Physical Sciences and Mathematics Commons^™

Adsorbed Gas Behaviour And Guest-Host Interactions In Ultramicroporous Metal-Organic Frameworks, Bligh Desveaux

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are a class of porous materials that have attracted much attention due to their large surface areas, high tunability and their high selectivity for gas adsorption applications. In this work, solid-state nuclear magnetic resonance (SSNMR) experiments and single crystal X-ray diffraction (SCXRD) experiments are used to investigate carbon dioxide adsorption within the ultramicroporous MOFs SIFSIX-3-Zn (Chapter 2) and ZnAtzOx. (Chapter 3). Analysis finds that the CO₂ SIFSIX-3-Zn undergoes wobbling motions with a low temperature dependence, and in ZnAtzOx undergoes wobbling and hopping motions with a low temperature dependence. SCXRD is used to precisely determine the CO …

Fabrication And Modification Of Titania Nanotube Arrays For Harvesting Solar Energy And Drug Delivery Applications, Ahmed El Ruby Abdel Rahman Mohamed

Electronic Thesis and Dissertation Repository

The fast diminishing of fossil fuels in the near future, as well as the global warming caused by increasing greenhouse gases have motivated the urgent quest to develop advanced materials as cost-effective photoanodes for solar light harvesting and many other photocatalytic applications. Recently, titania nanotube arrays (TNTAs) fabricated by anodization process has attracted great interest due to their excellent properties such as: high surface area, vertically oriented, highly organized, one-dimensional, nanotubular structure, photoactivity, chemical stability and biocompatibility. This unique combination of excellent properties makes TNTAs an excellent photoanode for solar light harvesting. However, the relatively wide band gap energy of …

The Development Of Peptide Analogues As Potential Fluorescent And Pet Imaging Probes., Neha Sharma

Electronic Thesis and Dissertation Repository

Molecular imaging is a non-invasive way to diagnose disease. Molecular imaging probes consist of a targeting entity that has a high affinity for a biological target and a signaling source for external detection. Multimodality imaging combines the advantages of different imaging modalities, at the same time eliminating their shortcomings, thereby providing more accurate results. This thesis focuses on the development of novel dual PET/fluorescence imaging agents based on peptides as targeting entities.

Porphyrins are suitable for multimodality imaging applications due to their innate characteristics such as an ability to fluoresce and to coordinate metals. A gallium-protoporphyrin IX(PPIX)-ghrelin based analogue was …

Studying Metal-Organic Frameworks Via Solid-State Nmr: Gas Dynamics, Structure Determination, And Phase Transition, Yue Zhang

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are a class of microporous materials constructed from virtually endless combinations of metal centres and organic linkers. MOFs have attracted intense research interest in recent decades, since MOFs have outstanding properties such as extremely high surface area, tuneable pore topology, good stability, and many others. MOFs are also promising candidates for gas storage. In this work, solid-state NMR (SSNMR) spectroscopy has been investigated to study MOFs and their guest molecules, since SSNMR can provide information on the short-range environment about target nuclei and can also reveal the dynamics of guest molecules.

An introduction to MOFs and SSNMR …

Coordination And Organometallic Chemistry Of Novel Gallium Complexes: Synthesis, Reactivity And Spectroscopy, Jeremy L. Bourque

Electronic Thesis and Dissertation Repository

The work described in this thesis incorporates three main themes: the synthesis and reactivity of new coordination and organometallic gallium compounds, and the chemical state determination of molecular gallium complexes using XPS and XAS. The coordination chemistry of low valent gallium cations was explored using macrocyclic ethers as ligands. The experimental oxidation number, or chemical state, of newly synthesized low valent gallium cationic complexes was compared to known compounds to allow for the assessment of the electronic environment at gallium. The organometallic chemistry of gallium was examined using donor ligands to stabilize monomeric organogallium(III) compounds, demonstrating the ability to substitute …

