A fluorescence emission, FT-IR and UV-VIS absorption study of the some uranium (VI) Schiff bases complexes

The capacity of metallic ions to form complexes depends on the electric charge and its mass and on the ligands nature. In this study we followed the coordination capacity of the uranyl ion (UO22+) with a series of Schiff bases. The Schiff bases have been obtained through the condensation of some salicylic aldehyde derivates with a series of diamines. As a result of the reaction between these substances and the uranyl ions the mono-, bi-, or poly-nuclear complexes, depend on the nature of the ligands. The forming of the complexes is highlighted through ultraviolet-visible, Fourier transform infrared (IR), and fluorescence spectroscopy. In the IR studies the forming of the complexes is highlighted by the apparition of a new band at approximately 920 cm(-1), characteristic to the O=U=O group. Also modifications of valence vibrations appear characteristic to the azomethinic groups, nu(C=N), and the apparition of some new bands in the 300-500 cm(-1) domain, characteristic to forming of some new bonds U-O and U-N. The formed complexes represent tetragonal bipyramidal geometry. The study of the capacity coordination of uranyl ions is important in determining, dozing and precipitin of the ions in diverse used waters.