ELECTRON-INDUCED SYNTHESIS OF OZONE IN A DIOXYGEN MATRIX

Ozone (O-3) was synthesized in the condensed phase induced by electron bombardment of multilayer films of molecular oxygen condensed at temp eratures below 30 K on metal surfaces. O-3 formation was demonstrated by the observation of the asymmetric stretching (nu(3)) and bending (n u(2)) normal modes of vibration in a high-resolution electron energy-l oss spectroscopy experiment, and by characteristic changes in electron -stimulated desorption of O-. The threshold electron energy for the O- 3 formation is found at 3.5 +/- 0.2 eV. It corresponds to the formatio n of O(P-3) associated with O-(P-2) by dissociative electron attachmen t at condensed O-2, followed by the third body reaction O + O-2+ O-2 - -> O-3 + O-2. Above 5.1 eV bombarding energy, dissociative excitation of the O-2 (c(1) Sigma(u)(-),C-3 Delta(u),A(3) Sigma(u)(+), B-3 Sigma (u)(-) states is the main source of atomic oxygen O(P-3) or O(D-1)invo lvedin the O-3 synthesis.