https://doi.org/10.1351/goldbook.S05695
Oxygen molecule (dioxygen), O2, in an excited ). The two and (the latter with the higher energy).
singlet state
. The ground state
of O2 is a triplet (metastable
singlet states derived from the ground-state configuration are Notes:
- Use of the term singlet oxygen alone, without mention of the chemical species is discouraged since it can also refer to an oxygen atom in a
orexcited state. The oxygen atomground stateis a triplet state and the and states are also derived from the ground-state configuration. - Triplet statequenchingby triplet dioxygen (i.e., a process ofphotosensitization) is the most common procedure for the production of singlet molecular dioxygen in solution. For many chemical species, the efficiency with which thetriplet stateis quenched by triplet dioxygen and, independently, the efficiency with singlet molecular dioxygen is produced, is controlled by the spin-statistical factor.