Stark effect measurements of the +280 cm(-1) vibronic band at similar to 286 nm in the high resolution S-1-S-0 fluorescence excitation spectrum of 7-azaindole (7AI) in a molecular beam show that the permanent (electric) dipole moment (PDM) of the upper state vibrational level reached in this transition is 4.6 D, twice as large as the PDM of the zero-point level of the S-1 state. This large difference is attributed to state mixing with a more polar state. EOM-CSSD calculations suggest that this more polar state is sigma pi* in nature and that it crosses the pi pi* state in energy along the coordinate connecting the two potential energy minima. Such state mixing apparently provides more facile access to conical intersections with the ground state, and subsequent hydrogen atom detachment reactions, since independent studies by Sakota and Sekiya have shown that the N-H stretching frequency of 7AI is significantly reduced when it is excited to the +280 cm(-1) vibrational level of the S-1 state.