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51.
Cholesteryl acetate and cholesteryl chloroformate compounds have been irradiated with 60Co-γ rays at room temperatures. The irradiated samples have been examined for paramagnetic resonance, and the observed spectra in several cases have been identified with specific radicals. The results in each case have been considered in relation to the present knowledge of the radiation chemistry of the compound. The single crystals have been investigated between 120 and 300?K. The spectra are found to be temperature independent and radiation damage centers are attributed to ?HCH2 radical for cholesteryl acetate and ?H3 and ?HCH2 CH2 CH2 radicals for cholesteryl chloroformate. 相似文献
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53.
ClO与ClO自由基反应机理及电子密度拓扑分析 总被引:1,自引:0,他引:1
利用密度泛函理论对ClO与ClO自由基反应机理进行了深入理论探讨,在B3LYP/6-311++G(3df)水平上对该反应体系的反应物、中间体、过渡态及产物进行了几何构型优化,对反应通道进行了IRC(内禀反应坐标)路径解析,计算了沿各反应通道的能垒和离解能,并进行了零点能校正.从量子拓扑学的角度,对反应通道IRC途径上一些重要点进行了电子密度拓扑分析,讨论了反应过程中化学键的断裂、生成以及键的变化规律,找到了反应途径的能量过渡态和结构过渡态. 相似文献
54.
空气和废气中ClO2测定方法的研究 总被引:3,自引:0,他引:3
利用KI,H2O,CCl4作吸收溶剂,采用溶液吸收法采集空气和废气中ClO2,吸收后再用紫外分光光度法或滴定法分析,用KI作为吸收剂,以一定的流量采气,采集30min,其采样效率及加标回收率为94.0%-101.5%,从而找出一种较理想的测定方法。 相似文献
55.
合成了两种稀土高氯酸盐与L-脯氨酸配合物的晶体.经热重、差热、化学分析及对比有关文献,知其组成 是[Pr2(L-Pro)6(H2O)4](ClO4)6和[Er2(L-PrO)6(H2O)4](ClO4)6,质量分数为99.24%和98.20%.选用RE(NO3)· 6H2O(RE=Pr,Er)、LPro、NaClO4·H2O和 NaNO3作辅助物,使用具有恒温环境的反应热量计,以 2 mol·L-1HCl 作溶剂,分别测定了[2RE(NO3)3·6H2O+6L-PrO+6NaClO4·H2O]和{ [RE2(L-PrO)6(H2O)4](ClO4)6+6NaNO3}在 298.15 K时的溶解热.设计一热化学循环求得化学反应的反应焓rH分别是:63.904 kJ·mol-1和 91.017 kJ·mol-1,经计算得配合物[RE2(L-Pro)6(H2O)4](ClO4)6(s)在 298.15 K时的标准生成焓(298.15 K)分别 是-6 594.78 kJ·mol-1和-6 532.87 kJ·mol-1。 相似文献
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高氯酸镁催化合成1,2,3,4-四氢嘧啶-2-酮 总被引:9,自引:0,他引:9
在高氯酸镁催化作用下,由醛、1,3-二羰基化合物、脲(硫脲)合成了一系列1,2,3,4-四氢嘧啶-2-酮,此合成方法反应温和、产率高,并且高氯酸镁具有能重复使用的优点. 相似文献
57.
The matrix isolation technique with Fourier transform infrared detection has been applied to determine the products of gaseous radical reactions. The gas phase reactions were carried out in a discharge flow system and about 1% of the gas mixture was deposited onto a low temperature target through a pinhole. A differential pumping scheme was employed to maintain the pressure of the cryosystem below 10?5 torr while that of the flow system was kept at about 2 torr. Species including HO2 (from the H+O2 reaction), ClO2 (from the Cl+O2 reaction) and ClO (from the Cl+O3 reaction) have been produced in the gas phase and were successfully trapped in matrices and detected with an FTIR spectrometer. In addition, both HCl and HOCl have been detected as the reaction products from the gaseous ClO+HO3 reaction. The production of HCl from the ClO+HO2 reaction may have a significant impact on catalytic ozone destruction in the atmosphere. 相似文献
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用FeCl3·6H2O与C60(含C70)固体混合,经研磨得含C60(C70)的络合物[Fe(C60)]·ClO和[Fe(C70)]·ClO,该物呈棕黑色,具有吸水性 相似文献
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合成了稀土高氯酸镝-谷氨酸配合物晶体。经热重、差热、化学分析及对比有关文献,确定了其组成是Dy2(Glu)2(ClO4)4.9H2O, 纯度是96.54%。选用Dy(NO3)3.6H2O,L-Glu,NaClO4.H2O和NaNO3作辅助物,使用具有恒温环境的反应热量计和热化学手段,以2mol/L HCl作溶剂,分别测定了[2Dy(NO3)3.6H2O+2Glu+6NaClO4.H2O]和[Dy2(Glu)2(ClO4)4.9H2O+6NaNO3]在25℃时的溶解焓。通过设计热化学循环求得化学反应的反应焓ΔrHΘm, 25℃=234.300kJ/mol, 计算得到配合物Dy2(Glu)2(ClO4)4.9H2O(s)在25℃时的标准生成焓ΔfHΘm, 25℃=-6476.116kJ/mol。 相似文献
60.
Ga(ClO4)3-catalyzed reaction of 1,2-aryldiamines and α-bromoketones to afford 2-substituted quinoxa- lines in good yields is described. The reaction proceeded via grinding process with 10%(molar fraction) catalyst under solvent-free conditions at room temperature. For unsymmetrical o-phenylenediamines bearing electron-with- drawing groups, regio-selective quinoxalines were obtained. 相似文献