Vibrational Energy Transfer in a Water Chain

Abstract

Vibrational energy transfer through hydrogen bonding in water chains is a fast and efficient process. The chain consisting of 10 water molecules and a ground‐state nitric oxide at the end is collisionally excited by another nitric oxide molecule with an excess vibrational energy corresponding to in the v = 1 state from the other end, where the energy transfer proceeds through the hydrogen bonds. Energy transfer from the impact site to the end of chain occurs in a picosecond time scale, taking a subpicosecond over single hydrogen bond. The energy transfer pathway is a sequence of the initial OH‐stretching excitation on the impact to the OH bending overtone mode and then to the bound nitric oxide through a series of low‐frequency intermolecular vibrational states. More than 80% of the initial OH‐stretching excitation passes through the hydrogen bonds and deposits in the bound nitric oxide at the end of the chain. In the majority of trajectories, energy passing through the N…H bond at the terminal site leads to its subsequent bond rupture, thus producing a vibrationally excited nitric oxide in the region remote from the initial impact site.