PMID- 25113193
OWN - NLM
STAT- MEDLINE
DCOM- 20141028
LR  - 20161125
IS  - 1879-1298 (Electronic)
IS  - 0045-6535 (Linking)
VI  - 114
DP  - 2014 Nov
TI  - Mechanisms of transformation of polychlorinated diphenyl ethers into 
      polychlorinated dibenzo-p-dioxins and dibenzofurans.
PG  - 129-35
LID - S0045-6535(14)00501-3 [pii]
LID - 10.1016/j.chemosphere.2014.04.027 [doi]
AB  - This study presents a detailed mechanistic account of the formation of 
      polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) 
      from polychlorinated diphenyl ethers (PCDEs). It applies the recently developed 
      meta hybrid M06-2X functional and deploys the 2,2'-dichlorodiphenylether 
      (2,2'-DCDE) molecule as a representative model compound for all PCDEs congeners. 
      We find that, exceedingly high activation enthalpies prevent the direct formation 
      of PCDFs from PCDEs via unimolecular elimination of HCl or Cl2. Rather, loss of 
      an ortho H/Cl atom initiates the transformation of PCDEs into PCDD/Fs. Subsequent 
      formation of PCDFs takes place through ring-closure reactions with modest 
      activation enthalpies, whereas the addition of a ground state oxygen molecule at 
      an apparent ortho radical site of a PCDE congener commences a complex, yet very 
      exothermic, mechanism leading to the formation of PCDDs. Splitting the ether 
      linkage through H/Cl addition at the pivot carbon constitutes a major source for 
      the formation of chlorophenoxy radicals and chlorobenzene molecules. Our kinetic 
      and mechanistic analyses demonstrate that, the degree and pattern of chlorination 
      of PCDEs display a negligible effect on the formation pathways of PCDD/Fs from 
      PCDEs.
CI  - Copyright (c) 2014 Elsevier Ltd. All rights reserved.
FAU - Altarawneh, Mohammednoor
AU  - Altarawneh M
AD  - School of Engineering and Information Technology, Murdoch University, 90 South 
      Street, Murdoch, WA 6150, Australia. Electronic address: 
      M.Altarawneh@murdoch.edu.au.
FAU - Dlugogorski, Bogdan Z
AU  - Dlugogorski BZ
AD  - School of Engineering and Information Technology, Murdoch University, 90 South 
      Street, Murdoch, WA 6150, Australia.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20140513
PL  - England
TA  - Chemosphere
JT  - Chemosphere
JID - 0320657
RN  - 0 (Benzofurans)
RN  - 0 (Dibenzofurans, Polychlorinated)
RN  - 0 (Environmental Pollutants)
RN  - 0 (Halogenated Diphenyl Ethers)
RN  - 0 (Polychlorinated Dibenzodioxins)
RN  - 0 (polychlorinated diphenyl ethers)
SB  - IM
MH  - Benzofurans/*chemistry
MH  - Dibenzofurans, Polychlorinated
MH  - Environmental Pollutants/*chemistry
MH  - Halogenated Diphenyl Ethers/*chemistry
MH  - Kinetics
MH  - Polychlorinated Dibenzodioxins/*analogs & derivatives/chemistry
MH  - Thermodynamics
OTO - NOTNLM
OT  - PCDD/Fs
OT  - PCDEs
OT  - Rate constants
OT  - Reaction mechanism
OT  - Trace pollutants
EDAT- 2014/08/13 06:00
MHDA- 2014/10/29 06:00
CRDT- 2014/08/13 06:00
PHST- 2013/12/03 00:00 [received]
PHST- 2014/03/28 00:00 [revised]
PHST- 2014/04/01 00:00 [accepted]
PHST- 2014/08/13 06:00 [entrez]
PHST- 2014/08/13 06:00 [pubmed]
PHST- 2014/10/29 06:00 [medline]
AID - S0045-6535(14)00501-3 [pii]
AID - 10.1016/j.chemosphere.2014.04.027 [doi]
PST - ppublish
SO  - Chemosphere. 2014 Nov;114:129-35. doi: 10.1016/j.chemosphere.2014.04.027. Epub 
      2014 May 13.