Inorganic Chemistry Commons^™

Electrolyte Effects On The Kinetics Of Comproportionation Electron-Transfer Reactions And On Intervalence Charge-Transfer Band Energies Of Binuclear Ruthenium Ammine Complexes, Zhiji Han

Master's Theses

Chapter 1 describes an overview of electron-transfer reactions. The kinetic equations for ET reactions have also been described in detail.

Chapter 2 describes a series of novel kinetic accelerations which deviate strongly from the predictions of the classical Debye-Huckle theory with a range of different added “inert” electrolytes. The greater catalytic effects seen with the heavier halides and other catalytic electrolytes (especially certain dicarboxylates) indicate an important role for hole-transfer superexchange in the ET transition state. The hypothesis of a catalytic ternary association complex, [RuII--X--RuIII] has also been explored by kinetic modeling of the reaction. An increasing ratio of anion-catalyzed …

New Dion-Jacobson And Ruddlesden- Popper Layered Perovskites Prepared By Topochemical Methods, Dariush Montasserasadi

LSU New Orleans Theses and Dissertations

Layered perovskites can be classified in three major groups: Dion-Jacobson AA′_n-1B_nO_3n+1, Ruddlesden-Popper A₂A′_n-1B_nO_3n+1,and Aurivillius phase (Bi₂O₂)A′_n-1B_nO_3n+1. (A: Alkali metal, Alkali-earth metal; A′: Lanthanides and Bi; B: Ti, Nb, Ta; n: thickness of slabs). For more than two decades researchers have shown much interest in this series because of their magnetic and electrical properties. Tuning synthesis parameters such as temperature, time, and host structure can be used to direct such properties. Low temperature synthetic methods (topochemical methods) allow …

Study Of Mechanical Properties Of Pva Fiber-Reinforced Concrete With Raman Spectroscopic Analysis, Ramyasree Annam

Masters Theses & Specialist Projects

The brittleness of concrete has always been a safety and economic issue of great concern. The low tensile strength of concrete is the cause of its intrinsic brittle nature. This is critical considering the amount of concrete used for the construction of highways, buildings, and other facilities. The mechanical properties of concrete must be improved to provide upgraded construction. Crack resistant and durable concrete has always been a major goal for engineers. Many approaches have been tried to make concrete a better construction material. Fiber reinforcement is an approach which has been shown to improve the quality and durability of …

A Study Of The Kinetics Of A Reaction Between Vo(Hedta)-1 And Hydrogen Peroxide, Elaina B. Campbell

Undergraduate Honors Theses

Vanadium is commonly used as an agent to make tools rust-resistant. As a transition metal, it can be used as a catalyst due to its ability to change oxidation states. VO(HEDTA)^-1, a complex of the vanadyl ion, VO²⁺ and HEDTA (N-(2-Hydroxyethyl)ethylenediamine-N,N’,N’-triacetic acid) was readily formed. This complex containing vanadium in the +4 oxidation state was reacted with hydrogen peroxide to form a vanadate complex. This vanadate complex was formed as a first step in simulating the vanadate(V)-dependent haloperoxidases in marine algae, a yet uncharacterized reaction. Electron absorption spectroscopy (UV-Vis) was used to observe the oxidation of V(IV) …

Electrostatic Assembly Of Gold Nanoparticles Mediated By Polyoxomolybdates, Shannon M. Walter

Renée Crown University Honors Thesis Projects - All

The electrostatic assembly of cationic gold nanoparticles (AuNPs) with core diameters of approximately 1.5 nm and 4.5 nm and the anionic sphere and wheel polyoxomolybdates (Mo-132a), (Mo‑132b), and (Mo‑154) was investigated. The AuNPs were capped with a trimethylammonium terminated ligand. Zeta potential and UV-Vis studies supported the successful assembly of the oppositely charged species. The ratio at which the precipitation of aggregates from solution occurred was consistent with the point of electroneutrality observed in the zeta potential results. The UV-Vis studies showed the loss of the surface plasmon resonance (SPR) band as this point of electroneutrality was approached.

