This dissertation focuses of three different subjects. The first is the synthesis and characterization of heptacoordinate amidinate compounds. Heptacoordinate compounds are not common, but their structures have been studied. Group 4 amidinate compounds have been used as precursors in the CVD/ ALD processes. Ancillary ligands, such as amidinates, have been used to reduce air-sensitivity of complexes. Reactions of these complexes with water have been used to make metal oxide thin films.
In the first study, the complexes Zr[MeC(NiPr)2]3Cl [zirconium trisamidinate chloride], Hf[MeC(NiPr)2]3Cl [hafnium trisamidinate chloride], Zr[MeC(NiPr)2]3Me [zirconium trisamidinate methyl], Hf[MeC(NiPr)2]3Me [hafnium trisamidinate methyl], Zr[MeC(NiPr)2]3Et [zirconium trisamidinate ethyl], and Hf[MeC(NiPr)2]3Me [hafnium trisamidinate methyl] have been synthesized and characterized. The three amidinate ligands bind to the metal centers in a propeller-like fashion. This allows for Λ [lambda] and Δ [delta] enantiomers, which undergo fast exchange in solution. All of these complexes were also found to react with water in air to form Zr[MeC(NiPr)2]3OH [zirconium trisamidinate hydroxyl] or Hf[MeC(NiPr)2]3OH [hafnium trisamidinate hydroxyl] complexes.
The second portion of the dissertation focuses on the reactions of tungsten alkylidyne complexes with water. When W(≡CSiMe3)(CH2SiMe3)3 [tungsten neosilyl neosilylidyne] is reacted with water at room temperature, a tungsten trimer was formed and characterized via NMR spectroscopies and single-crystal X-ray diffraction. The reaction of a second complex, W(≡CtBu)(OtBu)3 [tungsten alkoxide neopentylidyne] with water was studied via NMR and mass spectrometries. While only one complex formed via the NMR-scale reactions, several more were identified using the DART ionizer to react W(≡CtBu)(OtBu)3 [tungsten alkoxide neopentylidyne] with water in air before being analyzed via MS.
The last subject focuses on the chemical shift trends of d0 [d0] metal complexes. Two trends have been identified and will be discussed in Part 5. The first trend, usually pertaining to hydride and alkyl complexes, is a downfield shift in the peaks of the a [alpha] atoms in first- and third-row metals from those of the second-row analogs. The first trend, which usually relates to alkylidene, alkylidyne, oxo, and fluoro complexes, is an upfield shift in the peaks of the a atoms in first- and third-row metals from those of the second-row analogs