State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China.
Phys Rev Lett. 2014 Jun 20;112(24):243001. doi: 10.1103/PhysRevLett.112.243001. Epub 2014 Jun 18.
We investigate dissociative double ionization of acetylene, one of the smallest organic molecules yet with a rich electronic structure, in strong laser fields by measuring two fragment ions and two electrons in coincidence. The two-body fragmentation channels are dominated by the removal of electrons from the lower-lying molecular orbitals rather than from the highest occupied one. The electron localization-assisted enhanced ionization mechanism plays a central role for the strong-field deprotonation ionization of acetylene by releasing the second electron from the up-field potential well of the hydrogen site at the internuclear distance near twice the equilibrium value of the C-H bond.
我们通过测量两个碎片离子和两个电子的符合来研究乙炔的离解双电离，乙炔是最小的有机分子之一，但具有丰富的电子结构，在强激光场中。两种体碎裂通道主要是从较低的分子轨道而不是从最高占据轨道去除电子。电子局域辅助增强电离机制对于乙炔的强场去质子化电离起着核心作用，通过从氢位的上磁场阱中释放第二个电子，将第二个电子释放出来，此时氢位的内距接近 C-H 键平衡值的两倍。
