Ultrafast molecular dynamics in ionized 1- and 2-propanol: from simple fragmentation to complex isomerization and roaming mechanisms
Ultrafast molecular dynamics in ionized 1- and 2-propanol: from simple fragmentation to complex isomerization and roaming mechanisms
复制标题
电离 1- 和 2- 丙醇中的超快分子动力学：从简单的裂解到复杂的异构化和漫游机制
DOI：
10.1039/d1cp04011a
复制
发表时间：
2021
影响因子：
3.3
通讯作者：
Berrah, Nora
中科院分区：
文献类型：
--
作者：
Mishra, Debadarshini;Reino-González, Juan;Obaid, Razib;LaForge, Aaron C.;Díaz-Tendero, Sergio;Martín, Fernando;Berrah, Nora
在光激发时，分子可以经历许多复杂的过程，例如异构化和漫游，导致分子和电子结构的变化。在这里，我们报告的时间分辨的超快核动力学，激光电离，在两个结构异构体，1-和2-丙醇，使用泵探测光谱和符合库仑爆炸成像的组合。我们的测量，与量子化学计算配对，确定所观察到的两个异构体的两体和三体解离通道的机制。特别是，2-丙醇的碎片通道与损失的CH 3显示可能的证据甲基漫游。此外，这种漫游甲基片段的电子结构可能是负责增强电离也观察到该通道。最后，与对乙醇和乙腈进行的类似研究进行比较有助于建立烷基链长度与氢迁移可能性之间的相关性。
Upon photoexcitation, molecules can undergo numerous complex processes, such as isomerization and roaming, leading to changes in the molecular and electronic structure. Here, we report on the time-resolved ultrafast nuclear dynamics, initiated by laser ionization, in the two structural isomers, 1- and 2-propanol, using a combination of pump–probe spectroscopy and coincident Coulomb explosion imaging. Our measurements, paired with quantum chemistry calculations, identify the mechanisms for the observed two- and three-body dissociation channels for both isomers. In particular, the fragmentation channel of 2-propanol associated with the loss of CH3 shows possible evidence of methyl roaming. Moreover, the electronic structure of this roaming methyl fragment could be responsible for the enhanced ionization also observed for this channel. Finally, comparison with similar studies done on ethanol and acetonitrile helps establish a correlation between the length of the alkyl chain and the likelihood of hydrogen migration.