标题：Micro-mechanism and rate constants for OH-initiated degradation of methomyl in atmosphere
作者：Wu, Xiuchao; Sun, Xiaomin; Zhang, Chenxi; Gong, Chen; Hu, Jingtian
作者机构：[Wu, Xiuchao; Sun, Xiaomin; Zhang, Chenxi; Gong, Chen; Hu, Jingtian] Shandong Univ, Environm Res Inst, Jinan 250100, Peoples R China.
通讯作者地址：[Sun, XM]Shandong Univ, Environm Res Inst, Jinan 250100, Peoples R China.
关键词：Hydroxyl radical; Methomyl; Degradation mechanism; Rate constant
摘要：The atmospheric degradation reactions of the two isomers of methomyl (MTL) initiated by OH radical in the presence of O-2, NO and H2O have been investigated by density functional theory (DFT). The calculations were all carried out at MPWB1K level. The geometrical parameters and vibrational frequencies of stationary points were calculated with 6-31 + G (d, p) basis sets. Single-point energy calculations were performed with 6-311 + G (3df, 2p) basis sets. Profiles of the potential energy surface were constructed and all possible channels involved in the reactions were discussed. The rate constants of main elementary reactions were calculated over a temperature range of 200-400 K and mostly fitted to Arrhenius formulas. The atmospheric lifetimes of reaction species were discussed for the first time, which can be applied to the study on model simulation and management of hazardous materials. (c) 2014 Elsevier Ltd. All rights reserved.