Photodecomposition of MnO4-: A theoretical study

Citation
Gl. Gutsev et al., Photodecomposition of MnO4-: A theoretical study, J PHYS CH A, 103(50), 1999, pp. 10819-10824
Citations number
43
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHYSICAL CHEMISTRY A
ISSN journal
10895639 → ACNP
Volume
103
Issue
50
Year of publication
1999
Pages
10819 - 10824
Database
ISI
SICI code
1089-5639(199912)103:50<10819:POMATS>2.0.ZU;2-E
Abstract
The electronic and geometrical structures of the ground stated and low-lyin g isomers of MnO4 and MnO4- have been calculated as a function of spin-mult iplicities by using the molecular orbital theory based on generalized gradi ent approximation to the density functional formalism. Total energies of is omers are used for evaluating the energetics of the MnO4- decay through var ious fragmentation channels. Two primary channels were found depending on t he energy of photons. The preferred photofragmentation channel, accessible with approximate to 2 eV photons, is found to involve an initial excitation of the ground-state MnO4- anion into its peroxo isomer followed by subsequ ent excitations into a superoxo form. Photodetachment of an extra electron from this superoxo isomer anion leads to the formation of a neutral superox o isomer of MnO4, which, in turn, dissociates to MnO2 + O-2. Excitations of the anion peroxo isomer into biperoxo isomer are also possible with 3.7 eV , photons and the latter could dissociate spontaneously to MnO2- + O-2. A n umber of other decay channels are accessible with low-energy photons, but t heir intensities are expected to be Low because these require flipping the spin of one or more electrons.