水溶液中的咯嗪发色团的光物理机理:QM/MM电子结构计算
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- 英文论文题名：QM/MM Study on Mechanistic Photophysics of Alloxazine Chromophore in Aqueous Solution
- 论文作者：解晓英 ; 常雪萍 ; 崔刚龙 ; 方维海
- 英文论文作者：Xiao-Ying Xie ; Xue-Ping Chang ; Ganglong Cui ; Wei-Hai Fang ; Laboratory of Theoretical and Computational Photochemistry ; Ministry of Education ; College of Chemistry ; Beijing Normal University
- 年：2016
- 作者机构：北京师范大学化学学院理论与计算光化学教育部重点实验室;
- 论文关键词：咯嗪 ; 无辐射弛豫 ; QM/MM
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十八分会：电子结构理论方法的发展与应用
- 语种：中文
- 分类号：O626
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十八分会 ; 电子结构理论方法的发展与应用
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：153k
- 原文格式：D
- 会议级别：全国
摘要
上世纪六十年代,在二甲基异咯嗪的质子转移反应中咯嗪首次被研究。实验上的研究主要集中在咯嗪与异咯嗪结构上的联系。~([1])与异咯嗪相比,咯嗪表现出了较低的荧光量子产率和较高的系间窜越量子产率。~([2])然而,咯嗪高效的无辐射弛豫路径仍然不明晰。我们应用QM/MM方法首次研究咯嗪在水溶液中的光物理性质。~([3])基于计算结果,最终我们提出了从最初的激发单重态到最低三重态的三条无辐射弛豫路径。根据EI-Sayed规则,我们认为其中两条路径发挥主要作用。~([4])
Alloxazines were first studied in the last sixties when the proton transfer reactions in lumichrome were discovered.Experimental studies in the last century were mainly driven by the fact that they are structurally related to isoalloxazines.Compared with isoalloxazine-the core chromophore of biologically important flavins, alloxazine exhibits much lower fluorescence quantum yield and larger intersystem crossing quantum yield.However, its efficient radiationless relaxation pathways are still elusive.We have employed the QM/MM method to explore for the first time the photophysics of alloxazine chromophore in aqueous solution.Finally, based on the present computational results, we have proposed three nonadiabatic relaxation pathways responsible for the formation of the lowest triplet state from the initially populated excited singlet state.According to the classical EI-Sayed rule, we suggest two of the three paths play a much more important role than the other one in the formation of the lowest triplet state.
Alloxazines were first studied in the last sixties when the proton transfer reactions in lumichrome were discovered.Experimental studies in the last century were mainly driven by the fact that they are structurally related to isoalloxazines.Compared with isoalloxazine-the core chromophore of biologically important flavins, alloxazine exhibits much lower fluorescence quantum yield and larger intersystem crossing quantum yield.However, its efficient radiationless relaxation pathways are still elusive.We have employed the QM/MM method to explore for the first time the photophysics of alloxazine chromophore in aqueous solution.Finally, based on the present computational results, we have proposed three nonadiabatic relaxation pathways responsible for the formation of the lowest triplet state from the initially populated excited singlet state.According to the classical EI-Sayed rule, we suggest two of the three paths play a much more important role than the other one in the formation of the lowest triplet state.
引文
[1]Grodowski,M.;Veyret,B.;Weiss,K.Photochem.Photobiol.1977,26:341.
[2]Sikorska,E.;Khmelinskii,I.;Worrall,D.;Koput,J.;Sikorska,M.J.Fluoresc.2004,14:57.
[3]Chang,X.-P.;Fang,Q.;Cui,G.J.Chem.Phys.2014,141:154311.
[4]Chang,X.-P.;Xie,X.-Y.;Cui,G.L.submitted.
[2]Sikorska,E.;Khmelinskii,I.;Worrall,D.;Koput,J.;Sikorska,M.J.Fluoresc.2004,14:57.
[3]Chang,X.-P.;Fang,Q.;Cui,G.J.Chem.Phys.2014,141:154311.
[4]Chang,X.-P.;Xie,X.-Y.;Cui,G.L.submitted.
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