Dynamics of vibronically excited states of the aniline–neon van der Waals complex: vibrational predissociation versus intramolecular vibrational redistribution

New data on the high resolution spectra of vibronic bands of the aniline–neon van der Waals complex with excess vibrational energy up to 1000 cm−1 above the S1 origin have been obtained. The rotationally resolved structure of the 1210 and 6a20 bands of both 20Ne–aniline and 22Ne–aniline isotopomers reveal: (1) a dynamical contribution to the linewidth of the molecular eigenstates, (2) the existence of an accidental perturbation responsible for a local increase of the relaxation rate. The results are interpreted in terms of the competition between intramolecular vibrational redistribution and direct vibrational pre-dissociation processes.