Gamma-Radiation Induced Corrosion Of Alloy 800, Mojtaba Momeni

Electronic Thesis and Dissertation Repository

This thesis presents a newly developed mechanism and predictive model for the corrosion of Alloy 800. The Fe-Cr-Ni Alloy (Incoloy 800) is mainly used for steam generator (SG) tubing in CANDU and PWR reactors and is a candidate material for the proposed Canadian Supercritical Water Reactor (SCWR) in which it will be exposed to extreme conditions of high radiation flux and large temperature gradients. The influence of gamma radiation and water chemistry conditions on the corrosion behaviour of Alloy 800 are studied in this work. Ionizing radiation creates reducing (•e_aq^–, •H, •O₂^-) and oxidizing …

Dynamic Studies Of Guest Molecules In Metal-Organic Frameworks And Zeolites Via Solid-State Nuclear Magnetic Resonance, Bowei Wu

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are synthetic compounds with crystalline microporous structures, consisting of metal centres joined by organic linkers. Zeolites are a class of crystalline porous materials featuring negatively charged aluminosilicate frameworks and charge-balancing cations.

In this work, solid-state nuclear magnetic resonance (SSNMR) is used to probe guest molecule locations and dynamics in MOFs and zeolites, yielding detailed informations of guest motion within these porous materials

Chapter 2 describes SSNMR dynamic studies of ¹³CO₂, ¹³CO and C₂D₄ adsorption behaviour in the α - zinc formate MOF, [Zn₃(HCOO)₆], which were performed …

Determining The Reactivity And Oxidation Intermediates Of An Allylnickel (N-Heterocyclic Carbene) Chloride Complex, Scott W. E. Hendriks

Electronic Thesis and Dissertation Repository

The oxidation of C-H bonds to carbonyl functional groups using molecular oxygen (O₂) is a desirable process as O₂ is environmentally benign and inexpensive. However, oxidations that employ O₂ have lower product selectivity, making it industrially unappealing. The metal complexes NiCl(π-cinnamyl)(NHC) oxidize stoichiometrically with O₂ as the oxidant to selectively form the ketone and aldehyde products.

This thesis details the attempted catalysis with the NiCl(π-allyl)(NHC) complex and the stoichiometric reactivity of NiCl(π-allyl)(NHC) and NiCl(π-cinnamyl)(NHC) complexes upon O₂ exposure. An investigation of the intermediate and decomposition species of the NiCl(π-allyl)(NHC) complex was conducted. The complexes …

Investigations Into The Role Of Conformational Dynamics In Protein Function: Insights From Hydrogen/Deuterium Exchange-Mass Spectrometry, Courtney S. Fast

Electronic Thesis and Dissertation Repository

Deciphering protein structure and dynamics is a key prerequisite for understanding biological function. The current work aims to apply HDX-MS to improve the understanding of protein structure and dynamics for systems that remain challenging for other techniques. Following a general overview of the field (Chapter 1), Chapter 2 investigates the relationship between enzyme dynamics and catalysis. By conducting comparative HDX-MS measurements on rM1-PK during substrate turnover and in the resting state, catalytically active rM1-PK undergoes significant rigidification of the active site. However, virtually the same rigidification was seen upon exposing rM1-PK to substrate or product in the …

Fabrication And Characterization Of Cuins₂ And Cuinse₂ Light-Absorbing Thin Films For Use In Solar Cells, Amy R. Tapley

Electronic Thesis and Dissertation Repository

Solar energy is free and globally abundant and harnessed cost-effectively, it has the potential to be the world’s main source of energy. CuInGa(S,Se)₂ solar cells have a very high efficiency of 20 %. However, gallium is a rare and expensive element. We have decided to work on its alternative CuInSe₂ (CISe) and CuInS₂ (CIS) by removing gallium or both gallium and selenium. The p-type CISe or CIS light-absorbing semiconducting layer is crucial for this type of solar cell. Preparation methods for CIS and CISe films were developed to reduce the costs and enhance the photoelectrochemical efficiency.

