CHEMILUMINESCENCE AND CATALYSIS OF DECOMPOSITION OF DISPIRO(DIADAMANTANE-1,2-DIOXETANE) IN SOLUTIONS OF LANTHANIDE PERCHLORATES .2. CHEMILUMINESCENCE OF EU-III, TB-III, AND PR-III

Chemiluminescence (CL) accompanying the decomposition of dispiro(diada mantane-1,2-dioxetane) (1) in acetonitrile solutions of Eu-III, Gd-III , Tb-III, Pr-III, and Ce-III perchlorates was studied. In the presence of Eu-III, Tb-III, and Pr-III ions, the chemiluminescence spectra con tain the luminescence bands of these ions. In the case of Gd-III and C e-III, the chemiluminescence is caused by deactivation of singlet-exci ted adamantanone (2). The excitation of the lanthanide ion depends on the existence of suitable energy levels at which intracomplex excitati on transfer from the (3)n,pi-state of ketone is possible. Chemilumine scence of 1 increases in solutions of Eu-III and Tb-III. The yields of CL and excitation of the lanthanide ions in the decomposition of 1 in the 1.Eu-III and 1.Tb-III complexes were determined: phi(Eu) = 0.013 +/-0.003 and phi(Tb) = 0.08 +/- 0.02. The fact that the efficiency for the population of the D-5(4)-level of Tb-III is higher than that for the D-5(1) and D-5(0)-levels of Eu-III is related to the difference in the energy gap between the triplet level of 2 and the excited levels of the lanthanides.