ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Both one- and two-color zero kinetic energy-pulsed field ionization (ZEKE-PFI) spectra of the first electronically excited state of I+2 (A 2Π3/2,u) as well as a new electronic state, the a 4Σ−u state, have been recorded for the first time. In the one-color (two photon) experiment, transitions to the quartet state are formally spin-forbidden and this is reflected in the weak transition intensity observed compared with the A 2Π3/2,u state. However, in the two-color (1+2′) experiment, which used the valence B 3Π0+u state as an intermediate, transitions into both A 2Π3/2,u and a 4Σ−u states are fully allowed and appear in the spectrum with comparable intensity. The a 4Σ−u state appears in the one-color experiment by virtue of spin–orbit coupling with excited electronic states for which direct ionization from the neutral ground state is fully allowed. Values for ω¯exe of 0.46±0.01 cm−1 for the A 2Π3/2,u state and 0.38±0.02 cm−1 for the a 4Σ−u state were derived, together with lower limits for ω¯e of 138±2 and 128±2 cm−1, respectively. In addition, highly vibrationally excited levels of the X 2ΠΩ,g state have been probed in the one-color experiments, by exploiting a propensity for extensive electronic autoionization involving Rydberg states based on the excited X 2Π1/2,g and A 2ΠΩ,u states as well as the dissociative B 2Σ+g state. In the case of the X 2Π3/2,g ground state, the vibrational progression extends as far as v+=90 while that associated with the X 2Π1/2,g state extends as far as v+=40. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.472535
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