The …

Synthesis Of N-Heterocycles From Donor Acceptor Cyclopropanes And Progress Towards Flinderole A, B, And C, Joanne E. Curiel Tejeda

Electronic Thesis and Dissertation Repository

The first chapter of this thesis describes two projects, one explores the novel reactivity of quaternary donor acceptor cyclopropanes and the second one involves progress toward the total synthesis of the flinderoles A, B, and C. The first project involves the Lewis acid catalyzed nucleophilic ring opening of quaternary donor acceptor cyclopropanes with indoline. It was found that the ring opening reaction worked well with either Sc(OTf)₃ or Yb(OTf)₃ as the Lewis acids. The ring opened products were also able to be converted into pyrroloindoles via a manganese (III) oxidative radical cyclization reaction. Cyclopropanes bearing alkynyl, vinyl, and …

Investigating Growth Of Metal-Organic Frameworks Via Atomic Force Microscopy, Zitong Wang

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are crystalline microporous materials that have drawn much attention in recent years for their promising applications in many fields of chemistry. To design MOFs with desired properties, a better understanding of how these frameworks self-assemble during crystallization is required. A useful technique for investigating the crystallization process of MOFs is atomic force microscopy (AFM). We have conducted AFM studies on four different MOFs: the gallium analog of the MIL-53 MOF, which exhibits the "breathing effect," and three Lead, Calcium and Cadmium-based MOFs that uses 4,4-sulfonyldibenzoate (SDB) as the organic ligand. Hydrothermal methods were used to prepare those …

Scanning Electrochemical Microscopy Of Human Bladder Cancer (T24) Cells, Michelle S. M. Li

Electronic Thesis and Dissertation Repository

Scanning electrochemical microscopy (SECM) employs a biased ultramicroelectrode (few nm to 25 µm diameter) as a probe that is scanned over a sample to electrochemically characterize its physical properties and chemical reactivity with high temporal and spatial resolutions. In this dissertation, SECM was used to investigate the membrane responses of single live human bladder cancer (T24) cells to obtain insights into their topography, physiology and pathology.

First, the membrane-impermeable ferrocene carboxylate was used as the SECM redox mediator to investigate the geometry and topography of these cells along with 3D finite elemental analysis (FEA) simulations. The use of 3D simulation …

Construction And Analysis Of Accurate Exchange-Correlation Potentials, Sviataslau V. Kohut

Electronic Thesis and Dissertation Repository

Practical Kohn–Sham density-functional calculations require approximations to the exchange-correlation energy functional, E_XC[ρ], or the exchange-correlation potential, v_XC(r), defined as the functional derivative of E_XC[ρ] with respect to the electron density, ρ. This thesis focuses on the following problems: (i) development of approximate exchange-correlation potentials by modelling the exchange-correlation charge distribution; (ii) accurate approximation of functional derivatives of orbital-dependent functionals; (iii) generation of exchange-correlation potentials from many-electron wavefunctions; (iv) analysis of accurate exchange-correlation potentials in atoms and molecules.

The advantage of modelling the exchange-correlation potential through the exchange-correlation …

Poly(Ethyl Glyoxylate) Solid-Core Particles For Drug Delivery, Michael Thomas Gambles

Electronic Thesis and Dissertation Repository

The ability to trigger the degradation of polymeric nanoparticles (NPs) by a specific stimulus can provide a method of improved drug targeting and selective release capabilities in vivo. The challenge for most polymeric drug delivery systems remains the necessity for many stimuli events to trigger the release of cargo. Polymeric nanotechnology containing “self-immolative polymers” looks to alleviate the reliance on high concentrations of stimuli by undergoing complete end-to-end depolymerization via a single stimulus-mediated reaction of an end-cap. Herein, NPs were developed using poly(ethyl glyoxylate) (PEtG) blended with poly(d,l-lactic acid) (PLA) to encapsulate a hydrophobic cargo to be released upon …

