Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Important role of reaction field in photodegradation of deca-bromodiphenyl ether
T2 - theoretical and experimental investigations of solvent effects
AU - Xie, Qing
AU - Chen, Jingwen
AU - Shao, Jianping
AU - Chen, Chang'er
AU - Zhao, Hongxia
AU - Hao, Ce
PY - 2009/9
Y1 - 2009/9
N2 - Photolysis of deca-bromodiphenyl ether (BDE-209) was investigated in tetrahydrofuran, dichloromethane, isopropanol, acetone, ethanol, methanol, acetonitrile and dimethylsulfoxide. Noticeable differences of the photolytic rates and quantum yields were found in the diverse solvents. Different to the previous deductions, hydrogen donating efficiency and electron donating efficiency of solvents were not the decisive factors for the photolytic rate in this study, which was proved by the fast photolysis of BDE-209 in CCl(4), a solvent without hydrogen and difficult to donate electrons. Besides hydrogen addition process, intermolecular polymerization might occur during the photolysis. Density functional theory (DFT) calculation was performed to understand the molecular properties of BDE-209 in different solvents. The lowest singlet vertical excitation energy (E(ex)) and the average formal charge on Br (q(Br)(+)) of BDE-209, reflecting the difficulty for the excitation of BDE-209 and for the departing of Br atom, respectively, were changed by the reaction fields formed by the different solvents. E(ex) and q(Br)(+) linearly correlated with the photolytic activity (log k). This study is helpful to better understand the photolytic behavior of BDE-209 in different media. (C) 2009 Elsevier Ltd. All rights reserved.
AB - Photolysis of deca-bromodiphenyl ether (BDE-209) was investigated in tetrahydrofuran, dichloromethane, isopropanol, acetone, ethanol, methanol, acetonitrile and dimethylsulfoxide. Noticeable differences of the photolytic rates and quantum yields were found in the diverse solvents. Different to the previous deductions, hydrogen donating efficiency and electron donating efficiency of solvents were not the decisive factors for the photolytic rate in this study, which was proved by the fast photolysis of BDE-209 in CCl(4), a solvent without hydrogen and difficult to donate electrons. Besides hydrogen addition process, intermolecular polymerization might occur during the photolysis. Density functional theory (DFT) calculation was performed to understand the molecular properties of BDE-209 in different solvents. The lowest singlet vertical excitation energy (E(ex)) and the average formal charge on Br (q(Br)(+)) of BDE-209, reflecting the difficulty for the excitation of BDE-209 and for the departing of Br atom, respectively, were changed by the reaction fields formed by the different solvents. E(ex) and q(Br)(+) linearly correlated with the photolytic activity (log k). This study is helpful to better understand the photolytic behavior of BDE-209 in different media. (C) 2009 Elsevier Ltd. All rights reserved.
KW - BDE-209
KW - Photolysis
KW - Solvent effect
KW - Reaction field
KW - POLYBROMINATED DIPHENYL ETHERS
KW - DECABROMODIPHENYL ETHER
KW - ENERGY RELATIONSHIPS
KW - NATURAL SUNLIGHT
KW - WATER
KW - DEBROMINATION
KW - PHOTOLYSIS
KW - SEDIMENTS
KW - PBDES
KW - PARTITION
U2 - 10.1016/j.chemosphere.2009.06.054
DO - 10.1016/j.chemosphere.2009.06.054
M3 - Journal article
VL - 76
SP - 1486
EP - 1490
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
IS - 11
ER -