Isolation and Reactivity of Reduced Rare-Earth Metal Homoleptic and Heteroleptic Complexes Featuring Cyclopentadienyl Ligands

This dissertation focuses on the expansion of ligand sets available to isolate new +2 ions of the rare earth metals, i.e., Sc, Y, and the lanthanides. In addition to their isolation, their reactivity and physical properties have also been investigated. Chapter 1 describes the basis of this dissertation research, i.e., the initial isolation of new Ln(II) ions using the (C5H4SiMe3)33− ligand set and the characterization of these new Ln2+ ions. Chapter 2 describes the use of the (C5Me4H)33− ligand set to isolate a new series of Ln2+ complexes and compares their properties to the (C5H4SiMe3)33− complexes. In the (C5H4SiMe3)33− ligand set, Dy adopts a 4f95d1 electron configuration while in the (C5Me4H)33− ligand set, Dy adopts a 4f10 electron configuration. Chapter 3 describes efforts to isolate the first C5Me5 complex of a new Ln2+ ion in heteroleptic Y2+ complexes of the form, [CpX2Y(NR2)]1−, where CpX = C5Me5 and C5Me4H, and study their properties. Chapter 4 describes the reactivity and reductive chemistry of rare earth metal allylcomplexes with benzoxazole. Appendix A describes the reactivity of the [(C5Me4H)3Ln]1− complexes for Ln = La and Ce with tert-butyl isocyanide including EPR spectroscopy. Appendix B describes efforts to synthesize and reduce other heteroleptic rare earth metal complexes by investigating the dynamic between ligand choice and the identity of the rare earth metal