The chemiluminescence of rare earth elements in sulfuric acid

It has been found that solutions of oxides of the rare earth elements (REE) in sulfuric acid exhibit chemiluminescence in the visible and ultraviolet ranges on interaction with the products of the electrolysis of H₂SO₄. Analysis of the luminescence fading curve shows that the process leading to deexcitation obeys a bimolecular law and its linear anamorphosis can be represented on coordinates I^–1/2 and t. The problem of the possible mechanism of the process involving the participation of S*O_4– ion-radicals is examined. A comparison is made with the known luminescence of the REEs, and possible explanations are put forward for the chemiluminescence of those REEs which are generally assumed to exhibit no luminescence.