Abstract
The ECL emission from energy‐deficient mixed aromatic hydrocarbon (AHC) acceptor and tetrathiafulvalene (TTF) donor systems has been investigated in acetonitrile. Radical ion annihilation involving TTF radical cations and AHC radical anions was found to result entirely in acceptor fluorescence emission. Energy considerations show that AHC triplet formation followed by triplet‐triplet annihilation to produce the AHC first excited singlet state is the most probable mechanism for the observed ECL. The intermediacy of exciplexes in the ECL process was not observed experimentally.