Syntheses and characterization of anhydrous lanthanide complexes containing tetradentate Schiff base ligands

A common theme in contemporary f-element chemistry is the synthesis and characterization of alternative (i.e., non-cyclopentadienyl) ligand scaffolds which maintain low coordination numbers. This dissertation will report the synthesis and characterization of tetradentate Schiff bases that are easily synthesized, inexpensive, contain periphery that can be easily tailored, and are sterochemically rigid, for metallation with various large Ln3+ ions. As is seen the literature, isolating monomeric, low-coordination number, anhydrous, f-element complexes is extremely difficult and arduous. This dissertation will report how to overcome this difficulty, and describe the preparation and complete characterization of mono-, and di-, tri-, and tetranuclear lanthanide Schiff base complexes selectively synthesized by properly matching metal ionic radius and steric features of the ligands bound to it. The conditions (e.g., solvent, ligand sterics, and metal size) required to promote the desired complexes will be discussed and emphasized. Additionally, we sought, and succeeded, in yielding more accessible rare earth ions for a variety of substrates by tuning the utilized Schiff base to contain decreased “frontal” steric bulk. Finally, to prove that this ligand framework is both stable and versatile for future reactions, the mononuclear amido complexes were reacted with alcohols of varying sizes and found that this system can undergo apical ligand exchange reactions without ketoiminato degradation, replacement, or protonolysis