Unveiling self-sensitized photodegradation pathways by DPT calculations: A case of sunscreen p-aminobenzoic acid
文献类型：期刊论文
| 作者 | Zhang, Siyu1; Chen, Jingwen2; Zhao, Qing1; Xie, Qing2; Wei, Xiaoxuan2 |
| 刊名 | CHEMOSPHERE
 |
| 出版日期 | 2016-11-01 |
| 卷号 | 163页码:227-233 |
| 关键词 | Self-sensitized photodegradation mechanism Singlet state oxygen p-aminobenzoic acid Density functional theory |
| 英文摘要 | Self-sensitized photodegradation has been observed for diverse aquatic organic pollutants. However, photodegradation pathways have not been clarified in, previous experimental studies. Here, we attempted to probe self-sensitized photodegradation pathways of organic pollutants employing both photolytic experiments and density functional theory calculations. By performing photolytic experiments, we found that singlet state oxygen (O-1(2)) play an essential role in photodegradation of a sunscreen p-aminobenzoic acid (PABA). PABA can photogenerate O-1(2) and react fast with O-1(2). We hypothesized that PABA underwent O-1(2) induced self-sensitized photodegradation. By calculating transition states, intermediates and reaction barriers, we found that O-1(2) can oxidize PABA through electrophilic attacks on the benzene ring to abstract one H atom of the amino group following a 1,3-addition mechanism or to induce decarboxylation. Either pathway produces a hydroperoxide. O-O bond cleavage of the hydro peroxides occurring at ground states or the lowest triplet excited states can produce phenoxyl radical precursors of 4-amino-3-hydroxybenzoic acid and 4-aminophenol, which are photodegradation products detected in experiments. Thus, a viable O-1(2) self-sensitized photodegradation mechanism was unveiled for PABA. (C) 2016 Elsevier Ltd. All rights reserved. |
| WOS标题词 | Science & Technology ; Life Sciences & Biomedicine |
| 类目[WOS] | Environmental Sciences |
| 研究领域[WOS] | Environmental Sciences & Ecology |
| 关键词[WOS] | SIMULATED SUNLIGHT IRRADIATION ; MOLECULAR-OXYGEN O-1(2) ; SINGLET OXYGEN ; AQUATIC PHOTOCHEMISTRY ; TRANSITION-STATES ; AQUEOUS-SOLUTION ; MECHANISMS ; KINETICS ; DEGRADATION ; PHOTOTRANSFORMATION |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000384776800026 |
| 源URL | [http://210.72.129.5/handle/321005/65916]  |
| 专题 | 沈阳应用生态研究所_沈阳应用生态研究所_期刊论文 |
| 作者单位 | 1.Chinese Acad Sci, Inst Appl Ecol, Key Lab Pollut Ecol & Environm Engn, Shenyang 110016, Peoples R China 2.Dalian Univ Technol, Sch Environm Sci & Technol, Key Lab Ind Ecol & Environm Engn MOE, Linggong Rd 2, Dalian 116024, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhang, Siyu,Chen, Jingwen,Zhao, Qing,et al. Unveiling self-sensitized photodegradation pathways by DPT calculations: A case of sunscreen p-aminobenzoic acid[J]. CHEMOSPHERE,2016,163:227-233. |
| APA | Zhang, Siyu,Chen, Jingwen,Zhao, Qing,Xie, Qing,&Wei, Xiaoxuan.(2016).Unveiling self-sensitized photodegradation pathways by DPT calculations: A case of sunscreen p-aminobenzoic acid.CHEMOSPHERE,163,227-233. |
| MLA | Zhang, Siyu,et al."Unveiling self-sensitized photodegradation pathways by DPT calculations: A case of sunscreen p-aminobenzoic acid".CHEMOSPHERE 163(2016):227-233. |
入库方式： OAI收割
来源：沈阳应用生态研究所
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