Inorganic Chemistry Commons^™

Part I - A Study Of The Formation Of Carbenes By Elimination Of Α-Bromosilanes And Application Toward The Synthesis Of Transition Metal Complexed Quinone Methide Analogs. Part Ii - Development Of Novel 7-Membered Ring Carbene Ligands For Palladium Catalyzed Cross Coupling Reactions., Christian Michael Loeschel

Graduate Theses and Dissertations

In part I, we wish to report our approaches toward transition metal complexed ortho-quinone methide analogs. ortho-Quinone Methides are a class of highly reactive compounds with a wide range of chemical and biological applications. Previously, a stable iron complexed benzannulated 5-membered ring quinone methide analog was reported by Allison and Neal27. Herein, we report our approaches to improve the reactivity of that system by removing benzannulation as well as changing the metal from iron to manganese and rhenium.

Furthermore, a methodological study on generating carbenes under mild conditions by elimination of α-halosilanes and its application towards metal complexed quinone methide …

Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies, Howard Knachel, Vladimir Benin, Chadwick Barklay, Janine C. Birkbeck, Billy D. Faubion, William E. Moddeman

Chemistry Faculty Publications

The reaction of an isomeric mixture of the methyl perfluoroalkyl ether, C4F9OCH3 (Novec-7100), in the presence of isopropyl alcohol (IPA) and/or water has been studied by measuring the rate of product formation using an ion-selective electrode (ISE) for fluoride ion, Karl Fisher coulometric titrations for water, and 1H and 19F NMR spectroscopy for product identification and rate studies. The results showed the methyl perfluoroalkyl ether to be very stable with products forming at the rate of ∼1 ppm per year at a laboratory temperature of 20 °C. Measurements over the temperature range of 6° to 100 °C were made on …

Novel Single-Site Titanosilicates With Targeted Connectivity And Nuclearity Of Titanium(Iv): Synthesis, Characterization And Catalytic Properties In Alkylphenol Oxidation, Nan Chen

Doctoral Dissertations

Titanosilicates are a family of porous materials that have shown excellent catalytic activity in olefin epoxidation and many other selective oxidation reactions. These materials have been extensively studied in the past few decades. One of the central questions in these investigations has been to define the catalytically active centers. The traditional synthesis of wet impregnation followed by calcination often produces more than one type of catalytic center within the same matrix, i.e. different coordination, connectivity and nuclearity. Each type potentially possesses unique catalytic activity. Co-existence of multiple catalytic centers makes it impossible to establish the relationship between the structure of …

Interaction Of Human Telomeric Dna With N-Methyl Mesoporphyrin Ix, John Michael Nicoludis , '12, Steven Paul Barrett , '13, J.-L. Mergny, Liliya A. Yatsunyk

Chemistry & Biochemistry Faculty Works

The remarkable selectivity of N-methyl mesoporphyrin IX (NMM) for G-quadruplexes (GQs) is long known, however its ability to stabilize and bind GQs has not been investigated in detail. Through the use of circular dichroism, UV-visible spectroscopy and fluorescence resonance energy transfer (FRET) melting assay we have shown that NMM stabilizes human telomeric DNA dAG(3)(TTAG(3))(3) (Tel22) and is selective for its parallel conformation to which it binds in 1:1 stoichiometry with a binding constant of similar to 1.0 x 10(5) M-1. NMM does not interact with an antiparallel conformation of Tel22 in sodium buffer and is the second example in the …

Hierarchy Of Supramolecular Synthons In The Of Design Multi-Component Crystals, Padmini Kavuru

USF Tampa Graduate Theses and Dissertations

Most of the biological systems in nature are sustained by molecular self-assemblies which are the finest examples of supramolecular architectures. Non-covalent interactions are key concepts which govern these molecular assemblies. Inspired by these examples crystal engineering emerged as an important tool in supramolecular chemistry which aids in the invention of new molecular structures with desired properties. Understanding of how the molecules interact at the molecular levels enables one to rationally design novel solid forms with modulated physicochemical properties. This feature of crystal engineering has heightened its position in materials chemistry and is currently one of the most well studied fields …

The Synthesis And Reactivity Of New Pnictogen(Iii) Cations, Allison L. Brazeau

Electronic Thesis and Dissertation Repository

Chelating nitrogen based ligands are well known for their use with transition metals while their chemistry with p-block elements has been relatively underdeveloped. This thesis examines the structure, bonding and reactivity of group 15 elements supported by a pyridyl tethered 1,2-bis(imino)acenaphthene (“clamshell”) and various homo- and heteroleptic guanidinate frameworks.

