Spectroscopy and fluorescence lifetimes of jet-cooled 7-azaindole: Electronic states and solvent complex geometry

Additional spectroscopic studies have been carried out on jet-cooled 7-azaindole and 7-azaindole clusters with polar solvent adducts, primarily water. New lifetime data and more extended excitation scans strengthen an earlier conclusion that S-1 levels mix with nearby levels from another electronic state. Our complete data set indicates the likelihood of mixing with (1)L(a) rather than with n pi*, as was previously postulated. The excitation and dispersed emission spectra suggest that addition of one water to the chromophore induces (1)L(a) emission. Polar solvent induction of (1)L(a) emission in 7-azaindole bears some similarities to analogous phenomena in conventional indoles.