PHOTOCHEMISTRY OF METHANE IN THE PHOTOIONIZATION REGION.

Abstract

Methane was irradiated with microwave operated helium (21. 2 eV) and neon (16. 7-16. 8 eV) resonance lamps which were separated from the reaction vessel by an aluminum window. The quantum yields of the stable end products have been determined at methane pressures ranging from 1 to 20 torr. There is no evidence for the formation of neutral fragments such as H//2, C, CH or CH//2 at 16. 7-16. 8 eV. The fact that the ionization quantum is equal to unity in this energy range accounts for the absence of these intermediates.