Ionization and ultrafast hydrogen migration of methylamine in few-cycle intense near-infrared laser fields

[Display omitted] •Methylamine is doubly ionized by a few-cycle intense near-infrared laser pulse.•Methylamine dication breaks into fragment ions via the singlet and triplet channels.•Kinetic energy releases of the Coulomb explosion are interpreted by DFT calculations.•Angular distributions of the fragments reflect the symmetries of HOMO of methylamine.•Ultrafast migration a hydrogen atom proceeds in methylamine cation and dication. Double ionization and ultrafast hydrogen migration of methylamine induced by a few-cycle intense near-infrared laser pulse are investigated by the coincidence momentum imaging method. By reference to the results obtained by DFT calculations, the peak profiles in the kinetic energy release distributions have been assigned to the singlet and triplet decomposition channels of CH3NH22+. The anisotropy in the angular distribution of the ejection direction of the fragment ions is interpreted based on the symmetries of the (7a’) HOMO orbital. By the pump–probe measurements, it is revealed that the ultrafast hydrogen migration in CH3NH2+ proceeds within ∼ 30 fs.