Metal-oxo clusters are discrete, soluble pieces of bulk metal oxide. Cluster size, monodispersity, and chemical properties allow for potential use as solution-based precursors for functional metal oxide films. Classical monoalkyltin-oxo clusters are either charge neutral or stabilized by anions. The structure of Cs₄.₅H₂.₅[(BuSn)₃(α-SiW₉O₃₇)]*2H₂O enables its use in established ion exchange...
Metal-oxo clusters can be described as soluble pieces of metal-oxide frameworks. Currently, metal-oxo clusters are being considered as solution-based precursors for extreme ultraviolet (EUV, 13.5 nm) photoresist materials, which are a crucial component in the fabrication of microelectronic devices. Two different photoresist precursor systems have been investigated – alkyltin clusters...
Naturally occurring assemblies, such as DNA and proteins, utilize intermolecular forces (i.e H-bonding and van der Waals) to assemble. Utilizing these electrostatic interactions has only just started in the past five decades to be a tool used in synthetic chemistry in what is known as supramolecular chemistry. Supramolecular chemistry has...
Iron oxide materials including ferrihydrite and magnetite play essential roles in contaminant transport, pH control of surface and groundwater, and microbial activity. They have various applications ranging from data storage to cancer therapy. Recent studies showed that the NPs growth does not involve atom by atom nucleation but starts by...
Frontier research of non-aqueous actinide clusters is discussed. Since the inception of the uranyl peroxide clusters over the last decade, they have only been synthesized and characterized as solid crystals and in aqueous solution. This thesis provides thorough characterization of aqueous uranyl clusters and the first demonstration of uranyl cluster...
Polyoxometalates are a rapidly growing class of discrete metal oxide clusters with a wide range of applications including functional materials. These anionic clusters of the group V and VI transition metals are inexpensive and non-toxic. Within group V polyoxometalates, niobium and tantalum chemistry has been underdeveloped owing to their unique...
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May Nyman
Polyoxometalates are a rapidly growing class of discrete metal oxide clusters
Metal-oxo clusters can be described as soluble pieces of metal-oxide frameworks. Metal-oxo clusters are also the building blocks for the Metal-Organic Frameworks (MOFs) and coordination polymers. A better knowledge of metal-oxo clusters helps fundamentally understand geosciences, molecular engineering, catalysis, single-molecule magnetism, and MOFs for synthesis, design, and modification of these...
Polyoxometalates (POMs) are anions consisting of three or more early transition metals ™ (Gr V and VI) oxoanions (in their highest oxidation state) linked together by a shared oxygen bond to form a 3D framework. Polyoxometalates (POMs) are a rapidly growing class of metal oxo clusters with a wide range...
A molecular approach to metal oxides allows to the study to fundamental bonding and formation behavior for such metals. Moreover, the molecular nature of such oxides or metal-oxo clusters allows the possibility of exploitation of the properties of the parent oxides. The tetravalent metals, in specific, (M=Zr, Hf, Ce, Th,...
Uranyl peroxide clusters are the newest family of polyoxometalates, discovered in 2015. Although this family is new, over 70 topologies have been reported. However, we lack the fundamental understanding of assembly mechanisms, particularly the role of the alkali countercations. Here, we use a wide range of solution and solid-state characterization...
Polyoxometalates are discrete anionic oxo clusters of the Group V and VI transition metals that can be conceptualized as molecular metal oxides. Because they are pairable with any alkali cation, a great deal of fundamental chemistry can be gleaned from their study, including solubility trends and insight into cation binding...
Metal-oxo clusters are discrete molecular metal-oxides. Most metals form numerous cluster compounds that can be ligated, unligated, charged or neutral, controlling their solubility in water and/or organic solvents. They are important species to study reaction pathways from the monomeric building units to the bulk metal oxides, and have many application...
Polyoxoniobates (PONbs) are attracting great attention in recent years due to its novelty as well as a variety of geometrical presentations in different pH conditions. In this paper we are reporting the reaction of tetramethyl-decaniobate ([(CH3)4N]6[Nb10O28]) with alkaline carbonates to observe the periodic trend of alkaline ions interacting with the...
Lycopodium alkaloids have generated enormous amounts of interest from the scientific community, both as synthetic targets and for their medicinal properties. Herein is described work towards a unifying approach to large segments of the Lycopodium family. An organocatalyzed intramolecular heteroatom Michael reaction method, for the construction of piperidine and piperizine...
In this dissertation, the process of computational modeling of amorphous oxide materials is studied. Amorphous oxides have random atomic arrangements with no long-range structural order which makes it difficult to study structure-property relationships. Despite the difficulties, amorphous oxides have great uses as semiconductors and dielectrics in thin-film transistors. The ability...
Discrete aqueous metal oxide polyionic clusters that include aluminum polycations, transition-metal polyoxometalates, and the actinyl peroxide clusters have captivated the interest of scientists in the realm of both their fundamental and applied chemistries. Yet the counterions for these polycations or polyanions are often ignored, even though they are imperative for...
While the d⁰ transition-metal POMs of Group V (V⁵⁺, Nb⁵⁺, Ta⁵⁺) and Group VI (Mo⁶⁺, W⁶⁺) have been known for more than a century, the actinyl peroxide POMs, specifically those built of uranyl triperoxide or uranyl dihydroxidediperoxide polyhedra, were only realized within the last decade. While virtually every metal on...
Oxo-hydroxo Group 5 metal clusters are an untapped resource to study and advance aqueous solution processing of metal oxide thin films. The tetramethylammonium (TMA) hexatantalate salt (TMA6[H2Ta6O19]) yields dense Ta2O5 films (~95% of the bulk ß-Ta2O5 density) with atomically smooth surfaces (<4 Å root mean square surface roughness). This same...
