A photoion--photoelectron coincidence study of (N/sub 2/)/sub 2/ and (N/sub 2/)/sub 3/
The photoion--photoelectron coincidence (PIPECO) spectra for (N/sub 2/)/sup +//sub 2/ in the wavelength range 650--866 A have been measured at different nozzle stagnation pressures. The formation of stable (N/sub 2/)/sup +//sub 2/ from fragmentation of excited (N/sub 2/)/sup +//sub /ital n// cluster ions initially produced by photoionization of (N/sub 2/)/sub /ital n//, /ital n/greater than or equal to3, is efficient. For nozzle expansion conditions which minimize the production of (N/sub 2/)/sub /ital n//, /ital n/greater than or equal to3, the intensities for the N/sup +//sub 2/(/ital A/tilde //,/ital B/tilde //)/center dot/N/sub 2/ PIPECO bands are found to be negligibly small compared to that of the N/sup +//sub 2/(/ital X/tilde //)/center dot/N/sub 2/ PIPECO band, indicating that the electronically excited N/sup +//sub 2/(/ital A/tilde //,/ital B/tilde //)/center dot/N/sub 2/ dimer ions are dissociative in temporal ranges /lt/42 ..mu..s. Assuming that the radiative lifetimes for N/sup +//sub 2/(/ital A/tilde //,/ital B/tilde //) and N/sup +//sub 2/(/ital A/tilde //,/ital B/tilde //)/center dot/N/sub 2/ are identical, we estimate that the dissociative lifetimes for N/sup +//sub 2/(/ital A/tilde //)/center dot/N/sub 2/ and N/sup +//sub 2/(/ital B/tilde //)/center dot/N/sub 2/ are /approx lt/10 ..mu..s and /approx lt/60 ns, respectively. The ionization energy for (N/sub 2/)/sub 2/ is determined to be 14.50+-0.08 eV (855+-5 A), suggesting that N/sup +//sub 2/(/ital X/tilde //)/center dot/N/sub 2/ is bound by 1.09+-0.08 eV. The PIPECO data for (N/sub 2/)/sup +//sub 2/ presented here and those for (CO)/sup +//sub 2/ reported previously support the perturbed monomer ion model for the photoionization of a van der Waals cluster.
- Research Organization:
- Ames Laboratory, U. S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011(US)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 5923874
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 91:2; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ADDUCTS
CHEMICAL BONDS
COINCIDENCE SPECTROMETRY
DIMERS
DISSOCIATION ENERGY
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY
IONIZATION
NITROGEN
NONMETALS
PHOTOELECTRON SPECTROSCOPY
PHOTOIONIZATION
SPECTROSCOPY