Influence of 3-Substitution on Excited State Properties of Indole in Aqueous Solutions

Considerable attention has been paid to the excited states of the indole ring in the past two decades, since as, the aromatic moiety of tryptophan, it is the major near-ultraviolet chromophore of proteins where it can play the role of a fluorescent probe. Nevertheless photophysical and photochemical properties of indole are rather particular and remain largely unelucidated (Longworth, 1971).