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 solvent solutions using tri-n-propylamine as an oxidative-reductive coreactant. The ECL intensity peaks at potential corresponding to oxidation of both the coreactant and Cu(dmp)2+. The peak potential corresponding to maximum ECL emission is ∼500 mV more anodic than corresponding oxidative peak potentials, indicating that the ECL emission may be due to the formation of either the *Cu(dmp)2+ metal-to-ligand charge-transfer excited state or an excited-state product of Cu(dmp)2+ oxidation. ECL efficiencies (φecl = photons generated per redox event) are solvent-dependent (φecl (CH3CN) > φecl (50:50 (v/v) CH3CN:H2O) > φecl (H2O)) and correspond fairly well with photoluminescence efficiencies. Increased ECL efficiencies (≥50-fold) are observed in the presence of the nonionic surfactant Triton X-100.
metal to ligand charge transfer, solution chemistry, solvents, oxidation, excited states
McCall, Jeff, David Bruce, Scott Workman, Christopher Cole, and Mark M. Richter. "Electrochemiluminescence of copper (I) bis (2, 9-dimethyl-1, 10-phenanthroline)." Analytical chemistry 73, no. 19 (2001): 4617-4620.