Electron-Induced Synthesis of Ozone in a Dioxygen Matrix

Ozone (O3) was synthesized in the condensed phase induced by electron bombardment of multilayer films of molecular oxygen condensed at temperatures below 30 K on metal surfaces. O3 formation was demonstrated by the observation of the asymmetric stretching (v3) and bending (v2) normal modes of vibration in a high-resolution electron energy-loss spectroscopy experiment, and by characteristic changes in electron-stimulated desorption of O-. The threshold electron energy for the O3 formation is found at 3.5±0,2 eV. It corresponds to the formation of O(3P) associated with O-(2P) by dissociative electron attachment at condensed O2, followed by the third body reaction O+O2 +O2→O3+O2. Above 5.1 eV bombarding energy, dissociative excitation of the O̊̇̑2̑ (c1Σu -,C3Δu,A3Σu+ ,B3Σu-) states is the main source of atomic oxygen O(3P) or O(1D) involved in the O3 synthesis