Mechanism of fluorescence quenching in solution. Part 2.—Quenching by xenon and intersystem crossing efficiencies

Abstract

The solubility of xenon in 95 % ethanol is shown to be sufficient to quench the fluorescence of aromatic hydrocarbons with high efficiency. Quenching is due to catalyzed intersystem crossing from the first excited singlet state eventually producing the lowest triplet state. Quenching constants are given for nine molecules and the quantum yields ϕ_T of triplet state production of pyrene and 9-phenylanthracene in 95 % ethanol have been measured. Xenon gas is shown to be an ideal fluorescence quencher for determining ϕ_T in solution.