Terbium-fluorido cluster: an energy cage for photoluminescence

We report here that energy migration during luminescence can be extremely minimized by caging the fluorescent centers in a molecular cluster of [Tb 6 (μ 3 -F) 8 (piv) 10 (Hpiv) 4 DMF]· x DMF· y H 2 O 1 . Experimental and theoretical simulations reveal that bonding terbium with fluoride is the key to reducing the non-radiative multi-phonon relaxation processes, which is disparate to the common hydroxy-based lanthanide clusters. This work demonstrates that encapsulating terbium ions into a fluorido-bridged cage by organic ligands significantly enhances the luminescence quantum yield of such sub-nanosized materials.