Spin Chemical Control of Photoinduced Electron-Transfer Processes in Ruthenium(II)-Trisbipyridine-Based Supramolecular Triads: 2. The Effect of Oxygen, Sulfur, and Selenium as Heteroatom in the Azine Donor
作者:Matthew T. Rawls、Georg Kollmannsberger、C. Michael Elliott、Ulrich E. Steiner
DOI:10.1021/jp070221s
日期:2007.5.1
PXZ moiety, the heteroatom (X = O (oxygen), T (sulfur), and S (selenium)) is systematically varied to study spin-orbit coupling effects. On the nanosecond time scale, the first detectable photoinduced electron-transfer product after exciting the chromophore C2+ is the charge-separated (CS) state, D+-C2+-A+, where an electron of the PXZ moiety, D, has been transferred to the diquat moiety, A2+. The ma
对一系列共价连接的供体(PXZ)-Ru(联吡啶)3-受体(敌草快)复合物(D-C2 + -A2 +)进行了0到2.0 T磁场中的纳秒时间分辨吸收研究。在PXZ部分中,杂原子(X = O(氧),T(硫)和S(硒))被系统地改变以研究自旋轨道耦合效应。在纳秒级的时间尺度上,激发发色团C2 +后的第一个可检测到的光诱导电子转移产物为电荷分离(CS)状态D + -C2 + -A +,其中PXZ部分的电子D已转移至电子。敌草快部分,A2 +。假设通过建立具有纯三重态自旋相关性的CS态(3CS )。对于DCA-POZ和-PTZ(由于振动机制),磁场对T +/-(T0,S)弛豫速率常数kr的贡献约为4.5 x 10(5)s-1。 DCA-PSZ使用3.5 x 10(6)s-1(由于旋转机制)。仅从1CS自旋水平允许重组到单重态基态;反之亦然。即使对于DCA-PSZ,来自3CS的自旋禁止重组似乎也可以忽略