Real-time observation of X-ray-induced intramolecular and interatomic electronic decay in CH2I2
Real-time observation of X-ray-induced intramolecular and interatomic electronic decay in CH2I2
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DOI：
10.1038/s41467-019-10060-z
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发表时间：
2019-05-16
影响因子：
16.6
通讯作者：
Ueda, Kiyoshi
中科院分区：
文献类型：
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作者：
Fukuzawa, Hironobu;Takanashi, Tsukasa;Ueda, Kiyoshi
X射线自由电子激光器（XFEL）的日益普及促进了单目标结构测定和结构动态实时跟踪的发展。解开与XFEL脉冲相互作用引发的分子级反应是开发此类应用的基本步骤。在这里，我们报告的实时观测XFEL诱导的电子衰变通过短寿命的瞬态电子状态的二碘甲烷分子，使用飞秒近红外探测激光。我们确定的瞬态填充在XFEL诱导俄歇级联的寿命，并发现，多电荷碘离子是从短寿命（类似于20 fs）的瞬态发出，而单电荷的起源于显着较长的寿命状态（类似于100 fs）。我们确定了这些不同的时间尺度背后的机制：相反，短暂的瞬态放松分子俄歇衰变，长寿命的衰变由两个碘原子之间的原子间库仑衰变，在分子碎片。
The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development of single-object structural determination and of structural dynamics tracking in realtime. Disentangling the molecular-level reactions triggered by the interaction with an XFEL pulse is a fundamental step towards developing such applications. Here we report real-time observations of XFEL-induced electronic decay via short-lived transient electronic states in the diiodomethane molecule, using a femtosecond near-infrared probe laser. We determine the lifetimes of the transient states populated during the XFEL-induced Auger cascades and find that multiply charged iodine ions are issued from short-lived (similar to 20 fs) transient states, whereas the singly charged ones originate from significantly longer-lived states (similar to 100 fs). We identify the mechanisms behind these different time scales: contrary to the short-lived transient states which relax by molecular Auger decay, the long-lived ones decay by an interatomic Coulombic decay between two iodine atoms, during the molecular fragmentation.