Deactivation of Hg (63P1) by CO and N2

Abstract

Atoms of Hg(6³P₀) produced by collisions between Hg(6³P₁) and either N₂ or CO were detected by measuring the electrons ejected from a silver surface. From the pressure dependence of this effect, it was shown that the quenching of Hg(6³P₁) to Hg(6³P₀) by collision with CO occurs at about the same rate as with N₂. Since CO is 20 times more efficient than N₂ in the quenching of 2537 A fluorescence, the process $$[\mathrm{Hg}{\text{(6}}^3{P}_1\mathrm{)+}\mathrm{CO}\to \mathrm{Hg}{\text{(6}}^1{S}_0\mathrm{)+}{\mathrm{CO}}^{*}]$$ must be much faster than the corresponding reaction with N₂. A possible explanation of this effect is the intermediate formation of HgCO^*, which dissociates to Hg(6¹S₀) and vibrationally excited CO(v=20). This could account for the fact that H₂CO and (HCO)₂ are formed in the Hg photosensitized reaction of H₂ and CO and not in the electric discharge experiments of H atoms reacting with ground state CO.