Red light emitting europium complex functionalized with hydroxyketone

The luminescent europium was successfully synthesized by using 5-fluoro-2-hydroxyacetophenone (FHAP) hydroxyketone ligand. The composition and structure of the FHAP ligand and its complex were supported by various techniques such as IR, NMR and CHN elemental analysis. The UV-visible and photoluminescence spectroscopy were used to explain the sensitization or antenna effect of the organic ligand. On successful irradiation at 397 nm, the emission spectra of complex showed narrow characteristic peaks at 580 nm, 592 nm, 616 nm and 652 nm corresponding to the D0→F0, D0→F1, D0→F2, and D0→F3 electronic transition of the europium ion. Among these peaks, the electric dipole D0→F2 transition noticed the most intense peak which was hypersensitive to the site symmetry of europium ion and associated with the red luminescence of the complex. The CIE color coordinates of the complex fall in the red region of the chromaticity diagram. These results suggested that the light harvesting organic ligand FHAP absorbed the energy and transferred to the metal ion through sensitization process in an effective manner. On the basis of above results, we can be conclude that the complex possesses the candidature for light emitting materials and devices.