Mechanical and Kinetic Studies of the Formation of Polyhalogenated Dibenzo-p-dioxins from Hydroxylated Polybrominated Diphenyl Ethers and Chlorinated Derivatives

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• 作者：Haijie Cao ; Maoxia He ; Yanhui Sun ; Dandan Han
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：November 24, 2011
• 年：2011
• 卷：115
• 期：46
• 页码：13489-13497
• 全文大小：949K
• 年卷期：v.115,no.46(November 24, 2011)
• ISSN：1520-5215

文摘

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs),which may be generated from PBDEs, are more toxic than their matrix and have been detected in organisms. In this article, we have focused on the gas phase formation of polyhalogenated dibenzo-p-dioxins from several OH-PBDEs and their chlorinated derivatives. All of the geometries and frequencies are calculated at the MPWB1K/6-31+G(d,p) level of theory. The single point energy is obtained at the MPWB1K/6-311+G(3df,2p) level. Rate constants of each step have been calculated over a wide range of 200鈥?000 K using the canonical variational transition state (CVT) theory with small curvature tunneling (SCT) contribution. The rate equations are shown through Arrhenius formulas. The presence of chlorine atoms increases the reaction barrier for the formation of major products.