Formation and Stabilization of Ground and Excited State Singlet O2 upon Recombination of 3P Oxygen on Amorphous Solid Water
Abstract
The recombination dynamics of 3P oxygen atoms on cold amorphous solid water to form triplet and singlet molecular oxygen (O2) is followed under conditions representative for cold clouds. It is found that both, formation of ground state (X 3 g-) O2 and molecular oxygen in the two lowest singlet states (a 1g and b 1g+) is possible and that the species can stabilize. The relative proportions of the species is approximately 1:1:1. These results also agree qualitatively with a kinetic model based on simplified wavepacket simulations. As the chemical reactivity of triplet and singlet O2 is different it is likely that substantial amounts of a 1g and b 1g+ oxygen influences the chemical evolution of cold clouds.
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