Oxygen molecules break down to nascent oxygen atoms in the ozone layer & then form an equilibrium with the ozone molecule. I guess exposing oxygen to the right frequency radiation can break it down into its constituent oxygen atoms.

PS: exposing any type of molecule to the right frequency of radiation can break it down into constituent atoms. But even then you cannot eliminate the weak forces (like vander waal forces or London forces) so the constituent atoms will still try to group together to form some other type of molecule & will be in equilibrium with that molecule.