Structure and hydrogen bond vibrations of the jet-cooled 1:1 complex between 7-azaindole and formamide: A laser-induced fluorescence spectroscopy study

► Laser-induced fluorescence spectra of 7-azaindole⋯formamide complex are measured in a supersonic free jet expansion. ► Electronic structure calculation predicts a doubly hydrogen bonded cyclic geometry of the complex. ► Hydrogen-bond vibrations of the complex in the ground state are measured. ► The complex does not undergo excited state tautomerization, which is consistent with TDDFT and CIS calculations.