Photodissociation of gas phase I{sub 3}{sup {minus}} using femtosecond photoelectron spectroscopy

Journal Article · Sun Aug 01 04:00:00 EDT 1999 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.479660· OSTI ID:359435

Zanni, M T; Greenblatt, B J; Davis, A V; Neumark, D M ^[1]

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1. 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

Related Subjects

40 CHEMISTRY
ANIONS
DISSOCIATION
GROUND STATES
IODINE
MOLECULAR IONS
PHOTOCHEMICAL REACTIONS
PHOTOELECTRON SPECTROSCOPY