CHEMILUMINESCENCE OF SOME REACTIONS WITH MOLECULAR OXYGEN

— Many inorganic oxidation reactions involving a variety of oxidizing agents show chemiluminescence in the spectral region of 400–600 mp. Excited O 2 O 2 ‐associates are assumed to be the emitting molecules formed by bimolecular recombination of HO x O 2 ‐radicals. Oxidation of sodium sulfite with molecular oxygen in the presence of Cu‐ and Fe‐basic oxides shows chemiluminescence which originates from the reactions of the heavy metal complexes of OH‐ and O, H‐radicals with O 2 . The simplest way of producing a radical from O 2 is by the uptake of one electron. Suitable electron donors, such as hydro‐quinones and semiquinones, emit light if treated with oxygen. In certain organic solvents OH‐ can also act as electron donor. Its presence causes the formation of semiquinones from quinones in the absence of oxygen. The chemiluminescence which is observable upon treatment of alkaline dimethylsulfoxide, dioxane, pyridine‐water and alcohol‐water mixtures with oxygen is also attributable to electron transfer from OH‐ to O 2 .