Physical Sciences and Mathematics Commons^™

Transition Metal Complexes With Reactive Trimethylsilylchalcogenolate Ligands: Precursors For The Preparation Of Ternary Nanoclusters, Chhatra Bahadur Khadka

Electronic Thesis and Dissertation Repository

The Co²⁺ and Mn²⁺ complexes (N,N´-tmeda)Co(ESiMe₃)₂ (E = S, 1a; E = Se, 1b), (3,5-Me₂C₅H₃N)₂Co(ESiMe₃)₂ (E = S, 2a; E = Se, 2b), [Li(N,N´-tmeda)]₂[(N,N´-tmeda)Mn₅(μ-ESiMe₃)₂(ESiMe₃)₄(μ₄-E)(μ₃-E)₂] (E = S, 3a; E = Se, 3b), [Li(N,N´-tmeda)]₂[Mn(SSiMe₃)₄] (4), [Li(N,N´-tmeda)]4[Mn₄(SeSiMe₃)₄(μ_{3 …}

Investigating Interfacial Reactions Of Silver-Containing Films Using Novel Methods, Sarah Danielle Pretty

Electronic Thesis and Dissertation Repository

This thesis presents work on the mechanism and kinetics of the surface film reactions involving the conversion of aqueous species on solid surfaces, and specifically, the reactions of iodide and bromide on silver oxide on silver substrate. These reactions provide a method of immobilizing unwanted halides and are particularly suited to control of hazardous radioactive iodine. Potential applications of this research include nuclear reactor safety and post-accident radioiodine management, and the safe production and use of the medical isotope ¹³¹I.

The aqueous-solid conversion of reaction Ag₂O with X^-(aq) to form AgX on a Ag substrate …

Reactivity Of Dimethylplatinum (Ii) Complexes, Muhieddine A. Safa

Electronic Thesis and Dissertation Repository

This thesis describes a study of dimethylplatinum(II) and dimethylplatinum(IV) complexes containing bidentate nitrogen donor ligands. This work deals with oxidative addition, and reductive elimination chemistry, and it focuses on synthesis, characterization, and reaction mechanisms in studies of these complexes.

The compound [PtMe₂(bpe)], bpe = 1,2-bis(2-pyridyl)ethane, is easily oxidized to give octahedral organoplatinum(IV) complexes and the subsequent chemistry is profoundly influenced by the accompanying strain induced in the 7-membered Pt(bpe) chelate ring. On reaction of [PtMe₂(bpe)] with HCl, the initial product [PtHClMe₂(bpe)] undergoes reductive elimination of methane to form [PtClMe(bpe)]. In contrast, methyl …

Structure And Dynamics Of The Membrane Protein Bacteriorhodopsin Studied By Mass Spectrometry, Yan Pan

Electronic Thesis and Dissertation Repository

Membrane proteins continue to represent a major challenge for most analytical techniques. Using bacteriorhodopsin (BR) as model system, this work aims to develop mass spectrometry (MS)-based approaches for exploring the structure, dynamics and folding of membrane proteins.

As the first step, BR in its native lipid environment was exposed to hydroxyl radicals, which were produced by laser photolysis of hydrogen peroxide. It was found that the resulting methionine (Met) labeling pattern was consistent with the known BR structure. This finding demonstrates that laser-induced oxidative Met labeling can provide structural information on membrane proteins. In subsequent experiments, the effects of different …

Development Of Single And Multimodality Imaging Probes For Pet, Spect And Fluorescence Imaging, Babak Behnam Azad

Electronic Thesis and Dissertation Repository

This dissertation is in an integrated format discussing three major projects centered around probe development. In the first project, novel metal-chelated and fluorinated GLP-1 derivatives were prepared all containing D-Ala-8, a modification known to improve resistance towards degradation by dipeptidyl-peptidase IV. The effect of increased distance between DOTA and the peptide chain was investigated using a spacer, in order to reduce steric effects imposed by DOTA. Placement of linker and DOTA moieties were varied within the GLP-1 sequence to test for optimal metal-complex location. Binding affinity of peptide derivatives was determined in vitro with CHO/GLP-1R cell line and shown to …

