Abstract
Using several optical characterisation techniques, a detailed study assessing the ability of pyridine2,6-dicarboxylic acid (dpa) and its 4-mono- and 3,4,5-trisubstituted analogues to sensitize emission from Pr3+, Nd3+, Gd3+, Dy3+ and Er3+ is presented. Sensitization of Ln3+ emission was demonstrated via the ligands in all complexes, excluding Gd3+, with emission covering the spectral range from 500nm to 1850nm obtained upon variation of the Ln3+ ion. From the study of the ligand-based photoluminescence obtained from Gd3+ complexes, and the relative ligand and Ln3+ emission obtained from the other complexes, the triplet and singlet state energies of the 3,5-dibromo substituted complexes (3,5-Br) are found to be ~2. 33eV and ~2. 89eV respectively. Subsequently using photoluminescence excitation spectra the triplet state energies of the dpa-based, chel-based and 4-CI based Ln3+ complexes are estimated to be ~2. 95eV, ~2. 75eV and ~2. 85eV respectively. The most efficient organolanthanide complex studied in this thesis was found to be that of Dy3+(chel)3 whilst the complexes of Er3+ were found to be the least efficient.