Spectroscopic properties of the UOsub(2)(ACAC)sub(2)CHsub(2)Osub(n):Eusup(3+) (ACAC)=acetylacetonate ion)

Abstract

The uranyl ion possesses some properties, which makes it a potential component for a solar energy conversion system or biological application. It absorbs light in the shorter wavelength range of the solar spectrum, producing a relatively long-lived excited state. The excited state of uranyl ion has fluorescence peak at 520 nm, a property that makes it relatively convenient to investigate its reaction. The redox potential of the excited uranyl ion makes a powerful oxidizing agent. This may be of potential use in the photogeneration of oxygen, which is of great importance for the photocleavage of water. In this work, it is described the synthesis, characterization and spectroscopic study of the matrix UO2(ACAC)2.(H2O)n.(x%mol) Eu3+ (where x= 1, 3, 5 and 10). The compounds obtained were characterized by elementary analyses for determine the U6+ and Eu3+ concentrations, infrared spectra, thermal analyses, absorption in the UV-VIS range and luminescence spectra. The mainly bands in infrared spectra of the β-diketone observed in this work are νs C=O in 1540 cm-1 , νass C=O in 1540 cm-1 and νs C=C in 1577 cm-1. In the emission spectra, transitions of the triplet 3Πu 1 Σg+ was observed. The spectra of the uranyl matrix present behavior superimposed to doped 5% and 10% ones. The emission spectra of matrix doped with 1 and 3% showed a band shift to red region of spectrum light.