We perform time-resolved ionization spectroscopy measurements of the excited state dynamics of CH₂I₂ and CH₂IBr following photoexcitation in the deep UV. The fragment ions produced by ionization with a vacuum-ultraviolet probe pulse are measured with velocity map imaging, and the momentum resolved yields are compared with trajectory surface hopping calculations of the measurement observable. Together with recent time-resolved photoelectron spectroscopy measurements of the same dynamics, these results provide a detailed picture of the coupled electronic and nuclear dynamics involved. Our measurements highlight the non-adiabatic coupling between electronic states, which leads to notable differences in the dissociation dynamics for the two molecules.

中文翻译：

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紫外泵VUV探针动量分辨光子光谱研究CH2I2和CH2IBr的激发态动力学

我们在深紫外线中进行光激发后，对CH ₂ I ₂和CH ₂ IBr的激发态动力学进行时间分辨电离光谱测量。用速度图成像测量由真空紫外探针脉冲电离产生的碎片离子，并将动量分辨的产率与可观察到的轨迹表面跳变计算进行比较。连同最近对相同动力学的时间分辨光电子能谱测量，这些结果提供了所涉及的电子和核动力学耦合的详细情况。我们的测量结果突出了电子态之间的非绝热耦合，这导致两个分子的解离动力学存在显着差异。