Study on ozonolysis of asymmetric alkenes with matrix isolation and FT-IR spectroscopy.
Study on ozonolysis of asymmetric alkenes with matrix isolation and FT-IR spectroscopy.
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DOI：
10.1016/j.chemosphere.2020.126413
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发表时间：
2020-03
期刊：
影响因子：
8.8
通讯作者：
Zhen Wang;Shengrui Tong;Meifang Chen;Bo Jing;Weiran Li;Yucong Guo;Maofa Ge;Sufan Wang
中科院分区：
文献类型：
--
作者：
Zhen Wang;Shengrui Tong;Meifang Chen;Bo Jing;Weiran Li;Yucong Guo;Maofa Ge;Sufan Wang
O3和烯烃是大气中SOA形成的重要反应物。烯烃臭氧化反应的中间体和反应机理是大气化学研究的重要课题。采用低温基质分离技术对2-甲基-1-丁烯（2 M1 B）和2-甲基-2-丁烯（2 M2 B）臭氧化反应生成的初级臭氧化物（POZs）、Criegee中间体（CIs）和次级臭氧化物（SOZs）进行了分离。通过真空红外光谱和理论计算对实验结果进行了验证。结果表明，在不对称烯烃的臭氧化过程中，由于POZ的分解方式不同，生成了两种CI和两种以上的SOZ。（CH 3）2COO和CH 3CH 2C（CH 3）OO的O-O伸缩振动的红外吸收峰分别为889 cm− 1和913 cm−1。采用合并喷射法发现，2 M1 B臭氧化过程中产生大量甲醛，2 M2 B臭氧化过程中产生乙二醛和甲基乙二醛。我们的研究结果突出了不对称烯烃臭氧化反应在产生氯离子的重要性，进一步提高了对烯烃臭氧化生成氯离子的理解。
O3and alkenes are important reactants in the formation of SOA in the atmosphere. The intermediates and reaction mechanism of ozonation of alkene is an important topic in atmospheric chemistry. In this study, the low-temperature matrix isolation was used to capture the intermediates such as Primary ozonides (POZs), Criegee Intermediates (CIs), and Secondary ozonides (SOZs) generated from ozonation of 2-methyl-1-butene (2M1B) and 2-methyl-2-butene (2M2B). The results have been identified by the vacuum infrared spectroscopy and theoretical calculation. Our results show that during the ozonation of asymmetric alkenes, two kinds of CIs and more than two kinds of SOZs were generated due to the different decomposition modes of POZs. The infrared absorption peaks of (CH3)2COO and CH3CH2C(CH3)OO for O–O telescopic vibration was determined to be 889 cm−1and 913 cm−1, respectively. Using the merged jet method, it was found that a large amount of HCHO was produced during the ozonation of 2M1B, and glyoxal and methylglyoxal were produced in the ozonation of 2M2B. Our findings highlight the importance of asymmetric alkene ozonolysis reactions in producing CIs, further improving the understanding of the generation of CIs from ozonation of alkenes.