Livshits Ester, Luzon Itamar, Gope Krishnendu, Baer Roi, Strasser Daniel
Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
Fritz Haber Center for Molecular Dynamics and the Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
Commun Chem. 2020 Apr 21;3(1):49. doi: 10.1038/s42004-020-0294-1.
The time scales and formation mechanisms of tri-hydrogen cation products in organic molecule ionization processes are poorly understood, despite their cardinal role in the chemistry of the interstellar medium and in other chemical systems. Using an ultrafast extreme-ultraviolet pump and time-resolved near-IR probe, combined with high-level ab initio molecular dynamics calculations, here we report unambiguously that H formation in double-ionization of methanol occurs on a sub 100 fs time scale, settling previous conflicting findings of strong-field Coulomb explosion experiments. Our combined experimental-computational studies suggest that ultrafast competition, between proton-transfer and long-range electron-transfer processes, determines whether the roaming neutral H dynamics on the dication result in [Formula: see text] or [Formula: see text] fragments respectively.
尽管三氢阳离子产物在星际介质化学和其他化学系统中起着关键作用，但其在有机分子电离过程中的时间尺度和形成机制仍知之甚少。我们使用超快极紫外泵浦和时间分辨近红外探测技术，并结合高水平的从头算分子动力学计算，明确报告甲醇双电离过程中H的形成发生在亚100飞秒的时间尺度上，解决了此前强场库仑爆炸实验中相互矛盾的结果。我们的实验与计算相结合的研究表明，质子转移和远程电子转移过程之间的超快竞争决定了双离子上漫游中性H的动力学过程分别产生[公式：见原文]还是[公式：见原文]碎片。