In a …

Syntheses, Structures And Properties Of Metal-Organic Frameworks, Xin Liu

Masters Theses & Specialist Projects

Mercury is one of the most serious heavy metal pollution sources that threaten people’s health. For decades, people have developed many technologies and materials to capture mercury from flue gas of coal-fired plant. Currently, the most effective material for mercury absorption is powdered activated carbon, which shows increased efficiency when modified with halogen functional groups such as bromine. Metal-organic frameworks (MOFs) have potential applications in mercury capture due to their fantastic properties such as high porosity and high thermal stability. More important, their pore sizes and topology structures can be controlled through choosing different organic ligands in the syntheses. However, …

Green Chemistry As A Tool For Understanding The Toxic Substances Control Act: A Lecture Module For Undergraduate Students, Molly R. Blessing

Honors Scholar Theses

The Toxic Substances Control Act (TSCA) is the central form of chemical regulation existent in the United States today, yet scientists are often unaware or uncertain of its provisions. Violations of TSCA by unknowing chemists set industry and government unnecessarily at odds. A lecture on TSCA was developed for undergraduate students that uses the concept of green chemistry to promote interest and incentivize learning. Green chemistry methods are cleaner and less wasteful than traditional chemical ones, and many companies using them are at the forefront of technological innovation. The lecture explains both green chemistry and TSCA, includes company case studies, …

Synthesis And Characterization Of Rhodium Acetate With Functionalized Benzonitriles, Jared M. Lowe

Undergraduate Honors Theses

Dirhodium complexes are effective catalysts in carbene transformations. These reactions involve chemistry between the catalyst and a carbene generated in situ. In order to better understand the rhodium-carbon bond, studies of rhodium acetate, Rh₂(OAc)₄, and a variety of functionalized benzonitriles were proposed. Diadducts of rhodium acetate with 4-nitrobenzonitrile, 4-aminobenzonitrile, 4-(dimethylamino)benzonitrile, and 3,5-dinitrobenzonitrile were successfully prepared and characterized by X-ray crystallography. IR and NMR spectroscopy were also employed for characterization purposes.

Synthesis, Characterization, And Catalytic Applications Of Porous Transition-Metal Oxide Systems For The Conversion Of Biomass, Anton Gudz

Honors Scholar Theses

The development of innovative strategies and environmentally-friendly resources for the sustainable production of fuels and chemicals from renewable materials has recently received much interest in the scientific world. Among such resources, biomass has enormous potential as a raw material for generation of green fine chemicals to replace the petroleum feedstocks currently in place. Biomass derived carbohydrates can be converted into such valuable platform chemicals as levulinates, 5-hydroxymethyl furfural (HMF), and lactates. In order to catalyze the biomass conversion process, porous transition-metal oxide catalytic systems have been developed in this study. High catalytic activities and potential for reusability of such systems …

Synthesis And Characterization Of Five New Tetrakis(N-Phenylacetamidato) Dirhodium(Ii) Amine Complexes And One Molybdenum Cofactor Described Crystallographically, Cragin K. Harris

Electronic Theses and Dissertations

Six new crystal structures were determined using a Rigaku Mercurcy 375/MCCD(XtaLab mini) diffractometer. The structure of a molybdenum cofactor was solved resulting in an R1 (R1 = Σ ||Fo| - |Fc|| / Σ |Fo|) of 3.61% despite the presence of a disordered DMSO molecule. New Tetrakis(N-phenylacetamidato) Dirhodium(II) complexes were synthesized and characterized. Two 2,2-cis-[Rh2(NPhCOCH3)4]•(C3H4N2)x where x= 1 or 2 were successfully crystallized and solved with R1 values below 5%. Additional studies were conducted via NMR to observe formation of both products. Three potential catalysts were synthesized starting with 3,1-[Rh₂(NPhCOCH₃)₄]. The resulting compounds were a …

Imidazolium Salts As Reaction Media For The Preparation Of Metal Halide Cluster Networks, Stephanie K. Gnewuch

