Free energy dependence on tris(2,2′-bipyridine)ruthenium(II) electrochemiluminescence efficiency

The electrogenerated chemiluminescence (ECL) of Ru(bypy)32+ with four series of electroactive organic compounds in 0.1 M (C2H5)4NPF6 acetonitrile solutions has been studied using a triple-potential-step technique. The yields of the formation of the excited ∗Ru(bypy)32+ ion produced by the electron-transfer reaction of Ru(bypy)3+ with aromatic amine or 2,3,7,8-tetramehoxythianthrene radical cations and by the reaction of Ru(bypy)33+ with quinone or nitroaromatic radical anions and N-methylpyridinium radicals have been determined. The obtained yields for the excited ∗Ru(bypy)32+ ion formation have been compared with the predicted ones according to the oxidative or reductive ∗Ru(bypy)32+ quenching data.