Electrochemiluminescence of copper(I) bis(2,9-dimethyl-1,10-phenanthroline)

The electrochemical and electrochemiluminescence (ECL) properties of Cu[dmp ](2)(+) (dmp = 2,9-dimethyl-1,10-phenanthroline)have been investigated. ECL has been observed for Cu(dmp)(2)(+) in aqueous, nonaqueous, and mixed solv ent solutions using tri-n-propylamine as an oxidative-reductive coreactant. The ECL intensity peaks at potential corresponding to oxidation of both th e coreactant and Cu(dmp)(2)(+). The peak potential corresponding to maximum ECL emission is similar to 500 mV more anodic than corresponding oxidative peak potentials, indicating that the ECL emission may be due to the format ion of either the *Cu(dmp)(2)(+) metal-to-ligand charge-transfer excited st ate or an excited-state product of Cu(dmp)(2)(+) oxidation. ECL efficiencie s (phi (ecl) = photons generated per redox event) are solvent-dependent (ph i (ecl) (CH3CN) > phi (ecl) (50:50 (v/v) CH3CN:H2O) > phi (ecl) (H2O)) and correspond fairly wen with photoluminescence efficiencies. Increased ECL ef ficiencies (greater than or equal to 50-fold) are observed in the presence of the nonionic surfactant Triton X-100.