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本文报道了6种新的丙烯酰胺衍生物的EI谱。在精确质量测量和B/E,B~2/E联动扫描亚稳离子测定的基础上,着重讨论了该类化合物的共同质谱特征:如分子离子失去H_2O的成环反应;产物离子的开环反应;分子内的氢重排反应等。同时,利用Hammett方程讨论了化合物中N-苯基端苯环上不同取代基对特定碎片离子强度的影响  相似文献   

3.
杨小兵  丁松涛  王安邦 《分析化学》2006,34(10):1445-1447
用电子轰击质谱(EI-MS)研究了1,4-氧氮杂萘-2-酮系列衍生物,分析并探讨了不同取代基对这类化合物EI-MS谱图的影响,分析得到一些裂解规律。  相似文献   

4.
付华  王敬尊 《分析化学》1993,21(9):1068-1070
本文采用FDMS和DElMS对4种新型火药进行了质谱分析,均得到了很强的分子离子峰和特征碎片峰,并对样品A进行了DEIMS的亚稳分析,得出了该类化合物的裂解规律为:M-n(NO),M-n(O),M-n(NO_2),M-n(HNO_2),M-n(OH)等。  相似文献   

5.
《Analytical letters》2012,45(12):2661-2666
Abstract

The electron impact mass spectra of fifteen 4-substituted PBN's and PBN itself have been obtained using the probe method. Strong molecular ion peaks were observed in most cases. Fragmentation follows two major pathways depending on the polarity of the substitutent: the tert-butyl bond breaks to produce either the tert-butyl cation or isobutylene. The latter route is analogous to the well known McLafferty rearrangement. Fragmentation to produce the tert-butyl radical is a minor route. Electron-donating polar substituents appear to enhance fragmentation to isobutylene.  相似文献   

6.
The mass spectra of 56 arylpyridines were studied under EI conditions. The fragmentations of this series of compounds are relatively simple because of a stable skeleton containing two aromatic rings. The orientations of cleavage of the methoxyl and methoxycarbonyl groups strongly depend on their position on the pyridine ring and can be applied to the differentiation of the isomers.  相似文献   

7.
孙大勇  刘子阳 《分析化学》1997,25(6):663-666
采用解析电子轰击质谱对电弧法合成的稀土富勒烯衍生物的提取液进行了质谱分析,有效地检测到富勒烯,稀土富勒烯单电荷、双电荷的分子离子峰。利用同位素贡献确证了某些稀土富勒烯的生成。采用高电流瞬间解析样品,使得谱图中的谱峰强度更加真实地反应出提取液中各组分的相对含量。  相似文献   

8.
由氯代丁烯二酰氯和α-氨基苯乙酮的盐酸盐经缩合、关环反应合成了标题化合物Ⅰ、Ⅱ.用元素分析、紫外光谱、红外光谱、质谱鉴定了其结构,并用X射线衍射法测定了Ⅰ的晶体结构,其空间群为P21,晶胞参数α=0.8450(2)nm,b=0.6994(1)nm,c=1.5432(5)nm,β=102.38(2)°,Z=2.由于在烯键碳原子上引入体积较大的氯原子,使Ⅰ和Ⅱ分子的平面性变差,其电子光谱相对于反式-1,2-双[2-5-苯基唑基)]乙烯(POEOP)有蓝移,且荧光量子产率明显下降。  相似文献   

9.
何坚  黄如俊  李刚  唐紫超  林水潮 《分析化学》2012,40(10):1616-1621
常用的气体分析质谱仪使用四极杆质谱作为分析器,分辨率一般低于300,无法解决同质量数离子带来的干扰问题.本实验自行研制了一种小型高分辨气体分析质谱仪,它采用电子轰击离子源反射式飞行时间质量分析器.仪器腔体总长45 cm,在m/z 28的位置,质量分辨率达到3000(Full width at half maximum,FWHM),实现了CO和N2的半峰谷分离;在m/z 69的位置,仪器分辨率达到5000(FWHM).在直接大气压进样条件下,可以检测到空气中136Xe(含量7.8 μ g/m3)和80Kr(含量2.8 μg/m3).使用ADC采集时,仪器的动态范围为1 06.该仪器将作为高端气体质谱仪,应用于过程监测在线分析、环境有机挥发物研究、热分析质谱及催化反应监测等领域.  相似文献   

10.
IntroductionTheeliminationsofCOandCO2fromthemolecularionsofphthalimideanditsN-methyl,N-phenylderivativesinmassspectrometrywer...  相似文献   

