Abstract
The application of photochemical information to the characterization of primary processes is discussed; the selection of proper experimental conditions is of crucial importance in order to avoid ambiguous or misleading interpretations of such data. As an example, the existing data on the photolysis of biacetyl in the range λ 4358–3660 A is analyzed. The treatment indicates the presence of a single process with an activation energy E=13 300 cal/mole and a frequency factor v=1.5×1013 sec—1.