INTERACTION OF GROUND AND EXCITED STATES OF INDOLE DERIVATIVES WITH ELECTRON SCAVENGERS

The quantum yields and fluorescent lifetimes of a series of indole derivatives are reduced in the presence of a wide range of substances which are efficient scavengers of hydrated electrons. Deactivation of the excited state of the indole ring, which is solvated in polar or polarizable solvents, requires a direct collisional interaction with the scavenger. One possible mechanism for quenching is by abstraction of an electron from the excited indole by the scavenger although other mechanisms cannot be excluded. At higher concentrations of added quencher, ground state complexes of the scavenger with the indole may be formed in some cases.