Fluorescence and thermoluminescence of N2O, CO, and CO2 in an argon matrix at low temperature

The photolysis of N2O in an argon matrix at 7 °K by 8.4 eV energy photons leads to the emission of the Vegard–Kaplan system of N2 (A 3Σ+→X 1Σ+g) and to the atomic emissions O(1S) →O(1D) and N(2D) →N(4S). The thermoluminescence which accompanies an increase of the matrix temperature is due to O2 (A 3Σ+u→X 3Σ−g). In the presence of CO, the atomic oxygen emission disappears and the CO (a 3Π→X 1Σ) Cameron System is detected. The thermoluminescence in this case is a continuum (3800–5000 Å) apparently due to CO2 (3B2→X 1Σ+g) showing that ground state oxygen atoms, O(3P), react with CO at cryogenic temperatures: CO (X 1Σ+)+O(3P) →CO2(3B2), CO2(3B2) →CO2(X 1Σ+g)+hν.