ELECTROGENERATED CHEMILUMINESCENCE .60. SPECTROSCOPIC PROPERTIES AND ELECTROGENERATED CHEMILUMINESCENCE OF DECAPHENYLANTHRACENE AND OCTAPHENYLNAPHTHALENE

The spectroscopic properties and electrogenerated chemiluminescence (E CL) of octaphenylnaphthalene (OPN) and decaphenylanthracene (DecPA) ha ve been investigated. OPN displays a featureless fluorescence band at 424 nm and a fluorescence quantum yield of 0.06, while DecPA exhibits a structured fluorescence emission at 486 nm and a quantum yield of 0. 10. Cyclic voltammetric measurements reveal the formation of radical c ations and radical anions for both compounds, all of which appear rela tively stable, although OPN.+ decomposes at scan rates below 200 mV s( -1). The ECL spectrum of OPN, generated by sequential production of th e radical cation and radical anion of the compound at an electrode sur face, is broad and red-shifted by about 100 nm from the compound's flu orescence maximum. This indicates that the emission is not that of OPN , but of a decomposition product, presumably derived from the unstable radical cation. DecPA, however, displays very stable green ECL simila r in energy to its fluorescence spectrum.