ELECTROCHEMICAL GENERATION OF THE EXCITED TICT STATES .2. EFFECT OF THE SUPPORTING ELECTROLYTE

The electrogenerated chemiluminescence (ECL) of 4-(9-anthryl)-N, N-3,5-tetramethylaniline (ATMA) was studied in acetonitrile electrolyte solutions using the triple-step method. In the electrogenerated spectra, only the twisted charge transfer (TICT) band has been observed. A Feldberg plot analysis indicates that the emitting species (excited TICT state) is formed directly by the electron transfer between a cation radical and an anion radical (S-route). A high emission efficiency (φeci = 0.011) and high yield of the excited state (φEs = 0.21) have been found in most of the electrolytes studied. However, in solutions containing perchlorates, φecl is markedly less, and decreases with increasing electrolyte concentration. The anomalous behaviour in the perchlorate solutions can be explained by the presence of protons produced during electrogeneration of the cation radical. © 1990.