Abstract

7-Azaindole (7AI) is one of a class of molecules that exhibit dual fluorescence as a result of excited-state tautomer formation. The tautomer is reached through a proton transfer from the initially excited "normal" form, the only form present in the ground electronic state. When isolated (in the gas phase or in non-hydroxylic solvents) 7AI does not tautomerize at an observable rate. However, in non-polar solvents, 7-azaindole forms dimers which enable the excited-state tautomerization to occur via a double proton transfer mechanism. Tautomerization in 7AI dimers has been studied for quite some time as a possible model for DNA mutagenesis [1]. Recent measurements have shown that the dimer the reaction is quite facile, occurring in ~1 ps at room temperature [2].

© 1992 The Author(s)