己二酰肼脂肪族双酰基衍生物的电子轰击电离质谱特征

前文曾报道了己二酰二肼脂肪族双酰基衍生物的金属减活作用 [1] ,在研究中还发现该类化合物在电子轰击电离 (EI)条件下的质谱裂解行为具有特征的规律 .因为 ,在已研制和开发的酰肼类金属减活剂中 ,— NHNH—的封端为芳环者较多 ,为脂肪族碳链者甚少 [2 ,3 ] ;而且该类化合物还是合成具有生物活性及电子传输功能的双 - 1 ,3 ,4-二唑的重要前体 ,正在重新引起重视 [4 ,5] ;再则它们的溶解性普遍很差且使用时浓度较小 ,所以关于该类化合物结构表征的波谱学研究并不多见 .本文报道了己二酰肼脂肪族双酰基衍生物的 EIMS特征 ,对于该类化合…     

己二酰二肼脂肪族双酰基衍生物的金属减活作用

二酰基己二酰二肼;聚丙烯;己二酰二肼脂肪族双酰基衍生物的金属减活作用     

N,N′-二芳基己二酰二肼类化合物的合成及其结构表征

报道了N,N′-二芳基己二酰二肼类化合物的合成方法。以自制的己二酰二氯、取代苯肼为原料,以二氯甲烷为溶剂,用冰浴法合成了9种新型的N,N′-二芳基己二酰二肼类化合物。产品的结构经元素分析、IR、1HNMR等测试技术得到确证,产物的IR谱中,在3 200～3 400 cm-1出现2个N—H吸收峰,1H NMR谱中,在δ7.3～10.5之间有2个N—H吸收峰,产品的元素分析结果与理论值基本相符。收率81%～93%。     

N,N''''-二芳基己二酰二肼类化合物的合成及其结构表征

报道了N,N'-二芳基己二酰二肼类化合物的合成方法.以自制的己二酰二氯、取代苯肼为原料,以二氯甲烷为溶剂,用冰浴法合成了9种新型的N,N'-二芳基己二酰二肼类化合物.产品的结构经元素分析、IR、1HNMR等测试技术得到确证,产物的IR谱中,在3200～3400 cm-1出现2个N-H吸收峰,1H NMR谱中,在δ7.3～10.5之间有2个N-H吸收峰,产品的元素分析结果与理论值基本相符.收率81%～93%.     

N,N′-二芳基己二酰双偶氮化合物的合成及其结构表征

N;N′-二芳基己二酰二肼;N;N′-二芳基己二酰双偶氮化合物;合成     

双(1,4-二酰基氨基硫脲)化合物的合成

酰氨基硫脲及其相关化合物通常具有广泛的生物活性 ,如抗菌[1～ 3] ,抑制神经紧张[4] ,治疗血糖过低[5] ,植物生长调节[6～ 9] 等。迄今为止 ,鲜有关于双 (1 ,4 二酰基氨基硫脲 )合成的报道。为了考查该类化合物的生物活性 ,我们设计合成了一系列双 (1 ,4 二酰基氨基硫脲 )化合物 ,以下图所示的两条合成路线合成了该类化合物 :二酰氯 (1 )、异硫腈酸酰酯 (2 )等中间体可不经进一步纯化直接用于下一步反应。所生成的产物 3ａ 3ｆ、3′ｄ 3′ｇ经ＤＭＦ Ｈ2 Ｏ ＥｔＯＨ重结晶 ,产率达 81 %～ 98%。在合成化合物 (1 )时 ,对于一些用ＳＯＣｌ2 …     

α-亚磺酰基-N,N-二取代酰胺的简便合成

合成了6个未见文献报道的α-亚磺酰基-N，N-二取代酰胺，比较了使用各种氧化剂将α-烷硫基-N，N-二取代酰胺氧化成目标分子的条件，从而提供了一条简捷的合成路线。     

N—环已基吡嗪酮类化合物的EI质谱及其解析

总结和归属了（2H）－2－环已基－3，4二氢吡咯并[1,2-α]吡嗪－1－酮及其7个苯甲酰基衍生物和3个苯乙酰基衍生物在电子轰击电离质谱（EI－MS）中的主要裂解方式和特征，指明了主要碎片离子的来源和结构，这10个芳酰基衍生物质谱图中的主要碎片峰均来自麦氏重排和异构化后的α－裂解，由其裂解产生的m/z120和m/z163离子是该类化合物共同的特征离子；吡嗪酮苯甲酰基衍生物基峰为M－82，苯乙酰基类衍生物基峰为m/z245。     

Calibration Point for Electron Ionization MS / MS spectra measured with multiquadrupole mass spectrometers

A protocol for establishing standard instrument conditions for measurement of product ion MS/MS spectra from parent ions produced by electron ionization is presented. Within this protocol, the ion at m/z 231 (C₅F₉ ⁺) from perfluorokerosene or perfluorotributylamine is selected as the parent ion and subjected to collision-induced dissociation. The relative intensities of product ions at m/z 69, 131, and 181 are monitored as a function of collision energy while keeping the target gas pressure constant within the range of 10^?4–10^?6 torr (measured), or a beam attenuation of approximately 30-70%. The collision energy at which the ion intensities for product ions at m/z 69 and 181 are equal is defined as the calibration point at that collision gas pressure; the intensity of the ion at m/z 131 is very close to this value as well. Electron ionization MS/MS spectra taken at the calibration point using two different multiquadrupole instruments show good reproducibility for several test compounds. The high degree of similarity may aid in the establishment of a MS/MS spectral library.     

