Vibrational-mode-specific energy consumption. Translational and vibrational state dependence of the Ba + N2O (v1, v2, v3)→ BaO*+ N2 reaction

Abstract

The excitation functions _CL(E, T_v) for forming chemiluminescent (CL) products in the (Ba + N₂O) reaction is found to depend sensitively on N₂O vibrational temperature T_v. In a second experiment thermal rate constants for CL production k_CL, and for Ba beam attenuation k_T, were measured as functions of N₂O temperature, and activation energies were obtained. Analysis shows that v₂-bending acts as promoting mode, and participation by v₁(N–O stretch) is highly likely. Promotion by v₂ is consistent with the initial formation of an ion pair Ba⁺N₂O^–. Rearrangement of this intermediate to BaO*(A′¹Π) products, believed to be the CL emitter, is adiabatically allowed.