Stamm Jacob, Priyadarsini Swati S, Sandhu Shawn, Chakraborty Arnab, Shen Jun, Kwon Sung, Sandhu Jesse, Wicka Clayton, Mehmood Arshad, Levine Benjamin G, Piecuch Piotr, Dantus Marcos
Department of Chemistry, Michigan State University, East Lansing, Michigan, USA.
Department of Chemistry, Stony Brook University, Stony Brook, New York, USA.
Nat Commun. 2025 Jan 6;16(1):410. doi: 10.1038/s41467-024-55065-5.
The formation of following the double ionization of small organic compounds via a roaming mechanism, which involves the generation of H and subsequent proton abstraction, has recently garnered significant attention. Nonetheless, a cohesive model explaining trends in the yield of characterizing these unimolecular reactions is yet to be established. We report yield and femtosecond time-resolved measurements following the strong-field double ionization of CHX molecules, where X = OD, Cl, NCS, CN, SCN, and I. These measurements, combined with double-ionization-potential equation-of-motion coupled-cluster ab initio calculations used to determine the geometries and energetics of CHX dications, are employed to identify the key factors governing the formation of in certain doubly ionized CHX species and its absence in others. We also carry out ab initio molecular dynamics simulations to obtain detailed microscopic insights into the mechanism, yields, and timescales of production. We find that the excess relaxation energy released after double ionization of CHX molecules combined with substantial geometrical distortion that favors H formation prior to proton abstraction boost the generation of . Our study provides useful guidelines for examining alternative sources of in the universe.
通过漫游机制使小有机化合物发生双电离后形成[具体物质未明确，可根据上下文推测为某种特定产物]，该机制涉及氢的生成及随后的质子提取，最近受到了广泛关注。然而，尚未建立一个连贯的模型来解释表征这些单分子反应的[具体物质]产率趋势。我们报告了CHX分子（其中X = OD、Cl、NCS、CN、SCN和I）在强场双电离后的产率和飞秒时间分辨测量结果。这些测量结果，结合用于确定CHX双阳离子的几何结构和能量学的双电离势运动方程耦合簇从头算计算，被用于识别在某些双电离CHX物种中控制[具体物质]形成的关键因素以及在其他物种中其不存在的原因。我们还进行了从头算分子动力学模拟，以获得对[具体物质]产生的机制、产率和时间尺度的详细微观见解。我们发现，CHX分子双电离后释放的多余弛豫能量，加上在质子提取之前有利于氢形成的大量几何畸变，促进了[具体物质]的生成。我们的研究为研究宇宙中[具体物质]的替代来源提供了有用的指导。