Electronic And Magnetic Excitations In Graphene And Magnetic Nano-Ribbons, Maher Zakaria Ahmed Selim

Electronic Thesis and Dissertation Repository

The discovery of graphene - a 2D material with superior physical properties - in 2004 was important for the intensive global research to find alternatives to three-dimensional (3D) semiconductor materials in industry. At the same time there have been exciting advances for 2D magnetic materials on the nanometer scale. The superior properties of graphene are mainly attributed to its crystal structure and its relatively short-range interactions. These properties show that natural and artificial 2D materials are promising for new applications.

In this thesis we have carried out a comprehensive investigation of the effects of the 2D lattice structures, the roles …

Uncovering New Bonding Motifs: The Synthesis Of Chalcogen And Phosphorus Complexes Supported By Nitrogen Based Ligands, Caleb D. Martin

Electronic Thesis and Dissertation Repository

The chemistry of the main group elements with nitrogen based ligands has been an area that has received little attention in comparison to transition metals. The preliminary investigations have focused on groups 13 and 14 revealing new bonding motifs and interesting reactivity. This has motivated us to synthesize group 15 and 16 derivatives in new bonding arrangements capable of activating small molecules.

In pursuit of isolating such species, the reactivity of sulfur dichloride and “S(OTf)2” with a series of diazabutadiene (DAB) ligands was explored. The substitution on the ligand was extremely influential on the outcome of the reaction. Alkyl groups …

Molecular Dynamics Simulations Of Charged Nanodroplets, Elias Ahadi

Electronic Thesis and Dissertation Repository

Charged nanodroplets represent a fascinating research area due to their unique dynamics and physical properties. These nanodroplets play a key role in electrospray mass spectrometry (ESI-MS), which is a method for analyzing organic/inorganic molecules as well as proteins and other biomolecular species. The mechanism whereby these analytes are transferred into the gas phase as intact ions remains incompletely understood. Two competing models have been proposed to explain the process, the charged residue model (CRM) and the ion evaporation model (IEM). Under the CRM, evaporation of the droplet proceeds until dryness, at which point the analyte ion is left behind. Under …

Rational Design And Advanced Fabrication Of Metallic Nanostructures For Surface-Enhanced Raman Spectroscopy, Betty Cristina Galarreta

Electronic Thesis and Dissertation Repository

One of the main challenges in analytical science and technology is to develop devices that provide unambiguously the chemical nature of the material of interest with the minimum intrusiveness, the smallest amount of analyte, and the shortest acquisition time. Among the promising methods for such purpose, optical spectroscopy such as surface-enhanced Raman scattering is considered a suitable option. This spectroscopic technique takes advantage of the interaction between an optical field and metallic nanostructures to magnify the electromagnetic field in the vicinity of the nanostructure, resulting in an amplified signal of the vibrational fingerprints of the adsorbed molecules onto the metallic …

Strategies For The Thermal And Photochemical Modification Of Gold Nanoparticles (Aunps) And The Fabrication Of Aunp Hybrid Materials, Hossein Ismaili

Electronic Thesis and Dissertation Repository

Among the existing approaches for the functionalization of the gold nanoparticle (AuNP), a direct interfacial organic reaction of terminal functional groups exposed on the surface of template nanoparticles with various reactants has been shown as a promising strategy to incorporate desired functionality onto the AuNP monolayer. In our own attempts to extend the types of reactions that can be utilized for efficient interfacial modifications of AuNPs, we examined uncatalyzed Huisgen 1,3-dipolar click-type cycloaddition of azide-modified AuNPs to terminal alkynes. These particular reactions were found to be generally too slow to be useful at ambient temperatures but it was shown that …

