title: Adiabatic ionization energies of the overlapped A(2)A1 and B(2)E electronic states in CH3Cl(+)/CH3F(+) measured with double imaging electron/ion coincidence.
abstract: Utilizing the vacuum ultraviolet (VUV) synchrotron radiation and a double imaging photoelectron photoion coincidence (i(2)PEPICO) technique, we have measured the adiabatic ionization energies (AIEs) of the overlapped A(2)A1 and B(2)E electronic states of CH3Cl(+) and CH3F(+) ions. We show that the two overlapped electronic states can be separated in the electron and ion kinetic energy correlation diagrams based on their state-specific dissociation dynamics, leading to different kinetic energies released in dissociation, along the CH3(+) fragmentation channel. Thus the correlation diagrams yielded values of 13.67 ± 0.03 and 14.77 ± 0.03 eV for the AIEs of the A(2)A1 and B(2)E states of CH3Cl(+), and 16.08 ± 0.03 and 17.00 ± 0.05 eV for CH3F(+), respectively. This method can be generalized to separate ionic states that are otherwise overlapped in normal photoelectron spectra (PES), especially by combining VUV sources and electron/ion coincidence techniques.
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France. xiaofeng.tang@synchrotron-soleil.fr.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Tang
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Garcia
authors.forename: Laurent
authors.initials: L
authors.lastname: Nahon