Photoelectron Spectra of the Halogens

摘要: Photoelectron spectra of valence shell electrons in F2, Cl2, Br2, and I2 yield information on the molecular electronic structure lowest several states corresponding positive ions, some which is not available from previous spectroscopic studies. Spin–orbit fine resolved for ground 2Πg F2+ Cl2+; values obtained are ζ = 337 ± 40 645 ± 40 cm−1, respectively. The first excited ions identified as 2Πu approximate ζ = 2000–2200 6400 cm−1 Br2+ (A 2Πu) I2+(A 2Πu), A state reported previously [D. C. Frost, A. McDowell, D. Vroom, J. Chem. Phys. 46, 4255 (1967)] to lie at ∼ 17.4 eV observed here attributed nitrogen impurity. Vibrational frequencies Cl2+(X 2Πg) agreement with work. I2+ ωe = 360 ± 40 ∼ 220 cm−1. change bond length Br2+(2Πg) Δre ∼ (−)0.095 estimated fr...