FLUORESCEIN AND EOSIN AS SENSITIZING CHROMOPHORES IN NEAR-INFRARED LUMINESCENT YTTERBIUM(III), NEODYMIUM(III) AND ERBIUM(III) CHELATES

Near-infrared luminescent ytterbium(III), neodymium(III) and erbium(II I) chelates containing organic chromophores derived from fluorescein a nd eosin have been synthesized and studied spectroscopically. The comp lexes can be efficiently excited with visible light and show intense l anthanide luminescence at low concentrations (approximate to 10(-6) mo l l(-1))in D2O as a result of energy transfer from the dye moiety to t he ran earth ion. Quenching of the luminescence of the complexes by mo lecular oxygen reveals information on the rate of energy transfer from the ''antenna'' chromophore to the lanthanide ion. (C) 1997 Elsevier Science B.V.