H-Atom Transfer Reaction of Photoinduced Excited Triplet Duroquinone with Tryptophan and Tyrosine in Acetonitrile-Water and Ethylene Glycol-Water Homogeneous Solutions  

乙腈-水和乙二醇-水均相溶液中光诱导杜醌激发三重态与色氨酸、酪氨酸的氢原子转移反应

作　　者：Cheng Yang Mei-rou Zhu Xian-ling Gong Ai-ving Gao Xin-sheng Xu 杨程;朱媚柔;龚现玲;高爱英;许新胜(安徽师范大学物理与电子信息学院,芜湖241000;安徽师范大学光电材料科学与技术安徽省重点实验室,芜湖241000)

机构地区：[1]School of Physics and Electronic Information,Anhui Normal University,Wuhu 241000,China [2]Anhui Province Key Laboratory of Optoelectric Materials Science and Technology,Anhui NormalUniversity,Wuhu 241000,China

出　　处：《Chinese Journal of Chemical Physics》2021年第3期256-262,I0047,共8页化学物理学报（英文）

基　　金：supported by the National Natural Science Foundation of China (No.21673003);the National Major Scientific Instrument and Equipment Development Project (No.21927814)。

摘　　要：Laser flash photolysis was used to investigate the photoinduced reactions of excited triplet bioquinone molecule duroquinone(DQ)with tryptophan(Trp)and tyrosine(Tyr)in acetonitrile-water(Me CN-H_(2)O)and ethylene glycol-water(EG-H_(2)O)solutions.The reaction mechanisms were analyzed and the reaction rate constants were measured based on Stern-Volmer equation.The H-atom transfer reaction from Trp(Tyr)to ^(3)DQ^(*)is dominant after the formation of^(3)DQ^(*)during the laser photolysis.For DQ and Trp in MeCN-H_(2)O and EG-H_(2)O solutions,^(3)DQ^(*)captures H-atom from Trp to generate duroquinone neutral radical DQH^(·),carboncentered tryptophan neutral radical Trp^(·)/NH and nitrogen-centered tryptophan neutral radical Trp/N^(·).For DQ and Tyr in Me CN-H_(2)O and EG-H_(2)O solutions,^(3)DQ^(*)captures H-atom from Tyr to generate duroquinone neutral radical DQH^(·) and tyrosine neutral radical Tyr/O^(·).The H-atom transfer reaction rate constant of^(3)DQ^(*)with Trp(Tyr)is on the level of 109 L·mol^(-1)·s^(-1),nearly controlled by diffusion.The reaction rate constant of^(3)DQ^(*)with Trp(Tyr)in Me CN/H_(2)O solution is larger than that in EG/H2O solution,which agrees with Stokes-Einstein relationship qualitatively.

关 键 词：Photosensitive damage TRYPTOPHAN TYROSINE Laser flash photolysis Duroquinone 

分 类 号：O643.11[理学—物理化学]