灵敏、结果准确。  相似文献   
128.
In this paper, 2-(2′-hydroxy-phenyl)-4(3H)-quinazolinone (HPQ), a typical compound that exhibits excited state intramolecular proton transfer (ESIPT) reaction and possesses good photophysical properties, is synthesized and used as fluoroionophore for Fe3+ sensitive optochemical sensor. The decrease of fluorescence intensity of HPQ membrane upon the addition of Fe3+ was attributed to the blocking of ESIPT reactions of HPQ and quenching its fluorescence. The effect of the composition of the sensing membrane was studied, and experimental conditions were optimized. The sensor shows a linear response toward Fe3+ in the concentration range of 7.1 × 10−7 M to 1.4 × 10−4 M with a limit of detection of 8.0 × 10−8 M, and a working pH range from 2.5 to 4.5. It shows excellent selectivity for Fe3+ over a large number of cations such as alkali, alkaline earth and transitional metal ions. The proposed sensor is applied to the determination of the content of iron ions in pharmaceutical preparations samples with satisfactory results.  相似文献   
129.
Design and Synthesis of Glycosylated Aromatic Nitrogen Mustard Derivatives   总被引:3,自引:0,他引:3  
Antibody-directed enzyme prodrug therapy(ADEPT) is a new strategy for the treatment of cancer that has arisen in recent twenty years, the main merits of which are that it can improve the selectivity of anticancer drugs and reduce the side effects in remote tissue. In the present study, two prodrugs-glycosylated aromatic nitrogen mustard derivatives were synthesized. Glucose and lactose were converted into glycosyl donors-trichloroacetimidate; the obtained glycosyl donors were glycosylated with p-nitrophenol(glycosyl donors) to form β-glucosyl p-nitrobenzene and β-lactosyl p-nitrobenzene that were protected by acetyl in a stereoselective manner; the two products were reduced by zinc dust and then treated with ethylene oxide, afforded two glycosylated nitrogen mustard derivatives that were protected by acetyl; the last step was to deacetylate and then afforded the two target compounds that could be used as prodrugs of ADEPT for further Anti-tumor research.  相似文献   
130.
吴范宏  顾松  黄维垣 《有机化学》2006,26(5):671-675
以连二亚硫酸钠为引发剂, 烯丙基丙二酸二乙酯与多氟烷基碘代烷在温和反应条件下反应, 方便地得到一系列多氟烷基取代的环丙烷衍生物, 产率45%~55%. 在相同条件下, 烯丙基乙酰乙酸乙酯与多氟烷基碘代烷反应得到相应的加成物, 加成物随后用碱处理也得到环合的产物.  相似文献   
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