Synthesis of a low-coordinate erbium (III) β-diketonate complex assembled by opto-electronically active 1,3-diphenyl-1,3-propanedione and triphenylphosphine oxide ligands

Abstract

A novel Er(III) β-diketonate complex, tris(dibenzoylmethanate)mono(triphenylphosphine oxide) erbium(III) or [Er(dbm)3(tppo)] was synthesised with dbm as a main sensitizer and tppo as a synergic ligand. The single crystal X-ray analysis reveals that the crystal structure of the complex is a triclinic centrosymmetric where Er(III) ion is coordinated to seven oxygen atoms; one O-atom from one tppo and six O-atoms from three dbm ligands. Shape-measure criterion measurements show that the complex possesses a distorted monocapped octahedron geometry, which facilitates the radiative transitions that is an indicative of efficient energy transfer from coordinated ligands to Er ion. The crystal structure is stabilised by the π–π stacking and CH/π interactions which lead to its high photo- and thermal stabilities. The complex was doped into a polymer matrix and the resulted material shows an enhanced luminescence intensity as well as full width at half maximum (fwhm) which allow its possible use for optical-amplification applications. Finally, a single layered organic diode was fabricated to determine charge carrier mobility (μ0) inside the complex. For this purpose, the Mott–Gurney model was used which gave sizable μ0 of 3.39×10−9cm2/Vs (at <5V).