Photolysis of O₂ dispersed in solid neon with far-ultraviolet radiation

Abstract

Irradiation at 173 or 143 nm of samples of O or O in solid Ne near 4 K produced many new spectral lines in absorption and emission from the mid-infrared to the near-ultraviolet regions. The major product was ozone, O, that was identified with its mid-infrared and near-ultraviolet absorption lines. Oxygen atoms were formed on photolysis of O and stored in solid neon until the temperature of a sample was increased to 9 K, which enabled their migration and combination to form O and likely also O. O in five excited states and O in two excited states detected through the emission spectra indicate that complicated processes occurred in solid Ne after far-ultraviolet excitation. For the transition D → P of O, the lifetime was determined to be 5.87 ± 0.10 s; the lifetime of the upper state of an unidentified transition associated with an emission feature at 701.7 nm was determined to be 2.34 ± 0.07 s.

CHAPTER 2. Extraterrestrial Photochemistry: Principles and Applications

“…Absorption spectra of molecular oxygen (a) gas phase, (b) O 2 in solid Ne, (c) solid O 2 at 10 K. 55 Alternatively, one can think about condensed-phase photochemistry using a diabatic basis, where each state can be directly assigned chemical significance (e.g., "reactants" live on State 1, and "products" live on State 2). 56 The kinetics and dynamics of condensed-phase photochemistry can be studied in a diabatic basis by applying one of various system-bath models, including the spin-boson model, the Redfield equation, 57 or the hierarchical equation of motion, among others.…”

Vacuum-Ultraviolet Absorption Spectra of Icy C2H4 at 13–60 K

“…The gaseous molecule behaves as isolated, with no perturbation from other molecules; its spectral profile hence reveals the intrinsic properties of a single molecule. In contrast, the molecules in condensed phases are inevitably involved in intermolecular interactions with adjacent molecules; their spectra hence invariably involve the collective effects of the molecules in the condensed state (Lu et al, 2005;Chou et al, 2018;Lo et al, 2018).…”

Formation and Stabilization of Ground and Excited-State Singlet O2 upon Recombination of 3P Oxygen on Amorphous Solid Water

“…However, this process has been found to involve a barrier of ∼17 kcal/mol and is therefore not expected to play a role under cold conditions. 9 Experimental spectroscopic observations show that recombination of two oxygen atoms ( 3 P) generated from photolysis of 16 O 2 using far-ultraviolet light in neon matrices at low temperature (T ∼ 5 K) leads to formation of O 2 in its X 3 Σ g − , a 1 Δ g , b 1 Σ g + , and additionally, more highly excited electronic states, 10 although the relative populations of the states were not reported. The first ( 1 Δ g ) and second ( 1 Σ g + ) excited states are of particular interest, due to their higher reactivity compared to the ground state.…”