Crane Stuart W, Ge Lingfeng, Cooper Graham A, Carwithen Ben P, Bain Matthew, Smith James A, Hansen Christopher S, Ashfold Michael N R
School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K.
J Phys Chem A. 2021 Nov 11;125(44):9594-9608. doi: 10.1021/acs.jpca.1c06346. Epub 2021 Oct 28.
The Coulomb explosion (CE) of jet-cooled CHI molecules using ultrashort (40 fs), nonresonant 805 nm strong-field ionization at three peak intensities (260, 650, and 1300 TW cm) has been investigated by multimass velocity map imaging, revealing an array of discernible fragment ions, that is, I ( ≤ 6), CH ( = 0-3), CH ( = 0, 2), C, H, H, and H. Complementary trajectory calculations of the CE of CHI cations with ≤ 14 identify a range of behaviors. The CE of parent cations with = 2 and 3 can be well-described using a diatomic-like representation (as found previously) but the CE dynamics of all higher CHI cations require a multidimensional description. The predicted I ( ≥ 3) fragment ion velocities are all at the high end of the velocity distributions measured for the corresponding I products. These mismatches are proposed as providing some of the clearest insights yet into the roles of nonadiabatic effects (and intramolecular charge transfer) in the CE of highly charged molecular cations.
利用多质量速度成像技术研究了喷射冷却的CHI分子在三种峰值强度（260、650和1300 TW/cm²）下的超短（40 fs）、非共振805 nm强场电离的库仑爆炸（CE），揭示了一系列可分辨的碎片离子，即I⁻（n ≤ 6）、CH⁺（n = 0 - 3）、CH₂⁺（n = 0, 2）、C⁺、H⁺、H₂⁺和H₃⁺。对n ≤ 14的CHI⁺阳离子的CE进行的补充轨迹计算确定了一系列行为。n = 2和3的母阳离子的CE可以用类似双原子的表示法很好地描述（如之前发现的那样），但所有更高n值的CHI⁺阳离子的CE动力学需要多维描述。预测的I⁻（n ≥ 3）碎片离子速度都处于相应I⁻产物测量的速度分布的高端。这些不匹配被认为是对高电荷分子阳离子CE中非绝热效应（和分子内电荷转移）的作用提供了一些迄今为止最清晰的见解。
