The unusual long-wavelength shift and bandwidth of the fluorescence spectra of 7-azaindole in alcohol and water solutions compared with hydrocarbon solution is demonstrated to be the result of exciplex formation between the 7-azaindole and the hydroxylic solvent molecules. The technique of monitoring the fluorescence band position, intensity, and half-width (fwhm) in alcohol-hydrocarbon solutions as developed by Walker et al. has been used to distinguish the exciplex model from other existing models. Aggregation effects and the dependence of the exciplex fluorescence yield on alcohol acidity have led to a model attributing excited-state charge transfer between the nonbonding oxygen electrons in the alcohol and the lowest vacant ..pi.. orbital of excited 7-azaindole. It also has been demonstrated that excited-state double proton transfer between 7-azaindole and a single alcohol molecule occurs, independent of the exciplex formation, for molecules that form a cyclic hydrogen-bonded complex in the ground state.