11.
对两类非共轭的1,3,4-噁二唑衍生物Ⅰa~e和Ⅱa~e的电子轰击质谱进行了研 究,并通过B/E联动扫描对它们可能的裂解途径进行了探讨。  相似文献   

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Alkyl dinitrites have attracted attention as an important type of nitrosating agent and a pollution source in atmosphere. The reactivity and chemistry of alkyl dinitrites induced by the two ONO functional groups are relatively unknown. In this work, decompositions of 1, 3-cyclohexane dinitrite and 1, 4-cyclohexane dinitrite are studied by electron impact ionization mass spectroscopy (EI-MS). Apart from NO+ ($m/z$=30), fragment ions $m/z$=43 and 71 are the most abundant for the 1, 3-isomer. On the other hand, fragments $m/z$=29, 57, 85, and 97 stand out in the EI-MS spectrum of 1, 4-isomer. Possible dissociation mechanisms of the two dinitrites are proposed by theoretical calculations. The results reveal that the ring-opening of 1, 3-cyclohexane dinitrite mainly starts from the intermediate ion (M-NO)+ by cleavage of two $\alpha$C-$\beta$C bonds. For 1, 4-cyclohexane dinitrite, in addition to the decomposition via intermediate (M-NO)+, cleavage of $\beta$C-$\beta$C bonds can occur directly from the parent cation M+. The results will help to understand the structural related chemistry of alkyl dinitrites in atmosphere and in NO transfer process.  相似文献   

14.
Many four- and six-membered ring rearrangements have been observed under mass spectrometric ionization conditions to date1-7. 1-(Benzyloxycarbonyl)amino-2-alkyl/ cycloalkyl thioacetates are key intermediates for the synthesis of 1-substituted and cyclic t…  相似文献   

15.
用电子轰击质谱(EI-MS)研究了1-烷基-3-甲基-2(1H)-喹喔啉-2-酮(烷基为H,CH3,Et,n-C5H11),1-烷基-3-甲基-6-硝基-2(1H)-喹喔啉-2-酮(烷基为CH3,Et)和1-甲基-3-甲基-6-胺基-2(1H)-喹喔啉-2-酮,结合其结构特征总结出一些裂解规律。讨论了不同取代基对这类化合物熔点的影响,结果表明:在同类喹喔啉化合物中,随着烷基链的增长,样品熔点通常会有所降低,而硝基及胺基的引入会使其熔点升高。  相似文献   

16.
Abstract

The electron impact mass spectra of a series of substituted phenol blocked toluene diisocyanate crosslinkers were analyzed and a suitable dissociative pathway proposed.  相似文献   

17.
宋凤瑞  刘子阳 《分析化学》1998,26(7):865-867
建立了麻醉痛药物的电子轰击/串联质谱分析方法,得到了电子轰击/串联质谱(EI/MS/MS)条件下16种麻醉镇痛药物标准品的碰撞诱导解离(CID0-子离子谱,适合于复杂基质中这类化合物的定性分析,并利用所建方法对一肌注度冷丁者的尿样进行了检测。  相似文献   

18.
本文用CH4作反应气的化学电离法(CIMS)在三级串连四极质谱仪上完成了四对十四碳不饱和醇蒸发量构体的能量分辩质谱研究。目标化合物的CIMS极其相似,它们各自的准分子离子[M-I]^ 的碰撞活化分解谱也差别不大,但在0-50eV的能量分辨质谱显示了顺、反异构信息,文中讨论了导致顺、反异构体的能量分辨质谱差异的原因。  相似文献   

19.
《Analytical letters》2012,45(7):553-565
Abstract

Quadrupole mass spectral analysis of the volatile uranium ligand complex bis (1,1,1,5,5,5-hexafluoro-2,4 pentanedionato) dioxouranium-di-n-butyl sulfoxide is described utilizing electron impact (EI) and methane chemical ionization (CI) ion sources. All major ions are tentatively identified and the potential usefulness of this complex for determining uranium isotope 235U/238U abundance is demonstrated.  相似文献   

20.
The electron impact time-of-flight(TOF) mass spectra of the title compounds were studied to establish their fragmentation processes. With the high resolution of the TOF instrument, the exact mass for each fragment was determined. These data were used to infer the molecular formulas and the elemental compositions for all the molecular ions and fragments through software interpretation. By further applying the fragmentation regularity, the majority of ions were fully assigned. The main fragmentation pathways of the title compounds include the formation of molecular ions by the loss of R^1 groups in the 4-position and the ester groups in the 5-position. The formed ion can be further fragmented by the elimination of MeOH.  相似文献   

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