大气压化学电离质谱分析苯二苯硫醚异构体  

Analysis and Differentiation of bis (phenylthio) Benzene Isomers by Atmospheric Pressure Chemical Ionization-Mass Spectrometry

作　　者：王陈璐 莫雅雯 曹小吉[2] 莫卫民[1,2] 

机构地区：[1]浙江工业大学化学工程学院,浙江杭州310014 [2]浙江工业大学分析测试中心,浙江杭州310014

出　　处：《质谱学报》2017年第2期169-176,共8页Journal of Chinese Mass Spectrometry Society

基　　金：浙江省公益性技术应用研究计划项目(2010C33074)资助

摘　　要：芳香性苯基硫醚是用于合成具有生物活性的含硫杂环物质的重要前体化合物。本工作采用大气压化学电离(APCI)/离子阱二级质谱技术结合量子化学密度泛函理论计算,对邻、间、对苯二苯硫醚三类位置异构体的质谱裂解反应机理进行研究。苯二苯硫醚三类位置异构体经过碰撞诱导解离(CID),发生HS自由基和苯硫自由基的中性丢失;并且仅在邻苯二苯硫醚类化合物中可观察到连续中性丢失2个HS自由基产生的碎片离子,而在间、对苯二苯硫醚类化合物中则观察到S2的特征丢失;取代苯硫酚的中性丢失只能在邻、间苯二苯硫醚类化合物中检测到,此外,间苯二苯硫醚类化合物还有取代苯的特征性丢失。综上,三类苯二苯硫醚位置异构体在APCI-MS/MS条件下的质谱裂解行为有显著差异,根据HS自由基、S2、取代苯硫酚和取代苯的特征丢失,可实现这些异构体的区分鉴定。Compounds contain sulfur and their relevant derivatives are applied universally in the fields of chemistry, biochemistry, life science and so on. Among them, aryl thioethers are potential useful precursors for constructing various biological active of sulfur-containing heterocycles. Thus, researches for phenyl sulfides have received more and more concern. In this work, gas phase fragmentation reaction mechanism of three kinds of bis （phenylthio） benzene isomers was studied by atmospheric pressure chemical ionization in positive ion mode combined with ion trap mass spectrometer. Meanwhile, theoretical calculations were performed by the density functional theory （DFT） method at the B3LYP level with 6.31＋G （d, p） basis set in the Gaussian 03 package to verify cleavage pathways. Under the positive ion mode, all compounds generated molecular ions firstly, and after collision-induced dissociation （CID）, some interesting fragmentation behaviors were observed. Benzensulfur radical loss resulted from direct heterolytic cleavage of C—S bond and neutral elimination of HS radical were obtained among all compounds. For o-bis （phenylthio） benzenes, loss of HS radical was induced by radical delocalization, followed by cycloaddition and a serious of rearrangements. Moreover, continuous loss of HS radical appeared via similar fragmentation pathway with that of single HS radical loss. In addition, elimination of substituted benzenethiol was also detected, which was triggered by nucleophilic substitution, with H radical shift in the formed ion-neutral complex intermediate going after. For m-bis （phenylthio） benzenes, similar dissociation pattern leading to neutral elimination of HS radical was proposed, among which 1, 4-H proton transfer instead of thioketone-thiophenol interconversion resulted in substituted benzenethiol loss. In the case of neutral HS radical loss existed in p-bis （phenylthio） benzenes, reaction mechanism mediated by cycloaddition was illustrated as well. However, because of the l

关 键 词：大气压化学电离质谱(APCI-MS) 苯二苯硫醚 碰撞诱导解离(CID) 裂解机理 位置异构体 理论计算 

分 类 号：O657.63[理学—分析化学]