• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Dynamics Simulations with Spin-Flip Time-Dependent Density Functional Theory: Photoisomerization and Photocyclization Mechanisms of cis-Stilbene in pi pi* States
【24h】

Dynamics Simulations with Spin-Flip Time-Dependent Density Functional Theory: Photoisomerization and Photocyclization Mechanisms of cis-Stilbene in pi pi* States

机译：自旋翻转时变密度泛函理论的动力学模拟：π-π*态顺式-Stilbene的光致异构化和光环化机理

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

On-the-fly dynamics simulations were carried out using spin-flip time dependent density functional theory (SF-TDDFT) to examine the photoisomerization and photocyclization mechanisms of cis-stilbene following excitation to the pi pi* state. A state tracking method was devised to follow the target state among nearly degenerate electronic states during the dynamics simulations. The steepest descent path from the Franck-Condon structure of cis-stilbene in the pi pi* state is shown to reach the S-1-minimum of 4,4-dihydrophenanthrene (DHP) via a cis-stilbene-like structure (referred to as (S-1)(cis-min)) on a very flat region of the S1-potential energy surface. From the dynamics simulations, the branching ratio of the photoisomerization is calculated as trans:DHP = 35:13, in very good agreement with the experimental data, trans:DHP = 35:10. The discrepancy between the steepest descent pathway and the significant trans-stilbene presence in the branching ratio observed experimentally and herein computationally is clarified from an analysis of geometrical features along the reaction pathway, as well as the low barrier of 0.1 eV for the pathway from (S-1)cis-min to the twisted pyramidal structure on the S-1-potential energy surface. It is concluded that pi pi*-excited cis-stilbene propagates primarily toward the twisted structural region due to dynamic effects, with partial branching to the DHP structural region via the flat-surface region around (S-1)(cis-min).
机译：使用自旋翻转时间相关的密度泛函理论（SF-TDDFT）进行了动态动力学模拟，以研究激发到pi pi *状态后顺二苯乙烯的光致异构化和光环化机理。设计了一种状态跟踪方法，以在动力学仿真期间跟踪几乎退化的电子状态中的目标状态。从pi pi *态的顺式-sti的弗兰克-康登结构的最陡下降路径显示为通过类似顺式-sti的结构到达S-1最小的4,4-二氢菲（DHP）（称为在S1势能面的非常平坦的区域上表示为（S-1）（顺式最小）。从动力学模拟，光异构化的支化比计算为trans：DHP = 35:13，与实验数据trans：DHP = 35:10非常吻合。通过分析沿反应路径的几何特征以及从（）到该路径的0.1 eV的低势垒，可以清楚地看出实验中和此处通过计算观察到的最陡下降路径与明显的反式二苯乙烯存在的分支比之间的差异。 S-1）顺式最小化至S-1势能表面上的扭曲金字塔结构。结论是，由于动态效应，pi pi *激发的顺二苯乙烯主要向扭曲的结构区域传播，并通过（S-1）（cis-min）附近的平坦区域部分分支到DHP结构区域。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号