ICCAS OpenIR
Photogeneration of singlet oxygen (O-1(2)) and free radicals (Sen(center dot-),O-2(center dot)- by tetra-brominated hypocrellin B derivative
Ma, JH; Jiang, LJ
2001
Source PublicationFREE RADICAL RESEARCH
ISSN1071-5762
Volume35Issue:6Pages:767-777
AbstractTo improve photodynamic activity of the parent hypocrellin B (HB), a tetra-brominated HB derivative (compound 1) was synthesized in high yield. Compared with HB, compound I has enhanced red absorption and high molar extinction coefficients. The photodynamic action of compound 1, especially the generation mechanism and efficiencies of active species (Sens(-), O-2(-) and O-1(2)) were studied using electron paramagnetic resonance (EPR) and spectrophotometric methods. In the deoxygenated DMSO solution of compound 1, the semiquinone anion radical of compound 1 is photogenerated via the self-electron transfer between the excited and ground state species. The presence of electron donor significantly promotes the reduction of compound 1. When oxygen is present, superoxide anion radical (O-2(-)) is formed via the electron transfer from Sens(-) the ground state molecular oxygen. The efficiencies of Sens(-) and O-2(-) generation by compound 1 are about three and two times as much as that of HB, respectively. Singlet oxygen (O-1(2)) can be produced via the energy transfer from triplet compound 1 to ground state oxygen molecules. The quantum yield of singlet oxygen (O-1(2)) is 0.54 in CHCl3 similar to that of HB. Furthermore, it was found that the accumulation of Sens- would replace that of O-2(-) or O-1(2) with the depletion of oxygen in the sealed system.
KeywordTetra-brominated Hypocrellin b Semiquinone Anion Radical Superoxide Anion Radical Singlet Oxygen Electron Paramagnetic Resonance
Indexed BySCI
Language英语
WOS IDWOS:000174639900012
PublisherTAYLOR & FRANCIS LTD
Citation statistics
Cited Times:13[WOS]   [WOS Record]     [Related Records in WOS]
Document Type期刊论文
Identifierhttp://ir.iccas.ac.cn/handle/121111/77848
Collection中国科学院化学研究所
Corresponding AuthorJiang, LJ
AffiliationChinese Acad Sci, Inst Chem, Ctr Mol Sci, Beijing 100080, Peoples R China
Recommended Citation
GB/T 7714
Ma, JH,Jiang, LJ. Photogeneration of singlet oxygen (O-1(2)) and free radicals (Sen(center dot-),O-2(center dot)- by tetra-brominated hypocrellin B derivative[J]. FREE RADICAL RESEARCH,2001,35(6):767-777.
APA Ma, JH,&Jiang, LJ.(2001).Photogeneration of singlet oxygen (O-1(2)) and free radicals (Sen(center dot-),O-2(center dot)- by tetra-brominated hypocrellin B derivative.FREE RADICAL RESEARCH,35(6),767-777.
MLA Ma, JH,et al."Photogeneration of singlet oxygen (O-1(2)) and free radicals (Sen(center dot-),O-2(center dot)- by tetra-brominated hypocrellin B derivative".FREE RADICAL RESEARCH 35.6(2001):767-777.
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