Mhatre Saurabh, Dube Zack, Staudte André, Gräfe Stefanie, Kübel Matthias
Institute of Optics and Quantum Electronics, Friedrich Schiller University, 07743, Jena, Germany.
Institute for Physical Chemistry, Friedrich Schiller University, 07743, Jena, Germany.
Sci Rep. 2025 Mar 18;15(1):9284. doi: 10.1038/s41598-025-93707-w.
When a chemical bond is broken, the molecular structure undergoes a transformation. An ideal experiment should probe the change in the electronic and nuclear structure simultaneously. Here, we present a method for the simultaneous time-resolved imaging of nuclear and electron dynamics by combining Coulomb explosion imaging with strong-field photoelectron momentum imaging. We study the dissociative photoionization of H and NO using time-resolved photoion-photoelectron coincidence spectroscopy. The measured delay-dependent kinetic energy release clearly reveals the ultrafast nuclear dynamics. The transient changes in the electronic structure of the dissociating [Formula: see text] molecular ion are studied by solving the three-dimensional Schrödinger equation in the fixed-nuclei approximation. A detailed comparison of the numerical results to those from a simple imaging model is conducted. The numerical results reflect the evolution in the electron density in the molecular ion as its bond is first stretched and then breaks apart. While these details remain unresolved in the H experiment, we demonstrate the sensitivity of the photoelectron signal to the site of electron localization following bond cleavage for the case of NO. Our work shows opportunities and challenges on the track towards capturing simple gas-phase chemical dynamics in complete molecular movies.
当化学键断裂时，分子结构会发生转变。一个理想的实验应该同时探测电子和核结构的变化。在此，我们提出一种通过将库仑爆炸成像与强场光电子动量成像相结合来同时对核动力学和电子动力学进行时间分辨成像的方法。我们使用时间分辨光离子 - 光电子符合光谱研究了H和NO的解离光离子化。测量得到的与延迟相关的动能释放清楚地揭示了超快核动力学。通过在固定核近似下求解三维薛定谔方程，研究了解离的[化学式：见原文]分子离子电子结构的瞬态变化。将数值结果与简单成像模型的结果进行了详细比较。数值结果反映了分子离子中电子密度在其键首先被拉伸然后断裂时的演化。虽然在H实验中这些细节仍未得到解决，但我们证明了对于NO的情况，光电子信号对键断裂后电子局域化位置的敏感性。我们的工作展示了在以完整分子电影形式捕捉简单气相化学动力学的道路上的机遇与挑战。
