Rotationally resolved electronic spectroscopy of aniline excited vibronic levels

Experiments of molecular beam high resolution electronic spectroscopy were performed on several vibronic bands of the S1←S0 electronic transition of aniline. Here we report on the properties of the excited states with a vibrational energy up to 1300 cm−1 above the fundamental vibrational level of S1. The spectroscopic parameters of these levels, such as band centers and rotational constants, have been determined with high accuracy from the fit of more than 300 ro-vibronic transitions for each band. Each single ro-vibronic transition was found to be homogeneously broadened by about 18 MHz and no evidence of spectral perturbation was detected.