Wang XiaoPeng,Tong ShengRui,Ge MaoFa,Wang WeiGang,Wang DianXun
The electronic structures of six mono-terpenoids and two of their oxygenated derivatives were studied by He I photoelectron spectroscopy (PES). The observed bands were interpreted on the basis of empirical arguments and theoretical calculations. The first vertical ionization potentials for β -pinene, α -terpinene, terpinolene, γ -terpinene, limonene, myrcene, citral, and terpinene-4-ol were determined to be 8.73, 7.57, 8.26, 8.30, 8.53, 8.68, 8.71, and 8.77 eV, respectively. Most of these values have not been determined by PES before. The correlations of the first vertical ionization potentials of these compounds to the natural logarithms of rate constants for their reactions with the radicals OH, NO 3 , and O 3 were determined. The correlation coefficients for their reactions with OH, NO 3 , and O 3 were 0.97, 0.91, and 0.95, respectively. This method is a powerful technique for predicting the rate constants for the atmospheric oxidation reactions of terpenoids.
Hu Lin,Tong Shengrui,Xu Yanyong,Zhang Hailiang,Yu Shanshan,Chen Meifang,Ge Maofa
Unsaturated ketones are typical oxygenated volatile organic compounds (OVOCs) with high reactivity, and are important precursors in air pollution. The sources of OVOCs are complex and include direct emissions and secondary oxidation formation of VOCs in the atmosphere. 2-Cyclohexen-1-one is a widespread substance, and is derived from the industrial catalytic oxidation of cyclohexene. In this paper, we investigated the rate constants of the chemical reactions of 2-cyclohexen-1-one with NO 3 radicals, which is (7.25±0.29)×10 −15 cm 3 ·molecule −1 ·s −1 at 298 K and under 1 atm (1 atm=101325Pa). It supplemented the kinetics of NO 3 radicals database, and revealed its effects in the nighttime atmosphere. In addition, the reaction products of 2-cyclohexen-1-one with NO 3 radicals were detected by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), which revealed a series of nitrate esters in the composition of the secondary organic aerosol (SOA), which may reduce atmospheric visibility. Finally, the possible pathways for the generation of the products were developed.