Photodissociation of Ozone in the K Edge Region

Abstract

Dissociative dynamics of the K shell excited ozone has been investigated by time-of-flight (TOF) mass spectra of fragment ions for the first time. The TOF spectra were acquired at 0 and 90°relative to the electric vector of linearly polarized soft X-ray. In the K shell excitation at the 529 eV photoabsorption peak, the energetic O + fragment ion was ejected anisotropically, while at the 536 eV band it was isotropic. The β values calculated from simulation of the TOF spectra are consistent with the previous assignments that the 529 eV band is the π* r O T (1s) resonance excitation and that the 536 eV band mainly consists of two transitions, π*(2b 1 ) r O C (1s) and σ*(7a 1 ) r O T (1s) [Gejo et al. Chem. Phys. Lett. 277 (1997) 497]. The TOF spectra show that the π* excitation of terminal oxygen atoms generates more O 2 + fragment than the excitation of the center oxygen atom.

High-Resolution Inner-Shell Photoabsorption and Dissociation of Ozone

“…The fwhm (full width at half-maximum) values for the three Voigt peaks were 1.06, 1.05, and 1.48 eV for the states A, B, and C, respectively. The experimental relative intensity and the fwhm found for the B and C components of the second spectral band are close to the ones shown in Figure b of ref . The calculated oscillator strength of the O C (π*) and O T (σ*) transitions appears over-estimated with respect to the first calculated transition and also to the intensity ratio observable for the two valence experimental peaks.…”

“…The latter technique has been proved to be an effective method to characterize core excited states formed by photoabsorption in small molecules. − In the present work the very low O 2 contamination of the ozone sample allowed new features to be clearly observed in the high energy spectral region. If oxygen is present, , this region contains highly structured and intense Rydberg features of O 2 that overlap bands of O 3 making their observation and assignment difficult.…”

Molecular Size Effect on the Site Dependent Photofragmentation of N and O K-Shell Excited CH3CO(CH2)nCN (n = 0−3)

“…It has been of great interest to observe the products formed by the excitation of the innermost 1s electron of a specific atom in a molecule. Such evidences for atom-selective soft X-ray chemistry of gaseous molecules have been studied for N 2 O, , O 3 , CF 2 CH 2 , CF 3 CH 3 , , chlorofluorocarbons, − (CH 3 ) 2 CO, Pb(CH 3 ) 4 , n- and 2-propanol, and other organic molecules, , by exciting K-edges. These works have been performed with the expectation that a chemical bond scission can occur in a limited area around the atomic site of excitation; that is, a site specific reaction following normal and/or resonance Auger decay is to be expected.…”

Core excitation in O3 localized to one of two symmetry-equivalent chemical bonds: Molecular alignment through vibronic coupling

“…Core excited O 3 has been studied both with ion and electron spectroscopy [1,2,3,4,5]. The core-excited state O T 1s −1 7a 1 1 has been shown to be ultra-fast dissociating [4].…”

“…Core excited O 3 has been studied both with ion and electron spectroscopy [1,2,3,4,5]. The core-excited state O T 1s −1 7a 1 1 has been shown to be ultra-fast dissociating [4]. Ultra-fast dissociating molecules dissociate on the same time scale as the electronic Auger decay, which is in the femtosecond range.…”