Highly preorganized ligands such as 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) have typically shown much higher formation constants than their straight chain analogs. In particular, PDA has shown selectivity for large metal ions (approximately 1.0Å) with high charge. An important application of this ligand is in the nuclear waste industry, which has a demand for ligands which will complex selectively with Pu(IV) and Am(III) in order to remove these valuable and dangerous metal ions from wastes. UV-Vis spectrophotometry as well as X-ray crystalography were used to study the ability of PDA to selectively complex Th(IV), UO2(VI), Lu(III) and Ce(IV) over common metal ion contaminants such as Fe(III) and Al(III). These lanthanides and actinides were examined as a precursor to further studies of PDA complexes with Am(III) and Pu(IV).