In this thesis, the synthesis, characterization and applications of bimetallic Zintl clusters are explored. Zintl ions are polyanions of main group elements, primarily of the heavier elements of groups 14 and 15. The closo-Sn₉Ir(cod)3-, Sn₉Rh(cod)3-, and Pb₉Ir(cod)3- ions were prepared from precursors E₉4- (E = Sn, Pb), [M(cod)Cl]₂ (M = Rh, Ir) and 2,2,2-crypt in ethylenediamine/toluene solvent mixtures. The clusters were isolated and characterized via NMR spectroscopy and single-crystal X-ray diffraction studies. The closo-E₉Ir(cod)3- ions are the first known Ir(I) Zintl clusters and are examples of isostructural Sn/Pb homologues. All three complexes have 22-electron, bicapped square-antiprismatic structures and pseudo-C4v point symmetry with the Ir(cod) and Rh(cod) vertices attached in an η4 fashion. The Sn₉Rh(cod)3- ion possesses 119Sn NMR chemical shifts that are consistent with other known Sn₉4- transition metal derivatives. The structural studies and 1H and 13C NMR studies showed significant charge transfer to the cod ligands.

Novel Rh@Sn₁₂3- and Rh@Pb₁₂3- ions have been prepared and isolated in the solid state and the latter has been studied via 207Pb NMR. The ions are 26-electron clusters with near perfect icohsahedral Ih point symmetry. Additionally, Ir@Pb₁₂3- and the previously isolated Ir@Sn₁₂3- ion [Fässler et al. 2010, Chem. Eur. J.] were detected for the first time via 207Pb and 117Sn NMR, respectively. The 207Pb NMR of Rh@Pb₁₂3- and Ir@Pb₁₂3- have the most downfield 207Pb signals known to date, due to their σ-aromaticity.

The Sn₉4- and As₇3- Zintl ions were shown to be effective reducing agents in the synthesis of three novel transition metal complexes. The synthesis and crystallographic characterization of the novel [Rh₂H(PPh₂)₂(PPh₃)₃]-, Co₃(CO)₇3-, and [(C₃H₇N₂O)₃Ir₄(CO)₉]3- ions are reported for the first time and cannot be prepared using traditional reducing agents.

Controlled I₂ oxidations of preformed Zintl clusters Pt@Sn₉Pt(PPh₃)2- and Sn₉Ir(cod)3-, give well ordered tin-rich intermetallic nanoparticles of PtSn₄ and Ir₃Sn₇, respectively. The intermetallics were characterized by HR-TEM and XRD analysis. Both clusters have strong structural similarities with the final intermetallic, which appears to be an important factor in determining the phase of the resulting intermetallic nanoparticles. Despite the 1:9 (Ir:Sn) atomic ratio of the Sn₉Ir(cod)3- cluster, ordered Ir₃Sn₇ nanoparticles were formed instead of the compositionally-similar IrSn₄ phase. PtSn₄ is difficult to prepare by traditional methods and isolate due to the formation of other known Pt-Sn phases, such as PtSn, PtSn₂ and Pt₃Sn.