Previous work in the Rosenberg group showed that the half-sandwich complexes Ru(η5-indenyl)Cl(PR2H)(PPh3) (2i), where R = cyclohexyl (Cy), isopropyl (Pri), phenyl (Ph), para-tolyl (Tolp), react with the strong, bulky base KOBut to give highly reactive complexes Ru(η5-indenyl)(PR2)(PPh3) (6i) containing a ruthenium-phosphorus double bond, Ru=PR2. The reactions of these phosphido complexes 6i with some reagents, such as alkenes, carbon monoxide and dihydrogen, illustrate their rich and varied reactivity. To better understand the mechanisms of these reactions (whether the indenyl effect is necessary), synthesis of analogous secondary phosphine complexes containing the pentamethylcyclopentadienyl (Cp*) ligand, Ru(η5-Cp*)Cl(PPh3)(PR2H) (2) were prepared via ligand substitution at Ru(η5-Cp*)Cl(PPh3)2 (1). Cp* phosphido complexes Ru(η5-Cp*)(PR2)(PPh3) (6) were generated in situ and their reactivity was investigated to see if they behaved similarly to the indenyl complexes. Experimental evidence in this thesis suggests that variable hapticity is not necessary in our indenyl system. In addition, these experimental evidence highlights enhanced lability of ligand at the bulky Cp*Ru fragment and higher Bronsted basicity of the phosphido ligand (PR2-) in Cp* phosphido 6 relative to the indenyl analogues 6i. / Graduate / 2017-12-11 / 0488 / yangjin@uvic.ca

With the aim of finding alternative reaction media for the synthesis of subvalent main group and transition metal cluster compounds, traditionally made through solid state reactions or in superacidic media, different alternative reaction media have been explored in this work. Room-temperature ionic liquids are amongst the more unconventional reaction media used. The syntheses performed have been aimed at both anionic and cationic cluster and the main tools used for characterization have been different X-ray diffraction and spectroscopic techniques. Selected ionic liquids have along with dichloromethane been shown to work as alternative reaction media for room temperature synthesis of the Bi5[GaCl4]3 salt. The salt containing the subvalent naked bismuth polycation Bi5 3+ was isolated from reduction reactions of BiCl3 in Ga/GaCl3-dichloromethane respectively Ga/GaCl3-ioinc liquid media. Three different classes of ionic liquids based on phosphonium-, imidazolium- and pyrrolidinium- salts have been used in synthesis. Homopolyatomic clusters from the lighter Group 15 element arsenic have also been studied. Solutions from the oxidative and reductive reaction routes of arsenic and AsCl3 in Lewis acidic toluene media were studied by EXAFS spectroscopy. The results were evaluated using molecular dynamics simulations of arsenic clusters. A discussion on how the calculated As4 cluster model relates to the experimental data resulted from this study. In terms of homopolyatomic anionic clusters the [K+(2,2,2-crypt)]2Ge9 2- compound containing the naked Ge9 2- anionic cluster has been isolated. The crystallographic investigation of [K+(2,2,2-crypt)]2Ge9 2- shows Zintl cluster anion Ge9 2- to be tricapped trigonal-prismatic with a symmetry very close to D3h. A chemical bonding analysis reveals two local minima of D3h symmetry and the cluster interaction scheme to be based on highly delocalised bonding. Ligand supported transition metal clusters from tungsten and palladium have also been prepared. Reduction of WCl6 in a reaction mixture of ionic liquid and co-solvent toluene resulted in tritungsten decachloride; W3Cl10(MeCN)3, being formed. Furthermore, palladium sandwich compounds; [Pd2(Ga2Cl7)(C7H8)2], [Pd2(GaCl4)(C9H12)2]∙C9H12 and [Pd2(Ga2Cl7)(C6H5Cl)2] have been prepared using GaCl3-arene reaction media. / <p>QC 20121212</p>

This dissertation describes the design and synthesis of a series of half-sandwich amino acid complexes of the form), (aa = α-amino carboxylate), and their utility as asymmetric transfer hydrogenation catalysts of ketones. Variation of the metal center, the n-ring, and the aa was used to tune these systems for specific sets of ketones. Upon reaction with homochiral]s, the ligand environment in all of these complexes is pseudotetrahedral, leading to stereogenic metal ions (SM, RM). The addition of another stereogenic center from the amino acid ligand (the carbon, RC or SC;glycine) gives rise to two pairs of diastereomeric complexes. / Ph. D.

This dissertation describes the synthesis and antimicrobial use of a series of half-sandwich Ir(III), Rh(III), Co(III) amino acid and ethylenediamine complexes. This investigation focuses on the formulation (ηn-arene)M(L)X, (L = ethylenediamine or α-amino carboxylate), (M= Ir, Rh, Ru, Co). Arene, Ligand and metal center variations were designed to tailor antimicrobial activity specific for each organism studied (Staphylococcus aureus or Mycobacteria). Each of the D/L-amino acids formed a diasteromeric complex with chiral centers on both the metal center and amino acid ligand. The unique chirality of each center elicits different antimicrobial activity against the Mycobacteria studied. The metal center (M), arene ligand (ηn-arene), and amino acid (aa), were changed independently and studied for the antimicrobial activity. In a similar fashion, each of the complexes modified with ethylenediamine and diamine derivatives were studied for their antimicrobial activity against S.aureus. All complexes were synthesized,characterized by nuclear magnetic resonance (NMR), high-resolution mass spectroscopy (HRMS), single-crystal X-ray diffraction, and elemental analysis. During the course of this work it was found that the amino acid complexes with all metal centers were specific for antimicrobial activity against all types of Mycobacteria, while the diamine derivatives were active against different strains of S.aureus. Acitvity was measured to be as low as 2 ug/mL respectively depending on the complex used. A structure activity relationship was developed to determine what combinations of ligand, metal and arene were necessary to achieve the highest antimicrobial activity. The optimal arene R-chain length for CpR was determined to be R=hexyl for all complexes studied. The most active amino acidcomplex was determined to be that of L-phenylglycine for Mycobacteria, the cis-1,2-diaminocyclohexane complex is the most active ligand against S.aureus. Each metal center had similar activity levels. Toxicological studies were performed to test their viablity to be used in mammalian systems. The complexes with the highest activity were studied against several mammailan cell lines and revealed that mammailan cells were undergoing normal cellular processes at up to 40 times the minimal inhibitory concentration (MIC). A study of the MOA or mechanism of action revealed the ability of the amino acid complexes to affect the peptidyl transferase region on the 23s ribosomal subunit of M.smegmatis. This was accomplished by isolating resistant strains of M.smegmatis towards the most effective complex (Cp*hexyl)Ir(L-phenylglycine)-Cl. Cross drug resistance of these mutants was shown with clarithromycin. The DNA of the 23s ribosomal subunit was sequenced revealing a deletion/insertion mutation within domain V (bases 2057-2058). / Ph. D.

No description available.