Undergraduate Honors Thesis Projects

This study investigated two different schemes of imidazolium and carboxylate salts to assess their use in preparing metal halide cluster networks. The first scheme used salts of 1-ethyl-3-methylimidazolium [EMIM]⁺ and 1-butyl-3-methylimidazolium [BMIM]⁺ as the cations and benzene-1,3,5-tricarboxylate [TMA]-, benzene 1,3-dicarboxylate [IPA]-, and benzene-1,4-dicarboxylate [TPA]- as the anions. The anions are commonly used in porous inorganic materials synthesis, as the size of the cation has been shown to often impact the final structure of the materials. The anions are common bridging ligands used to create network solids. The second scheme used 1,3-dimethylimidazolium triflate [DMIM]⁺ [OTf]^- and sodium …

Synthetic And Mechanistic Studies Of Ruthenium Catalyzed C-C, C-N And C-O Bond Activation Reactions, Nishantha Kumara Kalutharage

Dissertations (1934 -)

Transition metal catalyzed selective C-C, C-N and C-O bond activation reactions are fundamentally important in organometallic chemistry and organic synthesis. Catalytic C-C, C-N and C-O activation are highly valuable for reforming processes of crude oils. Significant research has been devoted to transition metal mediated C-C, C-N and C-O bond cleavage reactions to form new compounds as these processes are expected to provide novel ways to transformation of inexpensive hydrocarbons into more commercially valuable products such as pharmaceuticals, agrochemicals and polymers. A few examples of transition metal catalyzed cross coupling reactions involving C-N bond cleavage have been reported. A well-defined Ru …

Studies Of Arctic Halogen Chemistry From The Snowpack To The Gas Phase, Kyle D Custard

Open Access Dissertations

The temporary depletion of both tropospheric ozone and gaseous mercury during the Arctic springtime has been a focus of active research over the past several decades. Both of these phenomena have been linked to chemical reactions with halogen radicals. In particular, bromine atoms have been shown to act as the primary driver for these chemical depletions, although both chlorine and iodine atoms also contribute. Molecular bromine, along with its oxidation products, have been well studied in the Arctic, yet chlorine has not. Chlorine is known to impact the local oxidation capacity via its high reactivity with volatile organic compounds. Despite …

L-Lactide And Ε-Caprolactone Ring Opening Polymerization By Binary Catalysts Systems That Include Bis-Ligated Magnesium Complexes, Reile M. Slattery, Arnold L. Rheingold, Joseph M. Fritsch

Seaver College Research And Scholarly Achievement Symposium

A series of bis-ligated magnesium complexes supported by tridentate ketoiminates containing electron-donating and electron-withdrawing groups were prepared. The complexes were characterized with ¹H, ¹³C, and ¹⁹F NMR, absorbance spectroscopy, and x-ray crystallography. The complexes were assessed for their ring opening polymerization activity with L-lactide (L-lac) and ϵ-caprolactone (eCL) in binary catalyst systems with 4-fluorophenol at 100 °C. The magnesium complexes supported by ketoiminates bearing electron-donating groups yielded greater percentage conversions from monomers to polymers than those containing electron-withdrawing groups for both L-lac and eCL. The magnesium complexes were more efficient at polymerizing L-lac than eCL, and …

Structure-Function Relationships Affecting The Sensing Mechanism Of Monolayer-Protected Cluster Doped Xerogel Amperometric Glucose Biosensors, Luke T. Dipasquale, Nicholas G. Poulos, Jackson R. Hall, Aastha Minocha, Tram Anh Bui, Michael C. Leopold

Chemistry Faculty Publications

A systematic study of the structure–function relationships critical to understanding the sensing mechanism of 1st generation amperometric glucose biosensors with an embedded nanoparticle (NP) network is presented. Xerogel-based films featuring embedded glucose oxidase enzyme and doped with alkanethiolate-protected gold NPs, known as monolayer protected clusters (MPCs), exhibit significantly enhanced performance compared to analogous systems without NPs including higher sensitivity, faster response time, and extended linear/dynamic ranges. The proposed mechanism involves diffusion of the glucose to glucose oxidase within the xerogel, enzymatic reaction production of H2O2 with subsequent diffusion to the embedded network of MPCs where it is oxidized, an event …

Quantitative Analysis Of Heavy Metals In Children’S Toys And Jewelry: A Multi-Instrument, Multi-Technique Exercise In Analytical Chemistry And Public Health, Lauren E. Finch, Margot M. Hillyer, Michael C. Leopold

