Dynamical mechanism for the intermolecular relaxation of the excited NH stretching vibration of a pyrrole molecule in liquid solution Original Research Article

Nonlinear Dynamics is used to explain the intermolecular relaxation of the NH strechinng vibration of pyrrole in liquid phase. We present first a two mode model, which implies a 3:1 anharmonic resonance between the NH Morse stretch of an excited pyrrole molecule and the ring mode (harmonic stretch) of a neighboring pyrrole molecule coupled by a hydrogen bond interaction. Next, the model has been extended to three modes, in order to better mimic the real phenomenon. We present here the population decay and vibrational relaxation time of the NH stretch for both models.