Lanthanide imidodiphosphinate complexes Synthesis, structure and new aspects of electroluminescent properties

The lanthanide imidodiphosphinate complexes Ln(pip)(3) (Ln=Ce, Nd, Tb, Ho) were prepared from the corresponding Ln[N(SiMe(3))(2)](3) with [Ph(2)P(O)](2)NH in a quantitative yield. X-ray single structure analysis of Ce(pip)(3) has revealed that the lanthanide ion in these compounds coordinated by three bidentate [Ph(2)P(O)NP(O)Ph(2)](-) ligands and THF molecule. With respect to the organic light emitting diodes (OLED) application, the simple electroluminescent (EL) devices with a multilayer configuration ITO/TPD/Ln(pip)(3)/Yb, ITO/CBP/Ln(pip)(3)/Yb, ITO/TPD/Ln(pip)(3)/Alq(3)/Yb, ITO/TPD/Alq(3)/Ln(PiP)(3)/Yb were fabricated. It was found that the lanthanide imidodiphosphinate complexes possess the hole-blocking and electron-transporting ability and it was also observed the exciplex emission between these complexes and TPD. (C) 2009 Elsevier B.V. All rights reserved.