Electrochemiluminescence in low ionic strength solutions of 1,2-dimethoxyethane

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 396; no. 1; pp. 85 - 95
• Main Authors: Maness, Karolyn M., Wightman, R. Mark
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 31.10.1995; Elsevier Science
• Subjects: 1,2-Dimethoxyethane; Chemistry; Concentration effects; Electrochemiluminescence; Electrochemistry; Exact sciences and technology; General and physical chemistry; Photoelectrochemistry. Electrochemiluminescence; Concentration effects; 1,2-Dimethoxyethane; Electrochemiluminescence; Photoelectrochemistry; Gibbs free energy; Electrical properties; Electrolyte solution; Ionic conductivity; Transition metal; Polycyclic aromatic compound; Experimental study; Condensed benzenic compound; Ketone; Steady state; Organic solvent; Platinum; Concentration effect; Bicyclic compound; Microelectrode; Thermodynamic properties; Electrochemical reaction; Organic compounds; Disk electrode
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/0022-0728(95)03926-8

Steady-state electrochemiluminescence (ECL) arising from ion annihilation reactions was examined at a double-band microelectrode in 1,2-dimethoxyethane (DME) as a function of electrolyte concentration for the following reactions: the 9,10-diphenylanthracene (DPA) radical cation with the DPA, benzil and 2-naphthyl phenyl ketone (NPK) radical anions, and the rubrene radical cation with the rubrene radical anion. The ECL efficiency of all systems was found to increase as the added electrolyte concentration was decreased from 100 to 0.1 mM. These increases were found to correlate with changes in Δ E 1/2 attributed to ion-pairing of the radical ions with their electrolyte counter-ions. For the energy-sufficient ECL reaction of DPA in DME, the increase in the Gibbs energy available for reaction as the electrolyte concentration was lowered produced an ECL efficiency approaching the theoretical limit of 25%.