Photodissociation of ozone in the K edge region

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 degrees relative to the electric vec tor of linearly polarized soft X-ray. In the K shell excitation at the 529 eV photoabsorption peak, the energetic O+ fragment ion was ejected anisotro pically, while at the 536 eV band it was isotropic. The beta values calcula ted from simulation of the TOF spectra are consistent with the previous ass ignments that the 529 eV band is the pi* <-- O-T(1s) resonance excitation a nd that the 536 eV band mainly consists of two transitions, pi*(2b(1)) <-- O-C(1s) and sigma*(7a(1)) <-- O-T(1s) [Gejo et al. Chem. Phys. Lett. 277 (1 997) 497]. The TOF spectra show that the pi* excitation of terminal oxygen atoms generates more O-2(+) fragment than the excitation of the center oxyg en atom.