New complexes of europium and gadolinium with 2,4,6-trichlorophenyl acetoacetate as ligand

Abstract The synthesis, characterization and photoluminescent properties of new europium complexes with 2,4,6-trichlorophenyl acetoacetate (TCA) and 3-amino-2-carboxypyridine-N-oxide (picNO) ligands have been investigated. Results of the characterization are in agreement with the molecular formula proposed. The emission spectra at 77 K of the [Eu(TCA) 2 (H 2 O) 5 ]OH and [Eu(TCA) 2 (picNO)(H 2 O) 2 ]OH complexes, excited at 333 nm, display the typical transitions of the europium ion, 5 D 0 → 7 F J ( J = 0–4), indicating an efficient luminescence sensitization of this ion by the TCA ligand. The satisfactory agreement between experimental and theoretical absorption spectra of the organic part of the complexes suggests that the geometries optimized by the Sparkle model are correct. These results suggest these complexes as potential candidates as useful markers.