Mean Lifetime of the Fluorescence of Acetone and Biacetyl Vapors

Abstract

The effects of pressure, temperature, and exciting intensity on the lifetime of fluorescence of acetone and biacetyl vapor have been investigated. The pressure dependence of the lifetime in acetone was interpreted in terms of the formation of double molecules, and part of the temperature dependence was interpreted in terms of the formation of double molecules. The lifetime in biacetyl was found to be independent of pressure at a constant temperature, but dependent on temperature. The effect of oxygen on the lifetime in biacetyl was explained by assuming a simple Stern‐Volmer mechanism for quenching. The lifetimes of fluorescence in both acetone and biacetyl were found to be dependent on the incident intensity. This effect was explained by assuming that the fluorescing molecules of both compounds were quenched by the products of photochemical decomposition.