Role of Vibrational Dynamics on Excited-State Electronic Coherence in a Binuclear Platinum Complex
Role of Vibrational Dynamics on Excited-State Electronic Coherence in a Binuclear Platinum Complex
复制标题
振动动力学对双核铂配合物中激发态电子相干性的作用
DOI：
10.1021/acs.jpca.8b01352
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Li, Xiaosong
中科院分区：
文献类型：
--
作者：
Radler, Joseph J.;Lingerfelt, David B.;Castellano, Felix N.;Chen, Lin X.;Li, Xiaosong
激发电子态之间的长寿命量子相干性可以在化学系统中实现高效的能量和电荷传输过程。最近对双核铂配合物进行的泵浦探针实验发现了瞬态吸收各向异性信号的持续、周期性跳动，表明激发态相干寿命较长。我们之前对这些配合物的电子动力学的模拟表明，相干寿命对竞争性电子耦合之间的平衡很敏感。具有较短 Pt-Pt 距离的配合物在静态核的极限内没有经历明显的相移，这促使我们将核运动纳入我们的模拟中。这项工作使用混合量子经典动力学的 Ehrenfest 方法研究了叔丁基取代的络合物，以研究振动动力学对显示支持长相干寿命的络合物的作用。结果表明，在实验确定的系间交叉之前，激发态振动的包含会导致两态相干性快速崩溃。这进一步表明单重态激发态相干性可能不是长寿命三重态相干性的先决条件。
Long-lived quantum coherence between excited electronic states can enable highly efficient energy and charge transport processes in chemical systems. Recent pump–probe experiments on binuclear platinum complexes identified persistent, periodic beating of transient absorption anisotropy signals, indicating long excited-state coherence lifetimes. Our previous simulations of the electronic dynamics of these complexes indicate that coherence lifetimes are sensitive to the balance between competitive electronic couplings. The complexes with shorter Pt–Pt distances underwent no appreciable dephasing in the limit of static nuclei, motivating the inclusion of nuclear motion into our simulations. Thetert-butyl-substituted complex is studied in this work using the Ehrenfest method for mixed quantum–classical dynamics to investigate the role of vibrational dynamics on a complex shown to support long coherence lifetimes. Results indicate that the inclusion of excited-state vibrations drives a rapid collapse of the two-state coherence prior to the experimentally determined intersystem crossing. This further suggests singlet excited-state coherences may not be prerequisites for long-lived triplet coherences.