title: Nuclear spatial delocalization silences electron density oscillations in 2-phenyl-ethyl-amine (PEA) and 2-phenylethyl-N,N-dimethylamine (PENNA) cations.
abstract: We simulate electron dynamics following ionization in 2-phenyl-ethyl-amine and 2-phenylethyl-N,N-dimethylamine as examples of systems where 3 coupled cationic states are involved. We study two nuclear effects on electron dynamics: (i) coupled electron-nuclear motion and (ii) nuclear spatial delocalization as a result of the zero-point energy in the neutral molecule. Within the Ehrenfest approximation, our calculations show that the coherent electron dynamics in these molecules is not lost as a result of coupled electron-nuclear motion. In contrast, as a result of nuclear spatial delocalization, dephasing of the oscillations occurs on a time scale of only a few fs, long before any significant nuclear motion can occur. The results have been rationalized using a semi-quantitative model based upon the gradients of the potential energy surfaces.
authors.affiliation: Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Jenkins
authors.affiliation: Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Morgane
authors.initials: M
authors.lastname: Vacher
authors.affiliation: Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bearpark
authors.affiliation: Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Robb