Infrared Characterization of the Products and Rate Coefficient of the Reaction between Criegee Intermediate CH2OO and HNO3

Chen An Chung, Cho Wei Hsu, Yuan Pern Lee*

*此作品的通信作者

研究成果: Article同行評審

5 引文 斯高帕斯(Scopus)

摘要

The reactions of Criegee intermediates with HNO3are important in the polluted urban atmosphere because of their large rate coefficients and the significant concentration of HNO3. Employing a step-scan Fourier-transform spectrometer, we recorded infrared spectra of transient species and end products in the reaction CH2OO + HNO3upon irradiation of a flowing mixture of CH2I2/HNO3/N2/O2at 308 nm. Eight bands at 1686, 1426, 1348, 1294, 1052, 965, 891, and 825 cm-1were assigned to the absorption of the adduct nitrooxymethyl hydroperoxide (NMHP, NO3CH2OOH). Additional products from two dissociation channels were observed. Four bands at 1709, 1325, 1276, and 886 cm-1were assigned to H2C(O)ONO2(with coproduct OH), produced from the fission of the O-O bond of internally hot NMHP (NMHP*). Simultaneous detection of H2CO (1746 cm-1), NO2(1617 cm-1), and HO2(1392 and 1098 cm-1) indicated a direct cleavage of the N-OC and C-OO bonds of NMHP*. The relative yields of these three channels in pressure range 10-150 Torr were estimated. At 10 Torr, the absorption of internally excited HNO3near 885 and 1320 cm-1was also detected at an early stage of the reaction. We investigated also the rate coefficient of the reaction CH2OO + HNO3by probing the temporal profiles of the formation of NMHP and NO2under total pressures of 40 and 70 Torr at 298 K. The rate coefficient kHNO3= (2.4 ± 0.4) × 10-10cm3molecule-1s-1is less than half the only literature value, (5.4 ± 1.0) × 10-10cm3molecule-1s-1, reported by Foreman et al. (Angew. Chem. Int. Ed. 2016, 55, 10419-10422).

原文English
頁(從 - 到)5738-5750
頁數13
期刊Journal of Physical Chemistry A
126
發行號34
DOIs
出版狀態Published - 1 9月 2022

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