Formation of Chlorotriophenoxy Radicals from Complete Series Reactions of Chlorotriophenols with H and OH Radicals.
Formation of Chlorotriophenoxy Radicals from Complete Series Reactions of Chlorotriophenols with H and OH Radicals.
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氯三苯酚与 H 和 OH 自由基的全系列反应形成氯三苯氧基自由基
DOI：
10.3390/ijms160818714
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发表时间：
2015-08-11
影响因子：
5.6
通讯作者：
Wang W
中科院分区：
文献类型：
--
作者：
Xu F;Shi X;Zhang Q;Wang W
氯代硫代苯氧基(CTPR)是多氯二苯并硫杂菲(PCDT/TAS)形成的关键中间体。本文用密度泛函理论(DFT)方法研究了19种氯硫酚(CTP)同系物与H和OH自由基的全系列反应生成CTPR的反应机理。势能面在MPWB1K/6-311+G(3df，2p)//MPWB1K/6-31+G(d，p)水平上建立。用正则变分过渡态(CVT)理论和小曲率隧道效应(SCT)计算了CTP在600-1200K温度范围内的速率常数。研究表明，CTP的结构参数、热数据和速率常数以及CTPR的形成势强烈地受CTP邻位氯取代的影响。与氯苯酚(CPS)生成氯苯氧基(CPRs)的研究比较清楚地表明，H从CTPS中提取苯硫氧基氢的效率高于H从CPS中提取苯氧基氢的效率，而OH从CTPS中提取苯氧基氢的影响小于OH从CPS中提取苯氧基氢的影响。CTPS与H的反应比CTPS与OH的反应更容易发生，这与CPS与H和OH的反应性比较相反。
The chlorothiophenoxy radicals (CTPRs) are key intermediate species in the formation of polychlorinated dibenzothiophenes/thianthrenes (PCDT/TAs). In this work, the formation of CTPRs from the complete series reactions of 19 chlorothiophenol (CTP) congeners with H and OH radicals were investigated theoretically by using the density functional theory (DFT) method. The profiles of the potential energy surface were constructed at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level. The rate constants were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) contribution at 600–1200 K. The present study indicates that the structural parameters, thermal data, and rate constants as well as the formation potential of CTPRs from CTPs are strongly dominated by the chlorine substitution at the ortho-position of CTPs. Comparison with the study of formation of chlorophenoxy radicals (CPRs) from chlorophenols (CPs) clearly shows that the thiophenoxyl-hydrogen abstraction from CTPs by H is more efficient than the phenoxyl-hydrogen abstraction from CPs by H, whereas the thiophenoxyl-hydrogen abstraction from CTPs by OH is less impactful than the phenoxyl-hydrogen abstraction from CPs by OH. Reactions of CTPs with H can occur more readily than that of CTPs with OH, which is opposite to the reactivity comparison of CPs with H and OH.