Tetrakis erbium quinolinate complexes, electronic structure investigation

The electronic structures of three new synthesised tetrakis Erbium(III) quinolinate complexes (Na[ErQ(4)], Na[Er(Q57Br)(4)] and Na[Er(Q57I)(4)]) have been studied by means of photoemission and absorption spectroscopies and compared with corresponding experimental data of Tris(8-hydroxyquinolinate) Erbium(III) (ErQ(3)). Core level and valence band spectra of Na[ErQ(4)] are very similar to ErQ(3) ones apart from a slight modification in the O 1s core level. The fundamental physical parameters for optical device applications as ionization energy and optical gap are the same, corresponding to 5.2 eV and 2.9 eV respectively. For the other two molecules, the introduction of halogens (Br, I) in the ligands leads to a reduction of 0.2 eV for the optical gap and to an increase of 0.5 eV for the ionization energy with respect to ErQ(3). (C) 2014 Elsevier B. V. All rights reserved.