Mechanism of radical cation formation from the excited states of zeaxanthin and astaxanthin in chloroform
文献类型：期刊论文
| 作者 | Han, RM; Tian, YX; Wu, YS; Wang, P; Ai, XC; Zhang, JP; Skibsted, LH |
| 刊名 | PHOTOCHEMISTRY AND PHOTOBIOLOGY
 |
| 出版日期 | 2006-03-01 |
| 卷号 | 82期号:2页码:538-546 |
| ISSN号 | 0031-8655 |
| DOI | 10.1562/2005-09-30-RA-705 |
| 英文摘要 | The C-40 xanthophylls zeaxanthin and astaxanthin were confirmed to form radical cations, Car(.+), in the electron-accepting solvent chloroform by direct excitation using subpicosecond time-resolved absorption spectroscopy in combination with spectroelectrochemical determination of the near-infrared absorption of Car(.+). For the singlets, the S-2(1B(u)(+)) state and most likely the S-x(3A(g)(-)) state directly eject electrons to chloroform leading to the rapid formation of Car(.+) on a timescale of similar to 100 fs; the lowest-lying S-1(2A(g)(-)) state, however, remains inactive. Standard reduction potential for Car(.+) was determined by cyclic voltametry to have the value 0.63 V for zeaxanthin and 0.75 V for astaxanthin from which excited state potentials were calculated, which confirmed the reactivity toward radical cation formation. On the other hand, Car(.+) formation from the lowest triplet excited state T-1 populated through anthracene sensitization is mediated by a precursor suggested to be a solute-solvent complex detected with broad near-infrared absorption to the shorter wavelength side of the characteristic Car(.+) absorption. However, ground state carotenoids are able to react with a secondary solvent radical to yield Car(.+), a process occurring within 16 mu s for zeaxanthin and within 21 mu s for astaxanthin. Among the two xanthophylls together with lycopene and beta-carotene, all having 11 conjugated double bonds, zeaxanthin ranks with the highest reactivity in forming Car(.+) from either the S-2(1B(u)(+)) or the ground state. The effects of substituent groups on the reactivity are discussed. |
| 语种 | 英语 |
| WOS记录号 | WOS:000237048300029 |
| 出版者 | AMER SOC PHOTOBIOLOGY |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/59013]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Zhang, JP |
| 作者单位 | 1.Chinese Acad Sci, Inst Chem, State Key Lab Struct Chem Unstable & Stable Speci, Beijing, Peoples R China 2.Royal Vet & Agr Univ, Dept Food Sci, Frederiksberg C, Denmark |
| 推荐引用方式 GB/T 7714 | Han, RM,Tian, YX,Wu, YS,et al. Mechanism of radical cation formation from the excited states of zeaxanthin and astaxanthin in chloroform[J]. PHOTOCHEMISTRY AND PHOTOBIOLOGY,2006,82(2):538-546. |
| APA | Han, RM.,Tian, YX.,Wu, YS.,Wang, P.,Ai, XC.,...&Skibsted, LH.(2006).Mechanism of radical cation formation from the excited states of zeaxanthin and astaxanthin in chloroform.PHOTOCHEMISTRY AND PHOTOBIOLOGY,82(2),538-546. |
| MLA | Han, RM,et al."Mechanism of radical cation formation from the excited states of zeaxanthin and astaxanthin in chloroform".PHOTOCHEMISTRY AND PHOTOBIOLOGY 82.2(2006):538-546. |
入库方式： OAI收割
来源：化学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。