Fragmentation of Some Substituted Phthalimides on Electron Impact Ionization

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Characteristics of the Dissociative Ionization of 9-Aryl(hetaryl)-3,3,6,6-tetramethyldecahydroacridine-1,8-diones under the Influence of Electron Impact

The mass spectra of 9-aryl(hetaryl)-3,3,6,6-tetramethyldecahydroacridine-1,8-diones have been studied and the basic directions of their dissociative ionization under the influence of electron impact have been elucidated. It has been shown that the decomposition pathways of decahydroacridine-1,8-diones depend on the nature of the substituents at position 10 and is connected with the preferential formation of a pyridinium structure with subsequent retrodiene decomposition of the molecules.     

Relative Cross Sections for L- and M-Shell Ionization by Electron Impact

 Results from measurements and calculations of relative L- and M-shell ionization cross sections by electron impact are presented. Measurements were performed for elements Te, Au and Bi on an electron microprobe with specimens consisting of extremely thin films of the studied element deposited on thin, self-supporting, carbon layers. The relative variation of the ionization cross section was obtained by counting the number of characteristic X-rays from the considered element and shell, for varying incident electron energies, from the ionization energy up to 40 keV. Measured data were corrected to account for the energy-dependent spread of the electron beam within the active film and for the ionization due to the electrons backscattered from the carbon layer, using Monte Carlo simulation. Cross sections were evaluated in the Born approximation using an optical-data model with numerically evaluated dipole photoelectric cross sections. Calculated ionization cross section were converted to vacancy production cross sections, which can be directly compared with our experimental data.     

Electron Impact and Chemical Ionization Mass Spectral Analysis of a Volatile Uranyl Derivative

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 235_U/238_U abundance is demonstrated.     

Identification of Fragment Ions by Their Kinetic Energy Gained During Dissociative Ionization by Electron Impact

A technique is described, which supports the plasma mass spectrometry to distinguish possible sources of ion peaks found in the mass spectrum of the neutral gas. The proposed method is based on the measurement of the kinetic energy which the fragment ions gain during dissociative ionization by electron impact inside the ion source of the spectrometer. This approach is of special interest for applications in plasma processes such as plasma assisted deposition or etching techniques where complicated molecules are involved. The principle of the method is demonstrated and discussed for the examination of various fragment ions as CH₃ ⁺, C₂H₂ ⁺, C₂H₃ ⁺, C₂H₅ ⁺ and CH₃O⁺ in the neutral gas spectrum of an 13.56 MHz rf discharge in an Argon-Tetraethoxysilane (TEOS) mixture.     

超声辐射快速合成偶氮取代苯甲酰氯

超声辐射下,以偶氮取代苯甲酸为原料,氯化亚砜为氯化剂,合成了8种偶氮取代苯甲酰氯系列产物。与普通加热搅拌法相比,反应时间由12h缩短至4h,收率达80%～95%。目标化合物结构经红外光谱、核磁共振和元素分析测试技术得到确证。     

Mass Spectrometric Fragmentation of 1-（Benzyloxycarbonyl）amino-2-alkyl/cycloalkyl Thioacetates： a Thioester Pyrolysis-type Rearrangement under Electron Impact Ionization

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…     

N-Isopropenylazoles: II. Fragmentation of N-Isopropenylazoles under Electron Impact

Fragmentation under electron impact of all N-isopropenylazoles, except for N-isopropenyl-2- phenylpyrrole, involves elimination of propyne or allene with formation of the corresponding NH azoles. N-Isopropenylpyrrole, N-isopropenyl-4,5,6,7-tetrahydroindole, and N-isopropenylindole give rise to rearrangement of the molecular ion into azepine structure, while the fragmentation of N-isopropenyl-2-phenylpyrrole is accompanied by transfromation into 5-methyl-5,6-dihydropyrrolo[2,1-a]isoquinoline. Retrodiene decom- position is the main fragmentation pathway of the molecular ions derived from N-isopropenyl-4,5,6,7-tetrahydroindole and its 2-methyl-substituted analog. In the decomposition of 2,3-di- and 2,3,5-trimethyl-N-isopropenylpyrrole, the major fragment ions are formed from the [M - H]⁺ ion having a pyridinium structure rather than from the molecular ion. N-Isopropenyldi- and -triazoles undergo fragmentation along competing pathways involving cleavage of the heteroring.