Design And Synthesis Of Hyaluronan:Rhamm Interaction Inhibitors, Emily Rodrigues

Electronic Thesis and Dissertation Repository

A major component of the extracellular matrix is hyaluronan, a regulator of cell migration/survival and differentiation during response-to-injury processes. The receptor for hyaluronan-mediated motility (RHAMM) binds to HA and has limited constitutive expression but is upregulated during tissue injury. Blocking HA fragment:RHAMM interactions has therapeutic potential for treating cancer but truncation of RHAMM into peptides mimicking only the HA binding domains is predicted to lose their natural α-helical structure. The goal of this project is to explore the effects cyclizing each binding domain has on helicity and its biological effect. Eighteen peptides were synthesized and cyclized using lactam bridges. The …

Crystal Engineering Of Active Pharmaceutical Ingredients With Low Aqueous Solubility And Bioavailability, Jenna M. Skieneh

Electronic Thesis and Dissertation Repository

Approximately 75% of new molecular entities approved by the Food and Drug Administration (FDA) for use in the pharmaceutical industry are found to have poor aqueous solubility. This undesirable attribute leads to consequences such as higher doses required to reach therapeutic levels, greater vulnerability to food effects, lesser fraction absorbed in the small intestine and damage to the environment due to increased quantity of excretion. The addition of an excipient (i.e. a FDA approved inactive ingredient) to the molecular structure of an active pharmaceutical ingredient (API) through intermolecular bonding is of growing interest because the properties of the API can …

Structural Modification, Polymerization And Applications Of Boron Difluoride Formazanates, Stephanie M. Barbon

Electronic Thesis and Dissertation Repository

This thesis describes the synthesis and characterization of a new family of fluorescent and redox-active BF₂ complexes of formazanate [R¹-N-N=C(R³)-N=N-R⁵]⁻ ligands. The complexes were easily synthesized in two high-yielding steps, from inexpensive starting materials and readily purified by conventional methods. The properties of the resulting complexes can be tuned through structural variation – for example, appending electron donating or withdrawing substituents, or extending π conjugation. These methods of structural variation can bathochromically or hypsochromically shift the maximum absorption and emission wavelengths, vary the quantum yields, and allow for tuning of the reduction …

Molecular And Polymeric Materials Based On Asymmetrically Substituted Bf2 3-Cyanoformazanates, Samantha Novoa

Electronic Thesis and Dissertation Repository

This thesis outlines the synthesis and characterization of asymmetric and symmetric 3-cyanoformazanate BF₂ complexes and their incorporation into polymers. CuAAC chemistry was used to synthesize two additional asymmetric BF₂ complexes and a side product that was identified as a symmetric dimer. Spectroscopic and electrochemical properties of these compounds are described.

Incorporation of an asymmetric 3-cyanoformazante BF₂ complex into polymers was done by ROMP. This reaction was used to make homo, block, and random copolymers, where the comonomer was an organic norbornene derivative. Spectroscopic studies of these polymers revealed that, as the mole fraction of BF₂ (ƒ …

Evolution Of Cu2o Morphology During Copper Corrosion In The Presence Of Gamma-Radiation, Arielle M. Jean

Electronic Thesis and Dissertation Repository

In this work, experiments were carried out in order to develop a mechanistic understanding of the corrosion of copper metal in limited water volumes under gamma-radiation. When exposed to gamma-radiation, water decomposes into chemically reactive oxidizing and reducing species. Under a continuous radiation flux, the concentrations of the radiolytically produced oxidants eventually reach a pseudo-steady state that can influence the corrosion kinetics of metallic surfaces.

The evolution of the surface morphology during water droplet corrosion of copper in the presence of gamma-radiation was investigated as a function of irradiation time and pH. The oxide growth kinetics were studied by measuring …

A Chlorine-Free Protocol For Processing Silicon, Germanium, And Tin, Michael J. Krause

Electronic Thesis and Dissertation Repository

Replacing molecular chlorine and hydrochloric acid with less energy- and risk-intensive reagents would dramatically improve the environmental impact of metal manufacturing at a time when demand for metals is rapidly increasing. Germanium and tin are classified as “critical” elements based on growing demand for these elements in technological applications, lack of suitable substitutes, and, for germanium, high dispersion in the environment making extraction of the element process-intensive. This thesis describes a recyclable quinone / catechol redox platform that provides an innovative replacement for elemental chlorine and hydrochloric acid in the conversion of germanium metal or tin metal to element tetrachloride …

