J. Mccall et al., Quenching of electrogenerated chemiluminescence by phenols, hydroquinones,catechols, and benzoquinones, ANALYT CHEM, 71(13), 1999, pp. 2523-2527
Efficient quenching of RU(bpy)(3)(2+) (bpy = 2,2'-bipyridine) electrogenera
ted chemiluminescence has been observed in the presence of phenols, catecho
ls, hydroquinones, and benzoquinones. In most instances, quenching is obser
ved with 100-fold excess of quencher over Ru(bpy)(3)(2+), with complete que
nching observed between 1000- and 2000-fold excess. The mechanism of quench
ing is believed to involve energy transfer from the excited-state luminopho
re to benzoquinone. In the case of phenols, catechols, and hydroquinones, q
uenching is believed to occur via a benzoquinone derivative formed at the e
lectrode surface. Photoluminescence and UV-visible experiments coupled with
bulk electrolysis support the formation of benzoquinone products upon elec
trochemical oxidation.