EN
Two different procedures for the study of the quenching of excited states by lanthanide complex ions on the surface of micelles are considered. In the first, excited Tb(pdc)_{3}^{3-} (pdc = pyridine 2,6-dicarboxylate) complex ions are held in close proximity to other Ln(pdc)_{3}^{3-} ions on the surface of cetyl trimethyl ammonium micelles. Efficient energy transfer is observed by the electric dipole-electric dipole mechanism with a mean interaction distance only slightly greater than that which exists in the crystalline complexes. In the second, the excited state of Tb(pdc)_{3}^{3-} is depopulated by energy transfer to the coexcited lowest excited triplet state of phenanthrene which is thereby excited to the second triplet state.