Modest effectiveness of carbostyril 124 as a sensitising chromophore in europium and terbium amide complexes based on 1,4,7,10-tetraazacyclododecane

A tetraazamacrocyclic ligand-containing four carboxamide coordinating arms has been prepared, which incorporates a 7-amino-4-methyl-2(1H)-quinolinone group (carbostyril 124). The europium and terbium complexes of this ligand have been isolated and sensitisation of the characteristic metal luminescence, following excitation of the organic chromophore, is observed. The results are contrasted with recent work using the same chromophore as sensitiser, Measurement of the luminescence quantum yields shows that sensitisation of terbium is more efficient than for europium although both the intensity and lifetime of the terbium emission are significantly reduced through a thermally activated back energy transfer process of deactivation which is operative at room temperature.