Photodissociation of gas phase I{sub 3}{sup {minus}} using femtosecond photoelectron spectroscopy
- Department of Chemistry, University of California, Berkeley, California 94720 (United States)
The photodissociation dynamics of gas phase I{sub 3}{sup {minus}} following 390 nm excitation are studied using femtosecond photoelectron spectroscopy. Both I{sup {minus}} and I{sub 2}{sup {minus}} photofragments are observed; the I{sub 2}{sup {minus}} exhibits coherent oscillations with a period of 550 fs corresponding to {approximately}0.70 eV of vibrational excitation. The oscillations dephase by 4 ps and rephase at 45 and 90.5 ps on the anharmonic I{sub 2}{sup {minus}} potential. The gas phase frequency of ground state I{sub 3}{sup {minus}} is determined from oscillations in the photoelectron spectrum induced by resonance impulsive stimulated Raman scattering. The dynamics of this reaction are modeled using one- and two-dimensional wave packet simulations from which we attribute the formation of I{sup {minus}} to three-body dissociation along the symmetric stretching coordinate of the excited anion potential. The photodissociation dynamics of gas phase I{sub 3}{sup {minus}} differ considerably from those observed previously in solution both in terms of the I{sub 2}{sup {minus}} vibrational distribution and the production of I{sup {minus}}. {copyright} {ital 1999 American Institute of Physics.}
- OSTI ID:
- 359435
- Journal Information:
- Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 7 Vol. 111; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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