Abstract The adduct Eu(btfa) 3 bipy ( btfa = 4,4,4-trifluoro-1-phenyl-2,4-butanedione, bipy = 2,2'-bipyridine) was synthesized and its X-ray structure was determined. The UV absorption spectra of the ligands and complex were obtained in ethanolic solution. The luminescence spectrum of the solid complex at 77 K suggests the existence of a single emitting site, in agreement to the X-ray structure. The electronic spectrum of the complex was fairly predicted via the INDO/S-CI method, using either of two input geometries: one from the X-ray data and another obtained by the SMLC/AM1 method. Finally, we have also observed that the fluorinated β-diketonates of Eu(III) adducts, like Eu(btfa) 3 bipy, are more luminescent than the analogous nonfluorinated ones.