Effect of reagent rotation on product energy disposal in the light atom transfer reaction Q³P]+HCI(v=2,J= 1,6,9)→OH(v′,N′) +Cl(²P)

Abstract

A rovibronic-state-to-rovibronic-state experiment has been performed on the reaction O(3P) + HCl(v = 2,J = 1,6,9) →OH(v′,N′) + O(3P). The O(3P) atoms are produced with a known energy by photolysis of NO2. The HCl(v = 2,J) molecules are prepared by IR excitation of thermal HCl using an optical parametric oscillator. All energetically accessible OH rovibrational product levels are probed by laser-induced fluorescence for each prepared HCl rotational level. The OH(v′ = 0,N′) rotational distribution shows a dip at N′ = 11, the depth of which decreases with increasing HCl rotational excitation. The available energy of reaction is partitioned so that 40% appears as OH vibration (V′), 32% as OH rotation (R′), and 28% as product translation (T′). This energy partitioning does not change with HCl rotation, in contrast to the general expectation for light atom transfer reactions of approximate conservation of internal angular momentum (R→R′). A substantial vibrational inversion is observed, in agreement with the vibrational adiabaticity (V→V′) expected for such reactions. © 1991 American Institute of Physics.