A new β-diketone complex with high color purity

• Published in: Journal of alloys and compounds 2006-07, Vol.418 (1), p.222-225
• Main Authors: Adati, R.D., Lima, S.A.M., Davolos, M.R., Jafelicci, M.
• Format: Article
• Language: English
• Subjects: Chemical synthesis; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic states; Exact sciences and technology; Light absorption; Luminescence; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Phosphor; Photoluminescence; Physics
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2005.10.062

In this work a new europium (III) complex with the following formula NH 4[Eu(bmdm) 4] was synthesized and characterized. The bmdm (butyl methoxy-dibenzoyl-methane) is a β-diketone molecule used as UV radiation absorber in sunscreen formulations. Coordination of this ligand to the Eu 3+ ion was confirmed by FT-IR, while the Raman spectrum suggests the presence of NH 4 + ions. The photoluminescence spectra present narrow lines arising from f–f intra-configurational transitions 5D 0– 7F 0,1,2,3,4, dominated by the hypersensitive 5D 0– 7F 2 transition. In the spectrum recorded at 77 K, all transitions split into 2 J + 1 lines suggesting that there is just one symmetry site around Eu 3+ ion. This symmetry is not centrosymmetric. The calculated intensity parameters are Ω 2 = 30.5 × 10 −20 cm 2 and Ω 4 = 5.91 × 10 −20 cm 2 for this complex. The CIE chromaticity coordinates ( x = 0.67 and y = 0.32) show a dominant wavelength of 615 nm. The color gamut achieved by this complex is a 100% in the CIE color space.