Infrared-Emission Studies of Electronic-to-Vibrational Energy Transfer. III. Hg* + NO

Electronic‐to‐vibrational transfer has been observed in the system Hg^*(6³P_1,0)+NO. Both Hg^*(6³P₁) and Hg^*(6³P₀) have been found to be effective in bringing this about. A set of rate constants, k_v (or cross sections σ_v²) for electronic‐to‐vibrational transfer were derived according to various models from an observed set of steady‐state concentrations, N_v. The set of k_v bear a qualitative resemblance to those for Hg^*+CO (Part II). Hg^*+NO exhibits a significant but slowly diminishing probability for vibrational excitation into vibrational levels up to v=16 or 17, and an insignificant probability for vibrational excitation into higher levels than v=16–17, corresponding to ⅔ of the electronic energy converted into vibration. The qualitative similarity of these results to those obtained for Hg^*+CO suggests that a similar mechanism may be applicable here: ${\mathrm{Hg}}^{*}+\mathrm{NO}\to {\mathrm{HgNO}}^{*}\to \mathrm{HgNO}\to \mathrm{Hg}+{\mathrm{NO}}^{†}$ . However, there exists in the present system an alternative mechanism which would involve electronic‐to‐electronic transfer: ${\mathrm{Hg}}^{*}+\mathrm{NO}{\mathrm{(X}}^2\mathrm{\Pi )\to }\mathrm{Hg}+{\mathrm{NO}}^{*}{(}^4\mathrm{\Pi )}$ , followed by formation of NO^† in the ground X ²Π state by collisional deactivation of NO^*(⁴Π). The total cross section for electronic‐to‐vibrational transfer with Hg^*(6³P₁) as the donor was estimated to be (σ_vib²)₁=1–15 Ų, and that with Hg^*₀ as donor (σ_vib²)₀=0.05–1.0 Ų.