Luminescence and quantum yields of Eu3+ mixed complexes with 1-phenyl-1,3-butanedione and 1,10-phenanthroline or 1,10-phenanthroline-N-oxide

The solid-slate photo-physical properties (luminescence spectra. quantum yields, and decay times) of the complexes Ln(bzac)(3)L, (Ln = Eu+3 or Gd+3, bzac = 1-phenyl-1.3-butanedionr, L = water. 1,10-phenanthroline [phen] or 1,10-phenanthroline-NO [phenNO]) are investigated down to 77 K, and compared to those of the related complexes Eu(btfa)(3)L (btfa = 4,4,4-trifluoro-1-phenyl-1.3 butanedione). The observed quantum yields are enhanced by the phenNO molecules. This can be ascribed to a decrease in the non-radiative D-5(0) relaxation rates. Further, the quantum yields are larger for the btfa complexes, probably due to the presence of the electron withdrawing -CF3 groups.