The unique “clamshell” ligand contains a pendant Lewis base and has been used to support N-heterocyclic phosphenium and arsenium cations. Reactivity studies with the phosphorus analogue demonstrate the ability of the ligand to act as a Lewis base, while the phosphorus centre provides a Lewis acidic site, showing the amphoteric …

Investigating The Electron Transport And Light Scattering Enhancement In Radial Core-Shell Metal-Metal Oxide Novel 3d Nanoarchitectures For Dye Sensitized Solar Cells, Gayatri Sahu

University of New Orleans Theses and Dissertations

Dye-sensitized solar cells (DSSCs) have attained considerable attention during the last decade because of the potential of becoming a low cost alternative to silicon based solar cells. Electron transport is one of the prominent processes in the cell and it is further a complex process because the transport medium is a mesoporous film. The gaps in the pores are completely filled by an electrolyte with high ionic strength, resulting in electron-ion interactions. Therefore, the electron transport in these so called state-of-the-art systems has a practical limit because of the low electron diffusion coefficient (D_n) in this mesoporous film …

The Synthesis And Characterization Of Novel Titanosilicates For Next Generation Hydrogen Storage, James R. Humble

Chancellor’s Honors Program Projects

No abstract provided.

The Itinerant Position Of Yttrium As Evidenced By Carboxylic Acid Extractions, Dustin C Collier

Doctoral Dissertations

The rare-earth elements Y and La-Lu share many similar physical and chemical properties. These similarities are reflected by the difficulty in the complete separation of the rare earths, often requiring hundreds to thousands of stages for the production of pure rare earths. Yttrium, traditionally known to be separated with Ho, has also been observed to be separated with other elements within the lanthanide series, and even outside the bounds of the lanthanide series itself. Previous publications by several authors have indicated that steric factors could influence the position of Y in solvent extractions of the rare earths using carboxylic acid …

Synthesis, Structure, And Characterization Of Hybrid Solids Containing Polyoxometalates And Ruthenium Polypyridyl Complexes, Yanfen Ll

Masters Theses & Specialist Projects

Polyoxometalates (POMs), which are inorganic metal oxide cluster anions with discrete structures, have been extensively studied in recent years due to their large variety of applications such as medicine, biology, catalysis, material sciences and chemical analysis. Ruthenium polypyridyl complexes have been extensively studied for their applications as photosensitizers in solar energy conversion and photoelectronic materials. Recently, ruthenium heterocyclic ligand complex-based building blocks have been used for the synthesis of hybrid organic-inorganic solids through the self-assembly. We are interested in the synthesis of ruthenium polypyridyl complexes and polyoxometalate anions through different ways such as coordination bonds, hydrogen bonds and ionic bonds …

Synthesis And Characterization Of Mesoporous Silica Membranes Modified By Atomic And Molecular Layer Deposition, David Emmett Cassidy

Electronic Theses and Dissertations

Inorganic membranes offer a means for chemical separations in a variety of applications including chemical processing, drug delivery systems, battery separators and fuel cells. There is currently a “pore size gap” in silica membranes between 1-2 nanometers. Synthesizing membranes with a fine control of the pore size and distribution within that gap is a significant challenge. This thesis reports findings on using atomic and molecular layer deposition as new synthesis approaches to controlling pore size and chemical functionality of silica membranes. Mesoporous silica membranes, prepared using surfactant-templates with pore diameters ~4nm, were modified using atomic layer deposition and molecular layer …

Structural Motifs Of Novel Metallothionein Proteins, Duncan E K Sutherland

Electronic Thesis and Dissertation Repository

Metallothioneins (MT) are a family of small cysteine rich proteins, which have been implicated in toxic metal detoxification, protection against oxidative stress, and as a metallochaperone. The most well studied member of the family is the mammalian MT, which consists of two domains: a β-domain with 9 cysteine residues, which sequesters 3 Cd²⁺/Zn²⁺, and an α-domain with 11 cysteine residues, which sequesters 4 Cd²⁺/Zn²⁺. The exact functions of MT are unknown but must relate to its metalation status. Several areas that could lead to the assignment of function include 1) the determination …

Solid-State Nuclear Magnetic Resonance Spectroscopy Of Unreceptive Quadrupolar Nuclei In Inorganic Materials, Andre Sutrisno

Electronic Thesis and Dissertation Repository

Preparation and characterization of inorganic materials is a crucial practice because understanding the relationship between structure and property is important for improving current performance and developing novel materials. Many metal centers in technologically and industrially important materials are unreceptive low-γ quadrupolar nuclei (i.e., possessing low natural abundance, low NMR frequencies and large quadrupole moments) and they usually give rise to very broad NMR resonances and low signal-to-noise ratios, making it difficult to acquire their solid-state NMR spectra. This thesis focuses on the characterization of inorganic materials using solid-state NMR (SSNMR) spectroscopy at very high magnetic field of …

Vaporization And Sublimation Enthalpies Of Acetanilide And Several Derivatives By Correlation Gas Chromatography, Patamaporn Umnahanant, James Chickos

James Chickos

No abstract provided.

