The synthesis, structural investigation, and photophysical properties of the complex [Tb(TTA)(2)(NO3) (TPPO)(2)] are reported. Unlike the analog tris-diketonate complex [Tb(TTA)(3)(TPPO)(2)], the new complex presents abnormally high luminescence intensity centered on the terbium ion. Our results clearly suggest a higher energy transfer efficiency from the TEA antenna ligand to the Tb(III) ion in the bis-diketonate complex compared with that in the tris-diketonate complex. A mechanism involving the increasing of triplet state energy when one TTA ligand is replaced by the NO3- group in the first coordination sphere is suggested and experimentally investigated to explain the anomalous luminescence properties of the new complex [Tb(TTA)(2)(NO3)(TPPO)(2)].
- energy transfer
- intramolecular energy-transfer