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Item Open Access 1,5 Diphosphadithiatetrazocines: synthesis, isomers, metal complexes and anions(1992) Edwards, Mark; Chivers, TristramItem Open Access 14-electron phosphonium alkylidenes in olefin metathesis: a synthetic and mechanistic study(2006) Romero Guadjardo, Patricio Eduardo; Piers, Warren E.Item Open Access 9-borafluorenes derivatives: chemical reduction and reactivity towards [Cp*A1(I)]4(2002) Romero Guadjardo, Patricio Eduardo; Piers, Warren E.Item Embargo A Comparative study of the radiolysis and photolysis (18490A) of hydrogen and deuterium chloride(1970) Jardine, Douglas K.; Armstrong, David A.Item Open Access A comparison of natural and synthetic clay minerals in the formation of pillar interlayered clay mineral catalysts(1996) Brandt, Kerstin Barbara; Kydd, Ronald A.Item Open Access A Computational Analysis of Supported and Unsupported Group 6 Transition Metal-Metal Bonds Based on the Natural Orbitals for Chemical Valence (NOCV) and the Extended Transition State (ETS) Techniques(2013-02-14) Ndambuki, Sylvester Wambua; Ziegler, TomA computational study has been carried out on the nature of the metal-metal bond of group 6 transition metal complexes based on the extended transition state (ETS) and natural orbitals for chemical valence (NOCV) methods. The analysis of the unsupported triple (M2L6) and quadruple (M2L2L´2; M=Cr,Mo,W; L,L´=π-acceptor/σ-donor ligands) metal-metal bonds demonstrated that the M-M bond strength follows the trend Cr<Item Open Access A Computational Study of 2 Electron Oxygen Reduction Reaction for Direct H2O2 Electrosynthesis(2024-05-01) Mostaghimi, Amir Hassan Bagherzadeh; Van Humbeck, Jeffrey; Trudel, Simon; Md kibriaHydrogen peroxide has been identified as one of the 100 most important chemicals for global industry. This environmentally friendly oxidizing agent has many uses in several industrial sectors, including textiles, chemical synthesis, water treatment, and disinfection. The current industrial method for mass production of H2O2 is the anthraquinone process, which is energy-intensive. Additionally, environmental and transportation concerns involving the anthraquinone process make it an unsustainable method for H2O2 production. Therefore, direct electrochemical synthesis of H2O2 via 2e− oxygen reduction reaction (ORR) has gained attention from researchers in this field. This thesis is focused on developing selective electrocatalytic materials for 2e−ORR. This research employed computational chemistry theories and methods, namely Density Functional Theory (DFT), to study the electrochemical synthesis of H2O2 on carbon-based and metal electrocatalysts. DFT-based calculations have been carried out to estimate adsorption energy and formation energy, as well as Bader charge analysis and Density of States (DoS) calculations to gain insight into the thermodynamics of the reaction and the nature of the active sites. In Chapter 3, partially oxidized Pd carbon nanotubes have been investigated as a potential electrocatalyst for 2e− ORR. The results suggest the interaction between certain Pd clusters and the nearby oxygen-containing functional groups is key to reach high selectivity and low overpotential for 2e− ORR. Chapter 4 investigates an oxygen-functionalized ”holey graphene” structure as a low-cost and highly selective ORR catalyst. DFT calculations identified the presence of a mixture of functional groups that makes the neighboring carbons a suitable active site for selective H2O2 electrosynthesis. In the final section (chapter 5), we investigated a Au-based catalyst with a Pd surface layer. The thermodynamic analysis directly connected the number of Pd atoms and H2O2 selectivity. This thesis aims to support efforts to make the direct synthesis of H2O2 a more feasible process.Item Open Access A computational study of h2s adsorption on transition and noble metal surfaces(2009) Vartak, Swati; Ziegler, TomItem Open Access A density functional study on four-centre transition states and intermediates in organometallic chemistry(1993) Folga, Elzbieta; Ziegler, TomItem Open Access A developed metallomics method reveals the biochemical fate of Cd2+ and Hg species in erythrocyte lysate(2017) Gibson, Matthew; Gailer, Jürgen; Prenner, Elmar; Thurbide, Kevin; Osthoff, HansBioanalytical techniques that can be employed to obtain health-relevant information from biological fluids (i.e. erythrocytes) are urgently needed to gain new insight into the bioinorganic chemistry of non-essential metal species in the human body. To this end, a metallomics method was developed to probe the interaction of Cd2+, Hg2+, CH3Hg+ and thimerosal in the erythrocyte based on the direct analysis of erythrocyte lysate by