Long-Lived Neutral H2 in Hydrogen Migration Within Hydrocarbon Dication

First principles molecular dynamics calculations of energized CH3NH22+ and CH3CH32+ are performed to examine whether the formation of a long-lived neutral H-2 moiety identified in CH3OH in our previous study [Nakai et al., J. Chem. Phys. 139, 181103 (2013)] is a phenomenon commonly identified in energized hydrocarbon dications. A neutral H-2 moiety generated within a doubly charged parent ion is considered to play a crucial role in the hydrogen scrambling process in CH3CH32+, leading eventually to the ejection of H-3(+)