Study of the Synchrotron Photoionization Oxidation of 2-Methylfuran Initiated by O(3P) under Low-Temperature Conditions at 550 and 650 K
Study of the Synchrotron Photoionization Oxidation of 2-Methylfuran Initiated by O(3P) under Low-Temperature Conditions at 550 and 650 K
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DOI：
10.1021/acs.jpca.7b05561
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发表时间：
2017-09-21
影响因子：
2.9
通讯作者：
Meloni, Giovanni
中科院分区：
文献类型：
--
作者：
Fathi, Yasmin;Meloni, Giovanni
利用劳伦斯伯克利国家实验室先进光源的真空紫外同步辐射，研究了O-(P-3)引发的2-甲基呋喃（2-MF）氧化反应。用多路光电离质谱法在550和650 K下研究了反应物质。在这个反应中，氧加成途径是有利的，形成4个三重态二自由基，经过系统间交叉成为单线态环氧化物，从而形成m/z 30（甲醛）、42（丙烯）、54（1-丁烯、1,3-丁二烯和2-丁烯）和70（2-丁烯、甲基乙烯酮和3-丁烯）的产物。获得了每个主反应种的质荷比、光电离谱和绝热电离能，并用于表征它们的特性。此外，通过电子结构计算，对氧化过程中产生的不同物质的势能表面扫描进行了检查，以进一步验证初级化学的发生。在两种温度下计算了初级产物形成的分支分数，在550 K和650 K下分别占81.0 +/- 21.4%和92.1 +/- 25.5%。
The O-(P-3)-initiated oxidation of 2-methylfuran (2-MF) was investigated using vacuum-ultraviolet synchrotron radiation from the Advanced Light Source at Lawrence Berkeley National Laboratory. Reaction species were studied by multiplexed photoionization mass spectrometry at 550 and 650 K. The oxygen addition pathway is favored in this reaction, forming four triplet diradicals that undergo intersystem crossing into singlet epoxide species that lead to the formation of products at m/z 30 (formaldehyde), 42 (propene), 54 (1-butyne, 1,3-butadiene, and 2-butyne), and 70 (2-butenal, methyl vinyl ketone, and 3-butenal). Mass-to-charge ratios, photoionization spectra, and adiabatic ionization energies for each primary reaction species were obtained and used to characterize their identities. In addition, by means of electronic structure calculations, potential energy surface scans of the different species produced throughout the oxidation were examined to further validate the primary chemistry occurring. Branching fractions for the formation of the primary products were calculated at the two temperatures and contribute 81.0 +/- 21.4% at 550 K and 92.1 +/- 25.5% at 650 K.