2,4—二氨基—5—取代苄基嘧啶类质谱研究

报道了8个2,4-二氨基-5-取代苄基嘧啶衍生物的电子轰击质谱及碰撞活化解离和质量分析离子动能谱.该谱提供了化合物醚键及2,4-二氨基-5-取代苄基嘧啶环的主要碎裂途径,总结了一些裂解规律,将有助于这类化合物的结构推断。     

气相二茂铁双电荷离子的动能谱研究

The unimolecular charge separation reactions of the doubly charged ions FeC_(10)H_(10)~(2+)、FeC_(10)H_9~(2+)、FeC_(10)H_8~(2+) produced in the ion source by electron impact from ferrocene have been studied using Mass analyzed Ion Kinetic Energy Spectrometry (MIKES) technique. From the values of the kinetic energy releases (T), the intercharge distances (R) of the exploding doubly charged ions in their transition structures have been estimated and some structural informations about the transition states can be obtained. The collision induced reactions of the FeC_(10)H_(10)~(2+) ion with Ar have been studied using MIKES, we postulate a new type of continuing reaction which may be "collisional charge separation induced dissociation".     

双电荷离子[C12H12N2O]2+和[C12H12N2S]2+的气相单分子分解反应研究

The unimolecular dissociation reactions of doubly charged ions were reported,which resulted from a tandem mass spectrometer and a reversed geometry double focusing mass spectrometer by electron impact.Mass analyzed ion kinetic energy spectrometry(MIKES) was used to obtain the kinetic energy releases in charge separation reactions of doubly charged ions.The intercharge distances between the two charges at transition states can be calculated from the kinetic energy releases.Transition structures of unimolecular dissociation reactions were infered from MIKES and MS/MS.     

气相二茂铁双电荷离子的动能谱研究

气相双电荷离子及其电荷转移反应在电离层化学、等离子体化学、激光及热核聚变等领域都起非常重要作用。近年来,关于双电荷离子的研究逐年增多,但多数集中在简单的正构烷烃、烯烃、胺和芳香化合物.金属有机化合物的双电荷离子的研究少见报导.Schwarz等人初步探讨了二茂铁双电荷分子离子的单分子电荷分离反应,发现了反应(b)是主要的通道。     

Fragmentation Mechanism of Trans—α—Aryl—β—enamino Esters

Electron impact-induced fragmentation mechanism of Trans-α-Aryl-β-enamino esters were investigated using mass-analyzed ion kinetic energy (MIKE) spectrometry and high resolution accurate mass data It was found that the main characteristic fragmentations of compounds studied were:an odd electron ion M^ -EtOH was formed by losing a neutral molecule of ethanol;and the skeletal rearrangements took place;and the ring opening reaction happened after losing a carbon monoxide;and the typical McLafferty rearrangement underwent in ester group.The cycliztion reation caused by losing neutral molecule of TsNH2 due to the ortho-effects of substituted group of gromatic ring was also observed.     

双电荷离子［C_（12）H_（12）N_2O］~（2＋）和［C_（12）H_（12

双电荷离子［Ｃ_（１２）Ｈ_（１２）Ｎ_２Ｏ］~（２＋）和［Ｃ_（１２）Ｈ_（１２）Ｎ_２Ｓ］~（２＋）的气相单分子分解反应研究任达，贾维平，李智立，刘淑莹（中国科学院长春应用化学研究所，长春，１３００２２）关键词双电荷离子，质量分析离子动能谱，串联质谱，４...     

二乙胺合三(2-苯骈噻唑基)硼烷在电子电离质谱中的反应

在研究二乙胺合三(2-苯骈噻唑基)硼烷的EI质谱时,发现了在EI条件下三(2-苯骈噻唑基)硼烷的二聚作用,并用高分辨质谱、FAB质谱证实了二聚体的存在。用MIKE谱阐明了二聚体离子主要的裂解途径。提出了二聚体形成的一种机理及其可能的结构。     

Skeletal Rearrangement of Substituted Benzaldoxime 3- (2,2-Dichlorovinyl)-2,2-dimethyl Cycle-propane Carboxylates under EI-MS

Introduction Substituted benzaldoxime 3-( 2, 2-dichlorovinyl )-2,2-dimethyl cyclopropanecarboxylates,considered as pyrethroid analogs, show a good bioactivity such as fungicidal, herbicidal and plantgrowth regulating activities[1,2]. EI-MS spectra of those compounds show the rearrangement of their structures, which has prompted us to elucidate their behavior under EI conditions. All the compounds studied have M-165 and M-99 fragment ions in the EI-MS spectra, but there is no segment with the mass of 165 and 99 lost directly from the molecular ions. So we postulated the process of rearrangement, it involved the cleavage of the C2C3 bond in the substituted cyclopropyl accompanied by the migration of disubstitued methylene-amino moiety to C2 or C3 position and elimination of a conjugated group with the mass of 165 or 99 to afford the even electron ion, of which the important step is the cleavage of the N-O bond. Although the cleavage of the alkoxy bond in the pyrethroids[3-5] has been reported, there has been no rearrangement reported. In order to test our postulations, MIKES and EI-HR-MS were carried out to elucidate the fragmentation pathways. The substituents in the phenyl ring played important roles in the stabilization of the product ions. The focal point of our work was to investigate two pathways of the skeletal rearrangement and the effect of the substituents.     

多肽的快原子轰击和质量分离离子动能谱法分析

本文报道了用快原子轰击与质量分离离子动能谱(FAB-MIKES)技术测定三个多肽(七肽、八肽和九肽)中氨基酸的顺序。通过解释谱图上的肽段质子化的离子峰和碎片峰,证明用本项技术测得的氨基酸顺序与已知的完全一致。     

Application of Mass Spectrometry/Mass Spectrometry (MS/MS) to the Identification of Natural Products in Psilocybe Cyanescens

Abstract

Temperature profiling of MIKE spectra allows identification of protonated psilocin in the presence of other compounds with the same mass. The use of multiple ionizing methods to give ions (M+H)⁺, (M+ML₄)⁺, and M is shown to assist in determining the molecular weights of new natural products. Structural information is obtained from the MIKE spectra. All these determinations can be made on the intact mushroom or its simple alcoholic extracts.