Disentangling sequential and concerted fragmentations of molecular polycations with covariant native frame analysis
Disentangling sequential and concerted fragmentations of molecular polycations with covariant native frame analysis
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DOI：
10.1039/d2cp03029b
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发表时间：
2022-09-15
影响因子：
3.3
通讯作者：
Allum, Felix
中科院分区：
文献类型：
--
作者：
McManus, Joseph W.;Walmsley, Tiffany;Allum, Felix
我们目前的结果从实验离子成像研究的碎片动力学的1-碘丙烷和2-碘丙烷与极紫外强飞秒激光脉冲与光子能量为95 eV的相互作用。使用协方差成像分析，可以在相对高的离子计数率（类似于12个离子发射（-1））下分离和详细询问所得聚阳离子的一系列观察到的碎片化途径。通过将最近开发的本地帧分析方法的三维协方差成像过程中，从三体协调和顺序的碎裂机制的贡献可以被隔离。碎片离子的角分布比以前报道的三原子聚阳离子的研究复杂得多，并且在两种同分异构体之间有很大不同。与简单的模拟的支持感兴趣的解离通道，详细的物理见解的碎裂动力学，包括如何在一个连续的机制中的初始解离步骤的影响，在亚稳中间离子的振转动力学，以及如何签名的这种核运动表现在测量的信号。
We present results from an experimental ion imaging study into the fragmentation dynamics of 1-iodopropane and 2-iodopropane following interaction with extreme ultraviolet intense femtosecond laser pulses with a photon energy of 95 eV. Using covariance imaging analysis, a range of observed fragmentation pathways of the resulting polycations can be isolated and interrogated in detail at relatively high ion count rates (similar to 12 ions shot(-1)). By incorporating the recently developed native frames analysis approach into the three-dimensional covariance imaging procedure, contributions from three-body concerted and sequential fragmentation mechanisms can be isolated. The angular distribution of the fragment ions is much more complex than in previously reported studies for triatomic polycations, and differs substantially between the two isomeric species. With support of simple simulations of the dissociation channels of interest, detailed physical insights into the fragmentation dynamics are obtained, including how the initial dissociation step in a sequential mechanism influences rovibrational dynamics in the metastable intermediate ion and how signatures of this nuclear motion manifest in the measured signals.