size exclusion chromatography coupled on-line to an inductively coupled plasma atomic emission spectrometer (SEC-ICP-AES). This method development entailed systematic investigations into the sample preparation of the erythrocyte lysate (i.e. filtration to remove cell debris) as well into the identification of the ideal stationary phase and mobile phase. Filtering (0.45 μm pore-size Millex syringe-driven filers) and diluting (5-fold with corresponding buffer) resulted in the most consistent and reproducible results for the analysis of the erythrocyte lysate. A Superdex 75TM Increase 10/300 GL (300 x 10 mm I.D., 8.6 μm particle size) column that offers a fractionation range of 3 – 70 kDa was best suited for the separation of the major Cu, Fe and Zn metallospecies that are present in the erythrocyte lysate. 100 mM Tris(hydroxymethyl)-aminomethane (Tris) buffer (pH 7.4) was identified as the optimal mobile phase as it allowed for the separation of all the metallospecies of interest and gave the highest metal recovery of all the mobile phases (Zn: 95.8 ± 2.8% , Fe: 88.0 ± 7.2%). This developed metallomics method was subsequently employed to probe the comparative interaction of Cd2+, Hg2+, CH3Hg+ and thimerosal in erythrocyte lysate over a 6 h time period. The results that were obtained at time points ≥2 h revealed that ~85% of Cd2+ weakly interacted with hemoglobin (Hb), while ~13% eluted as (GS)xCd and ~2% bound to a ≥70 kDa Cd-binding protein. In contrast, ~6% of Hg2+ co-eluted with Hb at all time points, while ~94% eluted as (GS)xHg. The results for CH3Hg+ showed that ~5% of Hg co-eluted with Hb (constant over the 6 h time period), while for thimerosal (THI), this percentage gradually increased to 12% over the 6 h time period. The remaining Hg eluted as GS–HgCH3 and GS–HgCH2CH3, respectively. The co-elution of Hg with Hb – regardless of whether Hg2+, CH3Hg+ or THI was added – indicates that these interactions may adversely affect the function of Hb. The results demonstrate that the developed metallomics tool provided is ideally suited to obtain new insight into the bioinorganic chemistry and the toxicology of non-essential metal species within erythrocytes.Item Embargo A High pressure stopped-flow instrument: design and development(1983) Maxey, Suzan M. (Suzan Marie), 1954-; Swaddle, Thomas W.Item Open Access A kinetic, structural and compositional study of electrochemically formed hydrous ir oxide films(1997) Bock, Christina; Birss, Viola I.Item Open Access A md simulation study of self-assembly in metal-organic framework materials: a proof of principle(2011) Biswal, Debasmita; Kusalik, PeterItem Open Access A molecular modelling study of B-carboline ligands for the benzodiazepine receptor(1996) Spinney, Richard P.; Codding, Penelope W.Item Open Access A new, concise synthesis of the brassinosteroids castasterone and brassinolide(1992) Blazecka, Peter G.; Back, Thomas G.Item Open Access A novel protein footprinting platform: mass spectrometry of laser-initiated carbene reactions(2011) Jumper, Chanelle C.; Schriemer, David C.This work reports a protein labeling method using non-selective carbene reactions of sufficiently high efficiency to permit detection by mass spectrometric methods at the protein, peptide and residue level. The approach uses a diazirine-modified amino acid (L-2-amino-4,4' -azipentanoic acid, "photoleucine") as a label source, which is converted to a highly reactive carbene by pulsed laser photolysis at 355 nm. Labeling of model proteins and peptides was achieved with sensitivity to changes in protein topography brought about by conformational change and ligand binding. Labeling yield is independent of protein concentration over approximately two orders of magnitude, but is weakly dependent on the presence of other chromophores in a photon-limited apparatus. The current configuration required 2 minutes of irradiation for full reagent conversion, however it is shown that comparable yields can be achieved with a single high-energy laser pulse (>100 mJ/pulse, <10 nsec), offering a labeling method with high temporal resolution.Item Open Access A novel route to 4-quinolones and an enantioselective total synthesis of virantmycin(2004) Wulff, Jeremy Earle; Back, Thomas G.Item Embargo A Nuclear magnetic resonance study of arene metal tricarbonyl compounds(1966) Price, John Thomas; Sorensen, Theodore S.Item Open Access A Radiation chemical study of the reduction, oxidation and addition reactions of pterin and its reduced derivatives with free radicals(1987) Farahani, Mohsen; Armstrong, David A.Item Embargo A regulatory study of the extracellular thermostable alkaline serine protease from Malbranchea pulchella var. Sulfurea(1975) Dunham, Myrna Jean; Gaucher, G. Maurice