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1.
本文首次报导了Ln(OOCCF_3)_3(Ln=Pr,Nd,Sm,Eu,Gd,Tb,Ho,Er,Tm,Yb,Lu)在甘油中的正负离子FAB谱,总结并讨论了其谱图特征。通过亚稳离子分析,探讨了某些离子碎裂和形成途径,提出了Ln(Ⅲ)→Ln(Ⅰ)可能的还原变价机制。  相似文献   

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本文介绍 FAB 质谱的原理,功能和优点,综述了 FAB 机理,讨论了影响 FAB 谱的因素,归纳了 FAB 法在金属有机络合物研究中的应用。  相似文献   

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苯基重氮盐质谱研究曾有报导,它同冠醚分子形成的嵌合物质谱也被测定过。本文采用快原子轰击(FAB)研究了苯基重氮盐,(R=OCH_3,CH_3,H,Br,Cl,F,NO_2)同18-冠醚-6以及二苯并-24-冠醚-8形成分子嵌合物的质谱(MS),讨论这类嵌合物准分子离子MNa~ 丰度同嵌合物内授-受键的性质之间的关系,并由分子轨道方法计算结果解释了MNa~ 的丰度同苯基重氮盐上取代基R性质的关系。  相似文献   

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本文报道十余个冠醚稀土络合物的快原子轰击质谱(FABMS)。通过分析FABMS的特征及亚稳离子分解讨论了溶液中的反应和络合性质。  相似文献   

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Abstract

The low resolution mass spectra of alkyl and aryl sulfinamides containing alkyl, cycloalkyl, aryl and cyclic amine functions were recorded and the major fragmentation modes were elucidated with the aid of metastable peaks. In addition, the behavior of a variety of sulfinate esters upon electron-impact was similarly established.  相似文献   

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We have systematically studied redox properties of two series of several dozen heteropoly acids (salts) and their derivatives with vanadium and rare-earth elements with Keggin and Dawson structures, e. g. LnHSiMo_(12), SiMo_(12-n)V_n, M_(1.5)PMo_(12), PMo_(12-n)V_n, PW_(12-n_V_n, Ln(PMo_(11))_2, Sm(XMo_(11))_2 and P_2Mo_(18-n)V_n, etc., and obtained their sequence of oxidation. It was found that there is a linear relationship between the reduction potentials of heteropoly anions and the derivatives of heteropoly anions with rare-earth elements with Keggin structure and nq~2 (n and q are the principal quantum number and charge of the central ion respectively). On the basis of the electrostatic model the regularity of oxidation and reduction was rationalized.  相似文献   

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甜叶醇衍生物的合成及其生物活性   总被引:2,自引:0,他引:2  
本文对甜叶醇的结构进行修饰合成14个新化合物。其中以化合物4对棉花种子的发芽及根促进作用最佳。  相似文献   

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Abstract

The mass spectral fragmentation of thiophenotropone, thiophenotropilidene derivatives and their iron and chromium tricarbonyl complexes are fully reported and discussed. The fragmentation patterns of the complexes are characterised by successive loss of three carbonyl groups. In general, the resulting ions after elimination of the metal behave in the same manner as the organic ligand. The iron complexes behave differently from their corresponding chromium complexes. The thiopheno[b]tropilidene iron tricarbonyl complex and its isomer thiopheno[c]tropilidene iron tricarbonyl complex could not be differentiated by mass spectrometry, such differentiation was achieved by proton magnetic resonance.  相似文献   

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A series of estrone derivatives of amino acids and peptides haze beensynthesized by different coupling reagents and the binding affinity of deblocked derivativesto the estrogen receptor of rats uteri have been measured by a comptetive radiometric bind-ing assay.  相似文献   

13.
肝素化聚甲基丙烯酸的合成及抗凝血性能的研究   总被引:1,自引:0,他引:1  
本工作采用四价铈盐作引发剂,进行了甲基丙烯酸在肝素上的接枝聚合,合成了肝素化的交联型聚甲基丙烯酸,并对接枝聚合的反应条件及接枝聚合物的抗凝血性能进行了研究.实验结果表明,肝素化的聚甲基丙烯酸具有优良的抗凝血性能,是一种很有应用前景的新型聚合物.  相似文献   