Doubly Bonded Derivatives Of Si And Ge: Cycloaddition Reactions And Polymer Chemistry, Bahareh Farhadpour

Electronic Thesis and Dissertation Repository

(Di)tetrelenes are a fundamental class of unsaturated Group 14 compounds and play a central role in the synthesis of functional Group 14 compounds. The objective of this research was to investigate the various aspects of group 14 (di)tetrelenes (R₂M=ER₂, M = Si, Ge, and E = C, Si, Ge) reactivity.

The addition of a series of nitrone and nitro compounds to the group 14 (di)tetrelenes 
Mes₂Si=SiMes₂, Mes₂Ge=GeMes₂ and Mes₂Ge=CH(CH₂-t-Bu), was examined. In general, the addition of the 1,3-dipolar nitrogen oxides to the (di)tetrelene …

Metalation And Structural Properties Of Apo-Metallothioneins, Gordon W. Irvine

Electronic Thesis and Dissertation Repository

Metals are required by a quarter of all proteins to achieve their biological function, whether in an active site involved in catalytic chemistry or in a structural capacity. Metals are tightly regulated at the cellular level due to their propensity to cause unwanted side reactions and to be scavenged for use by pathogens. One of the proteins involved in this regulation of metal homeostasis is metallothionein (MT) which is a small, cysteine rich protein primarily involved in the regulation of zinc and copper homeostasis and heavy metal detoxification. MT is unique in its high cysteine content (~30% of the residues), …

Electrochemical And Modelling Studies On Simulated Spent Nuclear Fuel Corrosion Under Permanent Waste Disposal Conditions, Nazhen Liu

Electronic Thesis and Dissertation Repository

The safety assessment models for the deep geological disposal of spent nuclear fuel require a fundamental understanding of the corrosion of spent fuel in a failed waste container. The overall research goal of this project is to investigate the corrosion of simulated spent fuel under permanent disposal conditions, using both model simulations and experimental investigations. A model for fuel corrosion has been expanded to determine the relative importance of radiolytic hydrogen and hydrogen from corrosion of the steel vessel in suppressing fuel corrosion. It was shown that, for CANDU (CANada Deuterium Uranium) fuel with moderate in-reactor burnup, only micromolar concentrations …

Synthesis Of Manganese(Ii) Containing Metal Chalcogen Cluster Complexes From Metal Trimethylsilylthiolate Precursors, Kyle Nw Rozic

Electronic Thesis and Dissertation Repository

The manganese(II)‐palladium(II)‐sulfide complex [MnCl₂(μ₃‐S)₂Pd₂(dppp)₂] 2 has been isolated from the reaction of [(dppp)PdCl₂] with [Li(N,N’‐tmeda)]₂[Mn(SSiMe₃)₄] 1 in a 2:1 ratio under mild conditions. The trimethylsilyl thiolate complex [(dppp)Pd(SSiMe₃)₂] 3 has been synthesized from the reaction of [(dppp)PdCl₂] with Li[SSiMe₃] as well as the reaction of [(dppp)Pd(OAc)₂] with Li[SSiMe₃] under mild conditions. The newly synthesized complex [(dppp)Pd(SSiMe₃)₂] 3 was used in reaction with the manganese(II) salt [(CH …

Integration Of Orbital-Dependent Exchange-Correlation Potentials, Hanqing Zhao

Electronic Thesis and Dissertation Repository

In density-functional theory, one can approximate either the exchange-correlation energy functional or the corresponding Kohn--Sham effective potential, which is then converted into an energy functional by functional integration. A directly approximated potential may depend on the electron density explicitly or implicitly through Kohn--Sham orbitals. A potential that depends on the electron density explicitly can be converted into an energy functional by evaluating the Leeuwen--Baerends line integral along some path of electron densities. We extend this technique to orbital-dependent potentials by integrating them along the path of scaled orbitals. Using this method, we assign energy expressions to the Slater, Becke--Johnson and …