X-Ray Photoelectron Spectroscopy Studies On The Oxidation Processes Of Nickel, Chromium And Their Alloys, Bradley P. Payne

Electronic Thesis and Dissertation Repository

The reaction of polycrystalline Ni metal surfaces with low pressures (~ 130 Pa) of O₂ gas or H₂O vapour produced thin defective nickel oxide films containing both Ni²⁺ and Ni³⁺ species at 25^oC and 300^oC. Exposure of Ni metal samples to H₂O vapour resulted in a much slower reaction rate when compared to similar doses of O₂ gas. This difference was attributed to a slower place exchange with a surface hydroxyl (OH (ads)) intermediate compared to that of an adsorbed oxygen atom (O (ads)). This OH (ads) species …

Double Helical Hydrogen-Bonded Aaa-Ddd Complexes And Supramolecular Polymers, Hong-Bo Wang

Electronic Thesis and Dissertation Repository

The design and characterization of linear oligomers that self-assemble into double helical structures has been a subject of interest to chemists since the elucidation of the double helix structure of DNA in 1953. Transition metal templates have been widely used in the construction of artificial double helical complexes from linear multidentate ligands. The use of other non-covalent interactions as the driving force in the self-assembly of these types of complexes is less common. Aromatic stacking interactions, anion templates, and salt-bridges have all been applied in this context. The great majority of these investigations have been concerned with the dimerization of …

Exploring The Chemistry Of Cyclopentadienyl-Cobalt-Cyclobutadiene (Cpcocb) Complexes And Synthesis Of Side-Chain Cpcocb Polymers, Preeti Chadha

Electronic Thesis and Dissertation Repository

Synthetic metallopolymers have acquired ample attention recently due to their potential applications as precursors to functional soft materials. Organometallic polymers combine the best of both organic and inorganic polymers. Polyferrocenes comprise the major portion of organometallic polymers. Therefore, quest for new monomeric precursors to organometallic polymers has expediated. One efficient method for obtaining main-chain metallopolymers is by the ring opening polymerization (ROP) of strained cyclic metallacylophanes(MCPs). Organometallic polymers containing cyclopentadienyl-cobalt-cyclobutadiene (CpCoCb) have been targeted since early 1990’s due to their isoelectronic nature (cf. ferrocene) with three major groups working in this area. The early CpCoCb containing polymers were prepared …

The Effect Of The Environment On The Corrosion Products And Corrosion Rates On Gas Transmission Pipelines, Brent Sherar

Electronic Thesis and Dissertation Repository

This thesis reports a series of investigations examining external corrosion processes along gas transmission pipelines. TransCanada PipeLines Ltd. (TCPL) has developed six proposed corrosion scenarios to describe external pipeline corrosion, based primarily on corrosion products and corrosion rates (CRs) observed at field sites. The six proposed corrosion scenarios can be divided into two groups: abiotic and biotic. The three abiotic corrosion scenarios are (1) anaerobic corrosion, (2) aerobic corrosion, and (3) anaerobic corrosion turning aerobic; while (4) anaerobic corrosion with microbial effects, (5) aerobic corrosion turning anaerobic with microbial effects, and (6) anaerobic corrosion with microbial effects turning aerobic comprise …

Design And Syntheses Of Fluorescent Cytosine Analogues, David W. Dodd

Electronic Thesis and Dissertation Repository

The avid hybridization of peptide nucleic acid (PNA) to DNA and RNA along with the molecule’s biological stability has led it to be used in both antisense and antigene capacities. PNA acts against translation via a steric blockade mechanism. It is therefore reasonable to assume that increased heteroduplex stability could lead to increased potency. Two ways of doing this were explored. I) N-Terminal attachment of a platinous chloride chelating moiety to PNA complementary to Xenopus noggin was synthesized with the objective of selective, covalent platination of the target transcript in vivo. Phenotypes consistent with knockdown of the selected …

The Formal [4+3] Cycloaddition Between Donor-Acceptor Cyclobutanes And Nitrones., Andrew C Stevens, Cory Palmer, Brian L Pagenkopf

Chemistry Publications

The formal [4+3] cycloaddition of 2-alkoxy-1,1-dicarboxylate activated donor-acceptor cyclobutanes with nitrones is disclosed. The reaction forms structurally unique oxazepines in moderate to high yield with a wide scope of nitrones. In most cases either a diastereomeric mixture or a single diastereomer may be formed, depending on the reaction conditions.

