Energy transfer in the chemiluminescent system: Eu(II)/(III)-N-3(-)-H2O2

Chemiluminescence (CL) in the systems containing Eu(II), Eu(III)ions and hy drogen peroxide has been investigated. Earlier results show that these syst ems are sources of excited Eu(III) ions and singlet oxygen generated in the recombination reactions of the hydroxyl radicals which originate from hydr ogen peroxide decomposition. The excited Eu(III) ions undergo radiative dea ctivation. The addition of azide ions (N-3(-)) to the Eu(II)/(III)-H2O2 sys tem causes a significant increase in the chemiluminescence intensity and yi eld as a result of the energy transfer process from the dimers of singlet o xygen to Eu(III) ions. Taking into account the kinetic and spectral data ob tained from the systems studied, the scheme of processes is proposed, and t he quantum yield of chemiluminescence is estimated using the CL standard sy stem: luminol-haemin-H2O2. (C) 2001 Elsevier Science B.V. All rights reserv ed.