Fragmentation of metastable SF6−∗ ions with microsecond lifetimes in competition with autodetachment

K. Graupner, T. A. Field, A. Mauracher, P. Scheier, A. Bacher, S. Denifl, F. Zappa, T. D. Märk
2008 Journal of Chemical Physics  
Fragmentation of metastable SF 6 − * ions formed in low energy electron attachment to SF 6 has been investigated. The dissociation reaction SF 6 − * → SF 5 − + F has been observed ϳ1.5-3.4 s and ϳ17-32 s after electron attachment in a time-of-flight and a double focusing two sector field mass spectrometer, respectively. Metastable dissociation is observed with maximum intensity at ϳ0.3 eV between the SF 6 − * peak at zero and the SF 5 − peak at ϳ0.4 eV. The kinetic energy released in
more » ... n is low, with a most probable value of 18 meV. The lifetime of SF 6 − * decreases as the electron energy increases, but it is not possible to fit this decrease with statistical Rice-Ramsperger-Kassel/quasiequilibrium theory. Metastable dissociation of SF 6 − * appears to compete with autodetachment of the electron at all electron energies.
doi:10.1063/1.2884346 pmid:18345885 fatcat:xcp4gpgx2bdnrh2dadpah64jui