Chemistry Faculty Publications

For most chemistry curricula, laboratory-based activities in quantitative and instrumental analysis continue to be an important aspect of student development/training, one that can be more effective if conceptual understanding is delivered through an inquiry-based process relating the material to relevant issues of public interest and student career trajectories. Laboratory experiences that actively engage students in this manner can be difficult to identify and execute. A special topics, project-based laboratory module is presented here that utilizes multiple techniques and instruments to investigate toxic metal content (lead, cadmium, and arsenic) in children’s toys and toy jewelry. The module effectively illustrates a considerable …

Functional Layer-By-Layer Design Of Xerogel-Based 1st Generation Amperometric Glucose Biosensors, Nicholas G. Poulos, Jackson R. Hall, Michael C. Leopold

Chemistry Faculty Publications

Xerogel-based first-generation amperometric glucose biosensors, constructed through specific layer-by-layer assembly of films featuring glucose oxidase doped xerogel, a diffusion-limiting xerogel layer, and capped with both electropolymerized polyphenol and blended polyurethane semipermeable membranes, are presented. The specific combination of xerogels formed from specific silane precursors, including propyl-trimethoxysilane, isobutyl-trimethoxysilane, octyl-trimethoxysilane, and hydroxymethyl-triethoxysilane, exhibit impressive dynamic and linear ranges of detection (e.g., ≥24–28 mM glucose) and low response times, as well as significant discrimination against common interferent species such as acetaminophen, ascorbic acid, sodium nitrite, oxalic acid, and uric acid as determined by selectivity coefficients. Additionally, systematic electrochemical and contact angle studies of …

Preparation, Crystal Structure, Thermal Analysis, Scanning Electron Microscopy And Optical Band-Gaps Of Cu2gete4 And Cu2snte4 Alloys, Pedro Grima Gallardo, Ricardo Pena, Luis Nieves, Gustavo Marcano, Miguel Quintero, Ekadink Moreno, Jian-Han Zhang, Jacilynn A. Brant, Jennifer A. Aitken

Chemistry and Physics Faculty Articles

Polycrystalline samples (weight ~ 1g) of Cu ₂ GeTe ₄ and Cu ₂ SnTe ₄ alloys were prepared by the usual melt and anneal method and the products characterized by X-Ray Diffraction (XRD), Differential Thermal Analysis (DTA), Scanning Electron Microscopy (SEM) and Optical Diffuse Reflectance UV / VIS / NIR Spectroscopytechniques. It was found that: a) Cu ₂ GeTe ₄ and Cu ₂ SnTe ₄ crystallize in an orthorhombic structure (sg Imm2; N ^o44) with lattice parameters a = 5.9281 (4) Å, b = 4.2211 (6) Å, c = 12.645 (5) Å and a = 6.0375 (6) Å, b …

Investigation Into The Biological Importance And Function Of Proinsulin C-Peptide, Christina L. Newsome

Theses, Dissertations and Capstones

The C-peptide of insulin was thought to be biologically inactive, but recent studies have shown that the C-peptide causes multiple molecular and physiological effects. Evidence has shown that C-peptide binds to a cell surface receptor, probably a G-protein coupled receptor, and that the COOH-terminal pentapeptide is essential for binding and constitutes an active site. For a further understanding of the detailed nature of the physiological effects of C-peptide, the receptor structure needs to be determined. We designed an affinity column using C-peptide to try and gain a better understanding of the biological effects by examining what proteins the affinity column …

On The Nature Of Excited States In Ruthenium Complexes: Towards Renewable Energy, Ryan A. Thomas

Wayne State University Dissertations

The 77 K radiative properties (spectra, quantum yields and lifetimes) of ruthenium-polypyridyl complexes are investigated to better understand the effects of electronic mixing on metal-to-ligand-charge-transfer (3MLCT) excited state properties and how metal-centered (3MC) excited states affect the properties of potential ruthenium photosensitizers.The radiative rate of relaxation (kRAD) determines the maximum possible excited state lifetime when all other relaxation pathways are blocked (kn = 0 for all n  RAD). Thus, the excited state will relax only by means of an emission characteristic of the polypyridyl chromophore. kRAD is expected to increase as the excited state energy increases while the value …