Pathways of relaxation of the N–H stretching vibration of pyrrole in liquids

The v=1, N–H vibrational excitations of pyrrole flow with high selectivity into ring breathing motions. The process is intermolecular, involving a coupling of H motion in one pyrrole with the π system of another pyrrole or benzene molecule in the solution. The inter- and intramolecular contributions to vibrational relaxation are experimentally distinguished.