학술논문

Step-by-step state-selective tracking of fragmentation dynamics of water dications by momentum imaging
Document Type
article
Source
Nature Communications. 13(1)
Subject
Physical Sciences
Chemical Sciences
Atomic
Molecular and Optical Physics
Physical Chemistry
CSD-01-AMOS-A
CSD-46-All CSGB
CSD-45-Featured
Language
Abstract
The double photoionization of a molecule by one photon ejects two electrons and typically creates an unstable dication. Observing the subsequent fragmentation products in coincidence can reveal a surprisingly detailed picture of the dynamics. Determining the time evolution and quantum mechanical states involved leads to deeper understanding of molecular dynamics. Here in a combined experimental and theoretical study, we unambiguously separate the sequential breakup via D+ + OD+ intermediates, from other processes leading to the same D+ + D+ + O final products of double ionization of water by a single photon. Moreover, we experimentally identify, separate, and follow step by step, two pathways involving the b 1Σ+ and a 1Δ electronic states of the intermediate OD+ ion. Our classical trajectory calculations on the relevant potential energy surfaces reproduce well the measured data and, combined with the experiment, enable the determination of the internal energy and angular momentum distribution of the OD+ intermediate.