EFFECT OF VISCOSITY ON FLUORESCENCE OF ANTHRACENES IN SOLUTION

The fluorescence quantum yields of 9‐alkylated anthracenes vary appreciably with solvent viscosity at 22 °C, while those of anthracene and 9,10‐dimethyl‐anthracene do not. The increase in fluorescence quantum yield in a more viscous solvent is due to a decrease in the rate of nonradiative decay. (AIP)