Electrochemiluminescence of Tris(2,2′‐bipyridine)ruthenium with Various Co‐reactants under Ultrasound Irradiation

Abstract

Electrochemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium, Ru(bpy)

Electrochemiluminescence of Tris(2,2′-bipyridyl)ruthenium(II) with Ascorbic Acid and Dehydroascorbic Acid in Aqueous and Non-aqueous Solutions

“…10,11 The ECL intensity was strongly dependent on the pH of the solution, and the signal could not be observed at acidic or neutral condition at previous report. 10 In MeCN, oxidation of H2A and Ru(bpy)3 2+ was observed around +1.0 and +1.2 V, respectively (the solid line in Fig.…”

“…It suggested that ECL quenched by H2A as was proposed in our previous studies. 10,11 The generated *Ru(bpy)3 2+ at the electrode surface could be quenched by charge transfer between *Ru(bpy)3 2+ and H2A as suggested below, Figure 4(A) presents the electrochemical behavior of 0.50 mM DHA in MeCN. Although DHA is easily hydrolyzed to the corresponding hemiketal in aqueous media, it is very stable in dry MeCN.…”

“…[7][8][9] It will be oxidized to ascorbyl radical anion (A • -), an intermediate in weak basic conditions, and then to dehydroascorbic acid (DHA, oxidized form of vitamin C) via a two-electron and one-proton oxidation process. [10][11][12] Figure 1 shows the chemical structures of H2A, its monoanion (HA -) and its possible oxidative products. In recent years, vitamin C has been studied as a coreactant in Ru(bpy)3 2+ ECL systems.…”

“…Controlled potential and ECL measurements were performed as described. [10][11][12] Emission from the electrode surface was measured with a photomultiplier tube (H7732-10, Hamamatsu Photonics, Shizuoka, Japan) placed opposite the working electrode. ECL spectra were measured with a spectro fluorophotometer (USB2000, Ocean Optics, FL, USA) in continuous potential step mode.…”

“…[10][11][12] However, no experimental evidence was provided in order to produce the stable A • -species at electrode surface, the electrochemical reduction of DHA in MeCN was performed. Figure 3 shows the ECL profile for 0.50 mM Ru(bpy)3 2+ using H2A and DHA as coreactants in MeCN obtained by double pulse potential step measurement.…”