Synthesis, characterization, X-ray structure and photoluminescence properties of two Ce(III) complexes derived from pentadentate ligands

In this study, two new Ce(III) complexes [Ce(L-1)(NO3)(3)]center dot H2O and [Ce(L-2)(NO3)(3)]center dot H2O were synthesized and characterized by spectroscopic and analytical methods where L-1 and L-2 are pentadentate diimine ligands. Molecular structure of [Ce(L1)(NO3)(3)]center dot H2O was determined by single crystal X-ray diffraction study. The complex was found to crystallize as [Ce(L-1)(NO3)(3)] H2O. In the complex, the ligand L-1 coordinates to the Ce(III) ion with the N3O2 donor set and the Ce(III) ion sits within the cavity of acyclic ligand. The Ce(III) ion is 11-coordinated by three nitrogen atoms from the ligand and eight O atoms, six of which come from three nitrate ions, two from the ligand. In the structure of the complex, water molecules link molecules together to form a 3D hydrogen bond network. Thermal behavior of the Schiff base ligands and their Ce(III) complexes metal complexes were studied under nitrogen atmosphere in the temperature range of 20-800 degrees C. Thermal stability of the ligands increased upon complexation with Ce(III) ion. In the UV-Vis spectra of Ce(III) complexes, new absorption bands appeared at 340-450 nm and these new bands were attributed to metal-ligand (M-L) charge transitions. Photoluminescence properties of the ligands and their Ce(III) complexes were examined. (c) 2015 Elsevier B.V. All rights reserved.