Hydrogen migration in acetonitrile in intense laser fields in competition with two-body Coulomb explosion
Hydrogen migration in acetonitrile in intense laser fields in competition with two-body Coulomb explosion
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DOI：
10.1016/j.elspec.2004.06.009
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发表时间：
2004-12-01
影响因子：
1.9
通讯作者：
Yamanouchi, K
中科院分区：
文献类型：
--
作者：
Hishikawa, A;Hasegawa, H;Yamanouchi, K
利用符合动量成像方法研究了乙腈（CH₃CN）和氘代乙腈（CD₃CN）在强激光场（0.15拍瓦/平方厘米，70飞秒）中的双体库仑爆炸过程，CH₃CN²⁺→CH₃₋ₙ⁺ + HₙCN⁺以及CD₃CN²⁺→CD₃₋ₙ⁺ + DₙCN⁺（n = 0 - 2）。三种途径（n = 0 - 2）所得到的相当的产率表明氢原子迁移与库仑爆炸相互竞争。当n = 0时，碎片离子的角分布在激光偏振方向上呈现出一个尖锐的峰，而随着n的增加角分布变得更加各向同性。基于对碎片各向异性的最小二乘法分析，确定了双电荷乙腈的解离寿命，并由此讨论了氢迁移的时间尺度以及爆炸前C - C - N骨架的变形。（C）2004爱思唯尔有限公司。保留所有权利。
Two-body Coulomb explosion processes of acetonitrile (CH3CN) and deuterated acetonitrile (CD3CN), CH3CN2+ --> CH3-n+ +HnCN+ and CD3CN2+ --> CD3-n+ +DnCN+ (n = 0-2), in an intense laser field (0.15 pW/cm(2), 70 fs) are investigated by the coincidence momentum imaging method. The comparable yields derived for the three pathways (n = 0-2) shows that the hydrogen atom migration proceeds in competition with the Coulomb explosion. The angular distributions of the fragment ions for n = 0 exhibits a sharp peak along the laser polarization direction while the angular distribution becomes more isotropic as n increases. Based on a least-squares analysis of the fragment anisotropy, the dissociation lifetimes of the doubly charged acetonitrile were determined, from which the time scale of the hydrogen migration as well as the deformation of the C-C-N skeleton prior to the explosion were discussed. (C) 2004 Elsevier B.V. All rights reserved.