Quantum dynamics study of the competing ultrafast intersystem crossing and internal conversion in the "channel 3" region of benzene.
Quantum dynamics study of the competing ultrafast intersystem crossing and internal conversion in the "channel 3" region of benzene.
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DOI：
10.1063/1.4767054
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发表时间：
2012-11
期刊：
影响因子：
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通讯作者：
T. Penfold;R. Spesyvtsev;O. M. Kirkby;R. Minns;D. Parker;H. Fielding;G. Worth
中科院分区：
文献类型：
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作者：
T. Penfold;R. Spesyvtsev;O. M. Kirkby;R. Minns;D. Parker;H. Fielding;G. Worth
时间分辨光电子能谱可以获得飞秒时间尺度上化学过程动力学的详细信息。从这些详细的实验中得到的信号通常很难分析，因此理论计算在提供支持方面很重要。在本文中，我们继续研究苯激发进入“通道3”区域后光物理和光化学中的竞争途径[R。S. Minns，D. S. N.帕克，T。J. Penfold，G. A. Worth和H. H. Fielding，Phys.Chem.Chem.Phys.12，15607（2010）]，其中先前示出了计算的细节，建立在振动耦合哈密顿量[T. J. Penfold和G. A. Worth，J.Chem.Phys.131，064303（2009）]以包括三重歧管。还提出了新的实验数据表明，振荡信号是由于一个热带激励。实验结果表明，信号分别来自势面的三个区域，即三个开放通道，模拟结果表明，在激发到S（1）的振动激发态后，波包不仅穿过前富维类圆锥交叉回到单重基态，而且还经历了超快的系间跃迁到低三重态。然而，该模型是不够详细的捕捉由于热带的振荡信号的全部细节。
Time-resolved photoelectron spectroscopy can obtain detailed information about the dynamics of a chemical process on the femtosecond timescale. The resulting signal from such detailed experiments is often difficult to analyze and therefore theoretical calculations are important in providing support. In this paper we continue our work on the competing pathways in the photophysics and photochemistry of benzene after excitation into the "channel 3" region [R. S. Minns, D. S. N. Parker, T. J. Penfold, G. A. Worth, and H. H. Fielding, Phys. Chem. Chem. Phys. 12, 15607 (2010)] with details of the calculations shown previously, building on a vibronic coupling Hamiltonian [T. J. Penfold and G. A. Worth, J. Chem. Phys. 131, 064303 (2009)] to include the triplet manifold. New experimental data are also presented suggesting that an oscillatory signal is due to a hot band excitation. The experiments show that signals are obtained from three regions of the potential surfaces, three open channels, which are assigned with the help of simulations showing that following excitation into vibrationally excited-states of S(1) the wavepacket not only crosses through the prefulvenoid conical intersection back to the singlet ground state, but also undergoes ultrafast intersystem crossing to low lying triplet states. The model is, however, not detailed enough to capture the full details of the oscillatory signal due to the hot band.