Visible photooxidation of dibenzothiophenes sensitized by 2-(4-methoxyphenyl)-4, 6-diphenylpyrylium: An electron transfer mechanism without involvement of superoxide
文献类型：期刊论文
| 作者 | Che, YK; Ma, MH; Ji, HW; Zhao, JC; Zang, L |
| 刊名 | JOURNAL OF PHYSICAL CHEMISTRY B
 |
| 出版日期 | 2006-02-16 |
| 卷号 | 110期号:6页码:2942-2948 |
| ISSN号 | 1520-6106 |
| DOI | 10.1021/jp055261f |
| 英文摘要 | We report here on a new electron-transfer mechanism for visible-light photooxidation of sulfides in which no superoxide ion is involved. Visible-light irradiation of 2-(4-methoxyphenyl)-4, 6-diphenylpyrylium tetrafluoroborate (MOPDPP+BF4-) in an O-2-saturated acetonitrile solution containing dibenzothiophene (DBT) results in nearly 100% conversion to oxygenated products, DBT sulfoxide and sulfone. The photooxidation of DBT is initiated by a photoinduced electron-transfer process, where the excited MOPDPP+ traps an electron from the ground-state DBT to form MOPDPPcenter dot and DBT radical cation. Such a mechanism is consistent with the studies of laser flash photolysis, electron spin resonance, and fluorescence quenching of the irradiated system. The photogenerated DBT radical cation undergoes a coupling reaction with 0, to produce the intermediate responsible for the formation of the oxygenated products. The presence of 0, has no effect on the decay kinetics of the transient absorption of MOPDPPcenter dot, indicating that no redox reaction occurs between MOPDPPcenter dot and O-2, and thus no superoxide ion (O-2(center dot-)) is formed. Moreover, the ESR signal of MOPDPPcenter dot was significantly enhanced in the presence Of 02, consistent with the assumption that the photogenerated DBT radical cation couples with 0, to form the oxygen-adduct, which is subject to further reactions (Scheme 3) leading to the final oxygenated products. Similar results have been obtained when using 10-methylacridine hexafluorophosphate (AcrH(+)PF(6)(-), which has similar reduction potential in the ground state as MOPDPP+) as the sensitizer. This finding provides a possibility for the photooxidation of sulfides with dioxygen utilizing visible light (solar energy) and is also of significance in clarification of the reaction mechanism. |
| 语种 | 英语 |
| WOS记录号 | WOS:000235373400067 |
| 出版者 | AMER CHEMICAL SOC |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/58503]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Zhao, JC |
| 作者单位 | 1.Chinese Acad Sci, Key Lab Photochem, Ctr Mol Sci, Inst Chem, Beijing 100080, Peoples R China 2.So Illinois Univ, Dept Chem & Biochem, Carbondale, IL 62901 USA |
| 推荐引用方式 GB/T 7714 | Che, YK,Ma, MH,Ji, HW,et al. Visible photooxidation of dibenzothiophenes sensitized by 2-(4-methoxyphenyl)-4, 6-diphenylpyrylium: An electron transfer mechanism without involvement of superoxide[J]. JOURNAL OF PHYSICAL CHEMISTRY B,2006,110(6):2942-2948. |
| APA | Che, YK,Ma, MH,Ji, HW,Zhao, JC,&Zang, L.(2006).Visible photooxidation of dibenzothiophenes sensitized by 2-(4-methoxyphenyl)-4, 6-diphenylpyrylium: An electron transfer mechanism without involvement of superoxide.JOURNAL OF PHYSICAL CHEMISTRY B,110(6),2942-2948. |
| MLA | Che, YK,et al."Visible photooxidation of dibenzothiophenes sensitized by 2-(4-methoxyphenyl)-4, 6-diphenylpyrylium: An electron transfer mechanism without involvement of superoxide".JOURNAL OF PHYSICAL CHEMISTRY B 110.6(2006):2942-2948. |
入库方式： OAI收割
来源：化学研究所
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