A1 Journal article – refereed
Hot electron-induced electrogenerated chemiluminescence of rare earth(III) chelates at oxide-covered aluminum electrodes
List of Authors: Kulmala S, Ala-Kleme T, Latva M, Loikas K, Takalo H
Publisher: PLENUM PUBL CORP
Publication year: 1998
Journal: Journal of Fluorescence
Journal name in source: JOURNAL OF FLUORESCENCE
Journal acronym: J FLUORESC
Volume number: 8
Issue number: 1
ISSN: 1053-0509
Abstract
Aromatic Gd(III) and Y(III) chelates produce ligand-centered emissions during cathodic pulse polarization of oxide-covered aluminum electrodes, while the corresponding Tb(III) chelates produce metal-centered D-5(4) --> F-7(J) emissions. It was observed that a redox-inert paramagnetic heavy lanthanoid ion, Gd(III), seems to enhance strongly intersystem crossing in the excited ligand and direct the deexcitation toward a triplet-state emission, while a lighter diamagnetic Y(III) ion directs the photophysical processes toward a singlet-state emission of the ligand. The luminescence lifetime of Y(III) chelates was too short to be measured with our apparatus, but the luminescence lifetime of Gd(III) chelates was between 20 and 70 mu s. The mechanisms of the ECL processes are discussed in detail.