title: Near threshold Cl(-)·CH3I photodetachment: apparent 2P1/2 channel suppression and enhanced 2P3/2 channel vibrational excitation.
abstract: Cl(-)·CH(3)I cluster anion photoelectron images are recorded over a range of detachment wavelengths in the immediate post threshold region. The photoelectron spectral features fall into two categories. A number of weak, photon energy dependent transitions are observed and attributed to atomic anion fragmentation products. Several more intense, higher electron binding energy transitions result from single photon cluster anion detachment. Comparison with I(-)·CH(3)I suggests that the detachment process is more complicated for Cl(-)·CH(3)I. The single photon transition spacing is consistent with CH(3)I ν(3) mode excitation, but the two distinct vibronic bands of I(-)·CH(3)I detachment are not easily distinguished in the Cl(-)·CH(3)I spectra. Similarly, while the spectral intensities for both cluster anions show non-Franck Condon behavior, the level of vibrational excitation appears greater for Cl(-)·CH(3)I detachment. These observations are discussed in terms of low lying electronic states of CH(3)I along the C-I coordinate, and the influence of the CH(3)I moiety on the neutral halogen atom states.
authors.affiliation: Department of Chemistry, Washington University, Saint Louis, Missouri 63130, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Van Duzor
authors.forename: Foster
authors.initials: F
authors.lastname: Mbaiwa
authors.forename: Joshua
authors.initials: J
authors.lastname: Lasinski
authors.forename: Diep
authors.initials: D
authors.lastname: Dao
authors.forename: Nicholas
authors.initials: N
authors.lastname: Holtgrewe
authors.forename: Richard
authors.initials: R
authors.lastname: Mabbs