Mechanism for OH-initiated atmospheric oxidation of the organophosphorus insecticide phorate

作者：Dang, Juan; Ding, Lei; Sun, Xiaoyan; Zhang, Qingzhu^*; Wang, Wenxing

来源：Structural Chemistry, 2014, 25(1): 275-284.

DOI：10.1007/s11224-013-0287-0

• Phorate
• OH radicals
• Atmospheric oxidation
• Reaction mechanism
• Kinetic parameters

Phorate, an extremely hazardous organophosphorus insecticide, is still widely used in many countries and territories currently. It may be released in the atmosphere where it can undergo transport and chemical transformations. In this study, the reaction mechanism for the OH-initiated atmospheric oxidation of phorate was investigated. The geometrical parameters and vibrational frequencies of all the stationary points were calculated at the MPWB1K level with the 6-31G(d,p) basis set. Single-point energy calculations were carried out at the MPWB1K/6-311+G(3df,2p) level. Canonical variational transition-state theory with small curvature tunneling contribution was used to calculate the rate constants over the temperature range of 200-370 K. The Arrhenius formulas were fitted. The results indicate that the channel of the formation of phorate oxon resulting from OH addition to phorate, and H abstractions from the -CH2- portion of the -CH2CH3 group in phorate are energetically favorable. The main degradation products include phorate oxon, SO2.

• 出版日期2014-2
• 单位山东大学