Crystal structure and luminescence spectra of ternary europium (III) complex [Eu (DBM)₃ (2,2′-BIPY)] (HDBM)

The crystal structure of europium tri(dibenzoylmethanate) complex with 2,2′-bipyridyl, C₇₀H₅₇N₂O₈Eu, has been determined by X-ray diffraction. The complex crystallizes in the triclinic space group P1. The cell dimensions are a =1.3375(1) nm, b=1.8591(2)nm, c=1.1339(3) nm, α=95.89(9)°, β=93.36(1)°, γ=85.48(1)° and Z=2. The total number of 5413 independent reflections with I>3σ(I) were used for the structure determination. The final calculated R value is 0.039. The central europium ion is octa-coordinated by six oxygen atoms and two nitrogen atoms forming a distorted square antiprism (SAP) with the local symmetry C₁. Using the Eu³⁺ ion as a luminescence probe, the high resolution excitation and emission spectra measured at 77K indicate only one Eu³⁺ site existing in the complex. The emission spectra of ⁵D₀→⁷F_j transition display the symmetry of the Eu³⁺ site is C₁.