基于真空紫外光电离质谱研究正戊基过氧自由基自反应  

Study on Self-reaction of n-Pentyl Peroxy Radical by Vacuum Ultraviolet Photoionization Mass Spectrometry

作　　者：柳玲玉 马子吉 夏宇 林晓晓 张为俊 LIU Ling-Yu;MA Zi-Ji;XIA Yu;LIN Xiao-Xiao;ZHANG Wei-Jun(School of Environmental Science and Optoelectronic Technology,University of Science and Technology of China,Hefei 230026,China;Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;Science Island Branch,Graduate School,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学环境科学与光电技术学院,合肥230026 [2]中国科学院合肥物质科学研究院安徽光学精密机械研究所,合肥230031 [3]中国科学技术大学研究生院科学岛分院,合肥230026

出　　处：《分析化学》2024年第6期856-865,共10页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No.42075113)资助。

摘　　要：正戊基过氧自由基(C_(5)H_(11)O_(2))是正戊烷氧化过程中的关键中间体,在低NOx(NO和NO_(2))条件下,其自反应对大气自由基的链传播和终止具有重要的作用。采用微波放电快速流动管反应器,结合真空紫外光电离质谱仪在线检测自反应产物。结果表明,C_(5)H_(11)O_(2)自反应存在3个产物通道,对应的产物分别为烷氧自由基C_(5)H_(11)O、羰基化合物C_(5)H_(10)O和有机醇C_(5)H_(11)OH,以及二聚体产物C_(5)H_(11)OOC_(5)H_(11)。为了进一步确定产物的来源通道,开展了反应动力学研究,通过比较主要产物的实验结果与模拟计算结果,揭示了C_(5)H_(11)O_(2)自反应机理。本研究在线测量了C_(5)H_(11)O_(2)自反应形成的二聚体产物C_(5)H_(11)OOC_(5)H_(11),预测其产物通道分支比约为10%,并结合量子化学理论计算确定了其分子离子结构。The n-pentyl peroxy radical(C_(5)H_(11)O_(2))is a crucial intermediate in the oxidation process of n-pentane,playing an important role in the chain propagation and termination of atmospheric radicals under low NOx conditions.The products from the self-reaction of C_(5)H_(11)O_(2)were detected online by a microwave discharge fast-flow reactor combined with a vacuum ultraviolet photoionization mass spectrometry in this work.The results indicated three product channels in the self-reaction of C_(5)H_(11)O_(2),corresponding to alkoxyl radicals(C_(5)H_(11)O),carbonyl compounds(C_(5)H_(10)O)and organic alcohol(C_(5)H_(11)OH),as well as dimeric products(C_(5)H_(11)OOC_(5)H_(11)).Further research was conducted to determine the original channels of the products through reaction kinetics experiments,revealing the self-reaction mechanism of C_(5)H_(11)O_(2)by comparing the experimental and the simulated results of the main products.The dimeric product C_(5)H_(11)OOC_(5)H_(11),formed in the self-reaction of C_(5)H_(11)O_(2),was measured online for the first time,predicting its channel branching ratio to be approximately 10%.The molecular and ionic structures of the product were determined with the help of quantum chemical theoretical calculations.

关 键 词：过氧自由基 自反应 真空紫外光电离 动力学实验 二聚体产物 

分 类 号：X51[环境科学与工程—环境工程] O657.63[理学—分析化学]