水性缓冲溶液中儿茶酚/邻醌氧化还原偶的超快光谱电化学研究

IF 3 4区 化学 Q3 CHEMISTRY, PHYSICAL
Sofia Goia, Gareth W. Richings, Matthew A. P. Turner, Jack M. Woolley, Joshua J. Tully, Samuel J. Cobb, Adam Burriss, Ben R. Robinson, Julie V. Macpherson, Vasilios G. Stavros
{"title":"水性缓冲溶液中儿茶酚/邻醌氧化还原偶的超快光谱电化学研究","authors":"Sofia Goia,&nbsp;Gareth W. Richings,&nbsp;Matthew A. P. Turner,&nbsp;Jack M. Woolley,&nbsp;Joshua J. Tully,&nbsp;Samuel J. Cobb,&nbsp;Adam Burriss,&nbsp;Ben R. Robinson,&nbsp;Julie V. Macpherson,&nbsp;Vasilios G. Stavros","doi":"10.1002/cptc.202300325","DOIUrl":null,"url":null,"abstract":"<p>Eumelanin is a natural pigment found in many organisms that provides photoprotection from harmful UV radiation. As a redox-active biopolymer, the structure of eumelanin is thought to contain different redox states of quinone, including catechol subunits. To further explore the excited state properties of eumelanin, we have investigated the catechol/o-quinone redox couple by spectroelectrochemical means, in a pH 7.4 aqueous buffered solution, and using a boron doped diamond mesh electrode. At pH 7.4, the two proton, two electron oxidation of catechol is promoted, which facilitates continuous formation of the unstable o-quinone product in solution. Ultrafast transient absorption (femtosecond to nanosecond) measurements of o-quinone species involve initial formation of an excited singlet state followed by triplet state formation within 24 ps. In contrast, catechol in aqueous buffer leads to formation of the semiquinone radical Δ<i>t</i>&gt;500 ps. Our results demonstrate the rich photochemistry of the catechol/o-quinone redox couple and provides further insight into the excited state processes of these key building blocks of eumelanin.</p>","PeriodicalId":10108,"journal":{"name":"ChemPhotoChem","volume":"8 9","pages":""},"PeriodicalIF":3.0000,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cptc.202300325","citationCount":"0","resultStr":"{\"title\":\"Ultrafast Spectroelectrochemistry of the Catechol/o-Quinone Redox Couple in Aqueous Buffer Solution\",\"authors\":\"Sofia Goia,&nbsp;Gareth W. Richings,&nbsp;Matthew A. P. Turner,&nbsp;Jack M. Woolley,&nbsp;Joshua J. Tully,&nbsp;Samuel J. Cobb,&nbsp;Adam Burriss,&nbsp;Ben R. Robinson,&nbsp;Julie V. Macpherson,&nbsp;Vasilios G. Stavros\",\"doi\":\"10.1002/cptc.202300325\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Eumelanin is a natural pigment found in many organisms that provides photoprotection from harmful UV radiation. As a redox-active biopolymer, the structure of eumelanin is thought to contain different redox states of quinone, including catechol subunits. To further explore the excited state properties of eumelanin, we have investigated the catechol/o-quinone redox couple by spectroelectrochemical means, in a pH 7.4 aqueous buffered solution, and using a boron doped diamond mesh electrode. At pH 7.4, the two proton, two electron oxidation of catechol is promoted, which facilitates continuous formation of the unstable o-quinone product in solution. Ultrafast transient absorption (femtosecond to nanosecond) measurements of o-quinone species involve initial formation of an excited singlet state followed by triplet state formation within 24 ps. In contrast, catechol in aqueous buffer leads to formation of the semiquinone radical Δ<i>t</i>&gt;500 ps. Our results demonstrate the rich photochemistry of the catechol/o-quinone redox couple and provides further insight into the excited state processes of these key building blocks of eumelanin.</p>\",\"PeriodicalId\":10108,\"journal\":{\"name\":\"ChemPhotoChem\",\"volume\":\"8 9\",\"pages\":\"\"},\"PeriodicalIF\":3.0000,\"publicationDate\":\"2024-04-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cptc.202300325\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"ChemPhotoChem\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/cptc.202300325\",\"RegionNum\":4,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"ChemPhotoChem","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/cptc.202300325","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0

摘要

乌黑色素是一种存在于许多生物体内的天然色素,它能抵御有害的紫外线辐射。作为一种具有氧化还原活性的生物聚合物,乌黑色素的结构被认为包含不同氧化还原态的醌,包括儿茶酚亚基。为了进一步探究乌梅素的激发态特性,我们在 pH 值为 7.4 的缓冲水溶液中使用掺硼金刚石网状电极,通过光谱电化学方法研究了儿茶酚/邻醌氧化还原对。在 pH 值为 7.4 时,促进了儿茶酚的双质子、双电子氧化作用,从而促进了溶液中不稳定的邻醌产物的持续形成。邻醌物种的超快瞬态吸收(飞秒到纳秒)测量涉及激发单线态的初始形成,随后在 24 ps 内形成三线态。相反,儿茶酚在水缓冲液中会形成半醌自由基 Δt > 500 ps。我们的研究结果证明了儿茶酚/邻醌氧化还原偶联物丰富的光化学性质,并进一步揭示了这些乌梅素关键结构单元的激发态过程。
本文章由计算机程序翻译,如有差异,请以英文原文为准。

Ultrafast Spectroelectrochemistry of the Catechol/o-Quinone Redox Couple in Aqueous Buffer Solution

Ultrafast Spectroelectrochemistry of the Catechol/o-Quinone Redox Couple in Aqueous Buffer Solution

Eumelanin is a natural pigment found in many organisms that provides photoprotection from harmful UV radiation. As a redox-active biopolymer, the structure of eumelanin is thought to contain different redox states of quinone, including catechol subunits. To further explore the excited state properties of eumelanin, we have investigated the catechol/o-quinone redox couple by spectroelectrochemical means, in a pH 7.4 aqueous buffered solution, and using a boron doped diamond mesh electrode. At pH 7.4, the two proton, two electron oxidation of catechol is promoted, which facilitates continuous formation of the unstable o-quinone product in solution. Ultrafast transient absorption (femtosecond to nanosecond) measurements of o-quinone species involve initial formation of an excited singlet state followed by triplet state formation within 24 ps. In contrast, catechol in aqueous buffer leads to formation of the semiquinone radical Δt>500 ps. Our results demonstrate the rich photochemistry of the catechol/o-quinone redox couple and provides further insight into the excited state processes of these key building blocks of eumelanin.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
ChemPhotoChem
ChemPhotoChem Chemistry-Physical and Theoretical Chemistry
CiteScore
5.80
自引率
5.40%
发文量
165
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信