Radiative Lifetime of Triplet Biacetyl

Abstract

Absolute quantum yields of phosphorescence of biacetyl have been obtained in fluid and rigid solutions. In fluid solutions, the measurements were made relative to the quinine bisulfate standard and in rigid media, relative to benzophenone. The values obtained have been taken together with the known triplet‐state lifetimes of biacetyl in these media to calculate the radiative lifetime of triplet biacetyl. These results compare favorably with the radiative lifetime of biacetyl triplet in the gas phase, calculated in a similar manner using available data on the phosphorescence yield and the actual mean life in the vapor.