Synthesis, characterization and luminescence property of ternary rare earth complexes with azatriphenylenes as highly efficient sensitizers

A series of novel ternary rare earth complexes showing attractive luminescence properties were prepared with both neutral and anion ligands. Three azatriphenylene neutral ligands, 1,10-phenanthroline (phen), dipyrido [3,2-a: 2',3'-c] quinoxaline (dpq) and dipyrido 13,2-a: 2',3'-c] phenazine (dppz) were investigated systematically as sensitizers in the ternary rare earth complexes. Benzoate ions (BA(-)) and phenoxyacetate ions (POA(-)) were chosen as anion ligands. The compositions of these complexes were characterized by elemental analysis, rare earth coordination titration, molar conductivity measurement, IR spectroscopy, UV-vis absorption spectroscopy, (1)H NMR spectroscopy and TGA-DTA. The luminescence spectra, luminescence decay time and quantum efficiency of the complexes were also studied. The very strong luminescence intensities and rather long luminescence lifetimes (typically > 1.0 ms) were achieved for both Eu(3+) and Tb(3+) ternary complexes with phen and dpq as neutral ligands. Moreover, high quantum efficiencies (40-60%) were also obtained for Eu(3+) ternary complexes with phen and dpq as neutral ligands. (C) 2011 Elsevier B.V. All rights reserved.