14.
王娟  赵彤 《高分子学报》2012,(2):103-110
酚醛树脂分子量及分布的表征方法有很多,如蒸气压渗透法(VPO)、气相色谱、高压液相色谱和凝胶渗透色谱等,但由于酚醛树脂存在众多异构体,这些方法均有一定限制性.场解吸质谱(FD-MS)方法的特点是只给出样品固有组分的分子峰,不产生碎片离子峰,用于酚醛树脂的表征,可以直接得出树脂所有固有组分的分子离子峰值,及树脂不同缩合度组分的相对含量,非常适用于组份繁多的酚醛树脂的的分子量及分布表征研究.以苯酚、甲酚及甲醛等原料分别制备了Resole型苯酚-甲醛树脂、Novolac型苯酚-甲醛树脂、Novolac型甲酚树脂及混酚-甲醛树脂,利用FD-MS对制备的几种不同类型酚醛树脂的分子量及分布进行了研究.结果表明,通过FD-MS谱图分析还可以得到树脂缩聚程度、原料种类、树脂特性等信息,对于鉴别及剖析各种类型酚醛树脂方便有效.  相似文献   

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微柱高效液相色谱和质谱法测定烟草样品中多酚   总被引:4,自引:0,他引:4  
研究了用微柱高效液相色谱和质谱法测定烟草样品中植物多酚。烟草样品中植物多酚用80%的甲醇加热回流提取,提取液用Sep-Pak-C18固相萃取小柱预分离脱脂,以WatersXterraTMRP18(1.0mm×50mm,2.5μm)微柱为固定相,甲醇和1%的乙酸梯度洗脱为流动相分离;用紫外二极管矩阵检测器检测,并用质谱对未购到标样的绿原酸异构体进行了辅助定性。方法用于一些烟草样品中多酚的测定,回收率在97%-103%之间,RSD在1.4%-1.9%之间。  相似文献   

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Some new, 2-[(N-substituted aminothiocarbonylthio)acetyl]aminothiazole, N-substituted aminothiocarbonylthioacetylaminodiphenylmethane and 9-[(N-substituted aminothiocarbonylthio)acetyl]aminofluorene derivatives were synthesized by reacting 2-(chloroacetyl) aminothiazole, chloroacetylaminodiphenylmethane, and 9-(chloroacetyl)aminofluorene with secondary amine dithiocarbamate derivatives in acetone respectively. The structure elucidation of the compounds was performed by IR, 1H-NMR, and FAB+-MS spectral data. The substances were tested for their antimicrobial activity.  相似文献   

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<正> Mass spectra of Roussinate anions in K+, Me4N+ and Bu4N+ salt have been obtained under appropriate operating conditions and the fragmentation pathways are proposed based on linked scan information of metastable transition in 1st FFR. and precise mass determinations. It was found that the skeleton structure of the red Roussinate anion is more stable than that of black Roussinate anion.It is interesting to note that rearrangement reaction with transfering of methyl radical in tetramethyl amonium to bridged sulfur atom occurs during evaporation of [(CH3)4N]2 [Fe2S2(NO)4] , forming Roussin's red methylester:In this paper we will provide some significant information in regard to the rationalization of the interconversion reaction between Roussinate anions under certain condition.  相似文献   

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Abstract— In frozen aqueous solutions at 777deg;K, U.V. irradiation (Λ>250 mμ) photoionises purine, adenosine and guanosine molecules, respectively, In alcoholic solutions, at 777deg;K, photosensitization of alcohol occurs. A biphotonic absorption process involving the lowest triplet state is suggested. The formation of radicals by these processes leads to a decrease of the phosphorescent triplet-state population of the molecules tested. Some consequences for the photochemistry of nucleic acids are discussed.  相似文献   

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