New Synthetic Methodologies Directed Toward Pharmacologically Active Compounds As Well As Silole Based Chromophores For Analytical And Optoelectronic Applications, Mahmoud M. Abd Rabo Moustafa

Electronic Thesis and Dissertation Repository

The development of new and efficient synthetic methodologies to prepare heterocyclic compounds has received great attention over the years due to their importance in the pharmaceuticals and fine chemicals industries. Described herein are several novel syntheses of a variety of heterocycles including siloles, azaindoles, piperideines, piperidines and tetrahydropyrans.

A one-pot, two-step methodology involving Tamao’s reductive cyclization followed by Negishi cross coupling was utilized to synthesize several new series of silole-based chromophores. The property studies revealed new electropolymerized poly(thienyl-silole)s with enhanced photoefficiency for all-polymer solar cells. In addition, a new procedure is developed for the synthesis of the first dissymmetric silole …

The Formal [4+3] Cycloaddition Between Donor-Acceptor Cyclobutanes And Nitrones., Andrew C Stevens, Cory Palmer, Brian L Pagenkopf

Chemistry Publications

The formal [4+3] cycloaddition of 2-alkoxy-1,1-dicarboxylate activated donor-acceptor cyclobutanes with nitrones is disclosed. The reaction forms structurally unique oxazepines in moderate to high yield with a wide scope of nitrones. In most cases either a diastereomeric mixture or a single diastereomer may be formed, depending on the reaction conditions.

Gram Scale Synthesis Of The C(18)-C(34) Fragment Of Amphidinolide C., Nicholas A Morra, Brian L Pagenkopf

Chemistry Publications

The synthesis of the C(18)-C(34) fragment of amphidinolide C has been achieved via two routes, culminating in both the shortest (11 steps) and highest yielding (26% overall yield) approaches to this segment. The highly convergent approach will facilitate the synthesis of analogues, including the C(18)-C(29) fragment of amphidinolide F. Synthetic highlights include the selective methylation of a diyne, and the highly efficient use of a second generation cobalt catalyst in the Mukaiyama oxidative cyclization to form the trans-THF ring.

Gram Scale Synthesis Of The C(18)-C(34) Fragment Of Amphidinolide C., Nicholas A Morra, Brian L Pagenkopf

Chemistry Publications

The synthesis of the C(18)-C(34) fragment of amphidinolide C has been achieved via two routes, culminating in both the shortest (11 steps) and highest yielding (26% overall yield) approaches to this segment. The highly convergent approach will facilitate the synthesis of analogues, including the C(18)-C(29) fragment of amphidinolide F. Synthetic highlights include the selective methylation of a diyne, and the highly efficient use of a second generation cobalt catalyst in the Mukaiyama oxidative cyclization to form the trans-THF ring.

Micro- And Nanoparticles In Uv-Cured Thin Films, T. Christopher Corkery, Joseph Chan, Mike J. Idacavage, Elizabeth R. Gillies, Paul J. Ragogna

Chemistry Presentations

No abstract provided.

Bf3·Oet2 Catalyzed Reaction Of Donor-Acceptor Cyclobutanes With Terminal Alkynes: Single Step Access To 2,3-Dihydrooxepines, Ben P Machin, Brian L Pagenkopf

Chemistry Publications

In the presence of BF3˙OEt2 cyclobutane-1,1-diesters undergo a reaction with terminal alkynes to quickly access dihydro­oxepines.