Synthesis, Crystal Structure, and Luminescent Properties of 2-(2,2,2-Trifluoroethyl)-1-indone Lanthanide Complexes

A new β-diketone, 2-(2,2,2-trifluoroethyl)-1-indone
(TFI),
which contains a trifluorinated alkyl group and a rigid indone group,
has been designed and employed for the synthesis of two series of
new TFI lanthanide complexes with a general formula [Ln­(TFI)3L] [Ln = Eu, L = (H2O)2 (1), bpy
(2), and phen (3); Ln = Sm, L = (H2O)2 (4), bpy (5), and phen (6); bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline].
X-ray crystallographic analysis reveals that complexes 1–6 are mononuclear, with the central Ln3+ ion eight-coordinated by six oxygen atoms furnished by three TFI
ligands and two O/N atoms from ancillary ligand(s). The room-temperature
photoluminescence (PL) spectra of complexes 1–6 show strong characteristic emissions of the corresponding
Eu3+ and Sm3+ ions, and the substitution of
the solvent molecules by bidentate nitrogen ligands essentially enhances
the luminescence quantum yields and lifetimes of the complexes.