Phosphine Sulfide Copper (I) Complexes: Effects On Oxygen Sensing Ability, Mary K. Walters

Antonian Scholars Honors Program

For many applications photoluminescence oxygen sensors are superior instruments compared to other commonly used techniques due to their use of a lumiphor’s emitted light intensity dependence on oxygen. Emitted light from a lumiphor in these sensors is quantitatively reduced by oxygen through quenching events caused by collisions of the lumiphor’s excited state with 3O2. The reduction in intensity upon exposure to oxygen is measured to determine ambient oxygen concentrations with great accuracy and precision. Though powerful instruments, photoluminescence oxygen sensors come with some problems including the use of expensive transition metal (Ru and Pt) lumiphors and polymer matrix supports prone …

The Impact Of Ligand Design On The Coordination Chemistry And Reactivity Of Metal Pincer Complexes, Sarath Wanniarachchi

Dissertations (1934 -)

Pincer ligands are uninegative tridentate metal-coordinating agents of the form [XZY]- where Z is the central, anchoring Lewis donor while X and Y are flanking Lewis donors. Ever since initial reports of transition metal pincer complexes were published in the late 1970's, there has been burgeoning interest in such complexes because of their desirable robust nature, generally simple syntheses, and the spectacular chemical transformations that they can mediate. In this research project, two new sets of pincer ligands with a diarylamido anchor and either two pyrazolyl nitrogenous flanking donors (NNN pincer) or one pyrazolyl and one diphenylphosphine donor (NNP pincer) …

Synthesis And Characterization Of Iron(Ii) Complexes Modeling The Active Site Structure Of Nonheme Iron Dioxygenases, Jacob Baus

Master's Theses (2009 -)

The aerobic degradation of polycyclic aromatic compounds, which are widespread contaminants in soils and groundwaters, is carried-out in large part by various Fe-containing dioxygenases that perform the cis-dihydroxylation and oxidative cleavage of aromatic rings. Recently, a new Fe dioxygenase family emerged that catalyzes a remarkable set of transformations; the distinguishing feature of these enzymes is that their monoiron(II) centers are coordinated by three histidines residues (i.e., imidazole ligands) in a facial geometry - a departure from the "canonical" 2-histidine-1-carboxylate facial triad that is dominant among nonheme monoiron enzymes. Members of the "3His family" are capable of oxidatively cleaving C-C bonds …

Optical And Electrochemical Properties Of Monolayer Protected Gold Clusters Modified With Fluorophores, Mary Sajini Devadas

Dissertations

My research focused on the synthesis, characterization and the investigation of the optical and electrochemical properties of monolayer-protected quantum-sized gold clusters. Significant research attention was focused on the solution phase optical and electrochemical properties of these clusters. Highly monodisperse Au clusters with different types of ligands were successfully synthesized with sizes varying from 1 nm to 13 nm. These preformed gold clusters were modified with fluorophores and pseudo-rotaxanes for developing better nonlinear optical materials for sensing and biological imaging purposes. We have tried to focus on the interaction of the outer ligand shell, made up of –S-Au-S-Au-S- bonds, with the …

Optical And Electrochemical Sensors For The Detection Of Metal Ions And Nerve Gas Mimics Via Fluorescein And Coumarin Derivatives, Fasil Adefris Abebe

Dissertations

Trace element detection of metals, for example, iron, Copper and zinc, are important in biological systems and in the environment. Many of us are aware that our cells contain metal ions that are “tied” up in proteins. However, chelatable or “free” trace elements can also be found in small quantities, and can have a negative impact on our bodies. Despite the increasing surge in developing sensors for metals and nerve gas agents, efficient detection still remains a challenge. Among the various sensors developed so far, fluorescence sensors play an important role due to their simplicity. I design fluorescein-based chemosensors for …

Investigation And Synthesis Of Novel Graphene-Based Nanocomposites For Hydrogen Storage, Anthony Joseph D'Angelo

USF Tampa Graduate Theses and Dissertations

It is of great interest to develop and utilize a high surface area material with optimized hydrogen sorption properties. The need for a renewable energy source to replace automobile gasoline has become more critical in the past decade. Hydrogen is a viable fuel source for automobile usage; however, the question of how hydrogen will be safely and efficiently stored still remains. Critical factors for optimum hydrogen storage include ambient conditions and low activation temperature for adsorption and desorption phenomena. In order for optimum hydrogen adsorption to be achieved, the properties of (1) high surface area, (2) optimum hydrogen adsorption energy, …