Photoinduced Electron Transfer in an Oligodeoxynucleotide Duplex: Observation of the Electron-Transfer Intermediate
作者:Mark T. Tierney、Milan Sykora、Shoeb I. Khan、Mark W. Grinstaff
DOI:10.1021/jp001539m
日期:2000.8.1
Kinetics of a photoinduced electron-transfer reaction between phenothiazine (PTZ) and Ru(bpy)2(4-m-4‘-pa-bpy)2+ [bpy = 2,2‘-bipyridine and 4-m-4‘-pa-bpy = 4-methyl-4‘-carbonylpropargylamine] covalently bound to a DNA duplex is investigated by transient absorption spectroscopy. The electron donor, PTZ, is attached to the 5‘ terminal of one oligodeoxynucleotide strand, and the chromophore, Ru(bpy)2(4-m-4‘-pa-bpy)2+
吩噻嗪 (PTZ) 和 Ru(bpy)2(4-m-4'-pa-bpy)2+ [bpy = 2,2'-联吡啶和 4-m-4'- 之间的光诱导电子转移反应动力学pa-bpy = 4-methyl-4'-carbonylpropargylamine] 通过瞬态吸收光谱研究共价结合到 DNA 双链体上。电子供体 PTZ 连接到一条寡脱氧核苷酸链的 5' 末端,发色团 Ru(bpy)2(4-m-4'-pa-bpy)2+ 共价连接到互补链。供体 PTZ 和光激发受体 *Ru(bpy)2(4-m-4'-pa-bpy)2+ 之间发生电子转移,正向电子转移反应的产物 PTZ+• 为观测到的。反向电子转移反应的速率 (kb = 3.94 × 106 s-1; ΔG ∼ 2.0 eV) 是通过监测电子转移中间体 PTZ+• 的衰减来确定的,