Effect of 1,4-diazabicyclo-[2,2,2]-octane on the laser properties of 7-amino coumarin dyes

Abstract

1,4-Diazabicyclo-[2,2,2]-octane (Dabco), a tertiary amine, was found to quench the fluorescence of two 7-amino coumarin dyes C1 and C102. The quenching was monitored in solvents of varying polarity. In non-polar and polar aprotic solvents the quenching is very efficient and the rate constants for quenching are within diffusion-controlled limits, whereas in protic solvents the quenching efficiency is very low. An attempt has also been made to delineate the mechanism for the stabilization of a dye laser by Dabco, following the reactions of the triplets of C1 with Dabco and also by monitoring the photodegradation of C1 in the presence of Dabco.