We report the electrogenerated chemiluminescence (ECL) of 2-oxa-bicyclo[3.3.0]octa-4,8-diene-3,6dione (OBDD). Cyclic voltammetry at 100 mV/s shows two chemically reversible reduction waves but an irreversible oxidation wave. As opposed to the usual radical ion annihilation ECL, for this compound, ECL was observed in an acetonitrile solution just upon oxidation to the radical cation (D(+)) in the absence of any additional coreactant. This suggests that OBDD can produce the needed reducing species upon its oxidation, so ECL is probably generated by the reaction of D+ with a strongly-reducing free radical produced during OBDD electrooxidation. Production of CO(2) upon oxidation was found by bulk electrolysis and mass spectrometry. (C) 2009 Elsevier B.V. All rights reserved.