Mono- and dinuclear europium(III) complexes with thenoyltrifluoroacetone and 1,10-phenanthroline-5,6-dione

The N , N ′-coordinated mononuclear complex Eu(TTA) 3 (pdn), prepared by treating 1,10-phenanthroline-5,6-dione (pdn) with Eu(TTA) 3 (H 2 O) 2 (HTTA = 2-thenoyltrifluoroacetone), may be used as a benzoquinone-like ligand through the oxygen donor atoms in reaction with an additional Eu(TTA) 3 (H 2 O) 2 precursor to give the dinuclear complex Eu 2 (TTA) 6 (pdn). Both the mono- and dinuclear complexes were characterized by elemental analysis, IR, TG, MS, and 1 H NMR spectra. The results indicated that they both exhibited a characteristic red emission peak at 616 nm, corresponding to the 5 D 0 → 7 F 2 transition of Eu(III) ions under UV excitation. Compared with the mononuclear complex, the dinuclear complex presented better thermal stability and stronger luminescence, which makes it a promising light-conversion molecular device. Graphical abstract .