BIMOLECULAR REACTION OF A LOCAL MODE VIBRATIONAL-STATE - H+H-2O(4-UPSILON-OH)-]OH(V,J)+H-2

Vibrational overtone excitation of water to the |04〉- local mode state is used to initiate the endothermic bimolecular reaction of hydrogen atoms with water molecules. A probe of the nascent OH product using laser-induced fluorescence indicates that this fragment receives less than 10% of the ∼9000 cm-1 of available energy consistent with a spectator model. Most of the OH fragments (∼98%) are formed in the vibrational ground state with an average of 360 cm-1 of rotational energy and ∼350 cm-1 of translational excitation. The present results on the H + H2O system demonstrate the feasibility of using vibrational overtone excitation to promote bimolecular reactions involving reagents containing light hydrogen atom stretching motion and, thus, investigate the influence of local mode excitation on chemical reactivity. © 1990 American Chemical Society.