Theoretical study on the formation mechanism of pre-intermediates for PXDD/Fs from 2-Bromophenol and 2-Chlorophenol precursors via radical/molecule reactions

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境化学与生态毒理学国家重点实验室

	Theoretical study on the formation mechanism of pre-intermediates for PXDD/Fs from 2-Bromophenol and 2-Chlorophenol precursors via radical/molecule reactions
	Fu, Jianjie; Pan, Wenxiao; Zhang, Aigian
刊名	ENVIRONMENTAL POLLUTION
	2017-09-01
卷号	225 期号:0 页码:439-449
关键词	Pxdd/fs Formation Mechanism Radical/molecule Reactions Dft Study
英文摘要	This study investigates reaction pathways for the formation of pre-PXDD/F intermediates via a radical/molecule mechanism. Thermodynamic and kinetic parameters for the combination reactions of 2-bromophenol (2-BP) and 2-chlorophenol (2-CP) precursors with key radical species including the phenoxy radicals, the phenyl radicals and the phenoxyl diradicals were calculated in detail. The couplings of phenoxy radicals with 2-B(C)P tend to produce pre-PXDD intermediates of halogenated o-phenoxyphenol. The combinations of phenyl and phenoxyl diradicals with 2-B(C)P produce two types of structures, i.e., dihydroxybiphenyl and o-phenoxyphenyl, which exclusively act as prestructures of PXDFs. These condensation reactions, especially those involving the phenyl C atom sites in phenyl and phenoxyl diradicals, are proven to be both thermodynamically and kinetically favorable and are nearly comparable with the corresponding steps involved in the radical/radical reactions. Most importantly, reactions of phenyl and phenoxyl diradicals with halogenated phenols solely lead to the formation of PXDFs, which to some extent provides a plausible explanation for the high PXDF-to-PXDD ratios in the real environment. Therefore, our study reveals the pivotal role of the radical/molecule mechanism in homogeneous gas-phase PXDD/F formation, especially in PXDF formation. The present results fill in a knowledge gap that has hitherto existed regarding dioxin formation and improve our understanding of PXDD/F formation characteristics in the environment. (C) 2017 Elsevier Ltd. All rights reserved.
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/39438]
专题	生态环境研究中心_环境化学与生态毒理学国家重点实验室
推荐引用方式 GB/T 7714	Fu, Jianjie,Pan, Wenxiao,Zhang, Aigian. Theoretical study on the formation mechanism of pre-intermediates for PXDD/Fs from 2-Bromophenol and 2-Chlorophenol precursors via radical/molecule reactions[J]. ENVIRONMENTAL POLLUTION,2017,225(0):439-449.
APA	Fu, Jianjie,Pan, Wenxiao,&Zhang, Aigian.(2017).Theoretical study on the formation mechanism of pre-intermediates for PXDD/Fs from 2-Bromophenol and 2-Chlorophenol precursors via radical/molecule reactions.ENVIRONMENTAL POLLUTION,225(0),439-449.
MLA	Fu, Jianjie,et al."Theoretical study on the formation mechanism of pre-intermediates for PXDD/Fs from 2-Bromophenol and 2-Chlorophenol precursors via radical/molecule reactions".ENVIRONMENTAL POLLUTION 225.0(2017):439-449.