Novel graphite intercalation compounds (GICs) and associated chemistry have been explored, specifically: (1) containing alkyl- substituted imidazolium cations; (2) a series containing alkaline earth metal (Mg, Ca, Sr, Ba) cations with ethylenediamine (en) co-intercalates; (3) showing reversible intragallery M-M bonding and (4) via electrochemical intercalation of Mg cations with potential...
Porous carbon is indispensable in modern technology applications. It is used for energy storage, gas separation, water purification, catalyst support, and chromatography. The diversity of its applications stems from its unique properties, including high specific surface area, tunable pore volume, and chemical stability. Specifically, the large surface area provides high...
Studies towards the total synthesis of (+)-Phomactin A (1), D (6), and G (9), fungal metabolites with unique molecular architecture and pronounced biological activity, are described. These studies resulted in the synthesis of advanced intermediates 354 and 356, which contain all of the carbon atoms of 1, 6 and 9....
Grid-scale energy storage systems are urgently needed to increase the flexibility and rigidity of the grid for modern society and take full advantage of the renewable green energy resources such as solar energy and wind energy. Na-ion batteries (NIBs) and K-ion batteries (KIBs) have been emerged as one of the...
Phosphate and peroxide stabilize new oxo-hydroxo niobium clusters in water at low pH. The clusters open a new chapter in aqueous niobium chemistry under acidic conditions. The clusters also produce atomically smooth, amorphous niobium oxide phosphate (NbPOx) thin films. Reaction pathways from cluster solutions to amorphous niobium oxide phosphate solids...
The continued long-term use of fossil fuels as a primary energy source has resulted in dramatic increases in greenhouse gas emissions and the associated concerns of climate change and environmental pollution. A key strategy to circumvent these issues is a global shift away from fossil fuels toward renewable energy sources....
In the 21st century, environmental deterioration is now an indisputable fact. Reliable and economically viable electricity systems based on renewable sources are urgently needed to replace the environmentally detrimental fossil fuels. The feasibility of incorporating renewable-but-intermittent solar and wind energy heavily depends on the development of cost-effective and safe technologies,...
Electrochemical capacitors and batteries are two major electrochemical energy storage technologies, which have been investigated extensively to meet the rapidly-growing demand for higher energy, higher power, lower cost and enhanced safety in the past few decades. With the charge storage mechanism of electrostatic charge adsorption desorption via electrical double layers,...
Novel donor-typed ternary graphite intercalation compounds (GICs) are synthesized and characterized containing (1) pyrrolidinium cations with DMSO co-intercalates; (2) alkali metal cations with crown ether co-intercalates; and (3) alkali metal cations with polyethylene glycol co-intercalates. Structural and compositional data are obtained for the stable products. A new ether-amine co-intercalate exchange...
Chemistry of preparing dense film from solution deposition is explored with several cases in this thesis. Surface dense structure, conversion at melting point, and ion exchange in aqueous solution are the main topics covered here for the thin films of aluminum oxide phosphate and tin dioxide. Thin film density, optical...
As scientists, we have an affinity for order: repeating crystal structures, Euclidean space, continuous functions… Even concepts such as defects are discussed in the context of distracting from order. Things are most logical and best described in straightforward, taxonomical fashion. But what happens when the very application desired is dependent...
In this dissertation, the structural properties, thermodynamics and defect behavior of amorphous metal oxides and polyoxometalates are studied. Amorphous metal oxides have many applications, most notably as a semiconducting material used as the active matrix of thin film transistors. Alas, the amorphous nature of these materials makes studying them rather...
Inorganic structures play an important role in materials due to their versatility and diversity. A complete understanding of the structure of a material is vital to enhance the creation of new materials that fill voids in research. The rational design of these compounds is driven by the exploitation of structure-property...
Pyroprocessing is an advanced technology for recycling used nuclear fuel. Pyrochemical processes encompass a wide range of chemical, physical, and electrochemical methods to partition fission products and other components from used nuclear fuel, which allows for the reuse of the actinides in nuclear fuel. This dissertation investigates two chemical systems...
Aseptic radiorespirometry has been used to examine
the utilization of external carbon sources by proliferating
Thiobacillus thioparus cells. These studies reveal
that glucose, galactose, mannose, fructose, ribose, DL-glutamate,
and L-aspartate were not utilized by this
chemoautotrophic organism. However, it has been shown
that trace amounts of acetate, glycine, DL-serine, DL-alanine,...
This dissertation is separated into two parts according to the two major distinct research projects. In Part I, the full account of synthetic studies toward C10-functionalized lycopodium alkaloids is described. In Part II, the detailed discussion on the exploration of the Pummerer cyclization methodology and its application to the total...
The enantioselective total synthesis of quinolizidine-containing natural product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These natural products are members of the lycopodium alkaloids, which have attracted significant attention due to their exciting biological activities and the diverse structural scaffolds. Key steps in...
More than 30 members of the diverse amphidinolide family of biologically active macrolides have been isolated over last three decades. From this family, amphidinolides C and F stand among the most complex and densely functionalized affiliates. Recently, we have accomplished the first total synthesis of amphidinolide F. The all-carbon framework...
Ion pairs and solubility related to ion-pairing in water influence many processes in nature and in synthesis including efficient drug delivery, contaminant transport in the environment, and self-assembly of materials in water. Ion pairs are difficult to observe spectroscopically because they generally do not persist unless extreme solution conditions are...
Lycopodium alkaloids have shown widespread and noteworthy biological activity, consisting of over 250 known natural products. Moreover, their structural complexity and diversity have attracted considerable attention from numerous laboratories including our own. Recently, we have developed a unified approach that would provides access to numerous, previously unprepared C₁₀-functionalized lycopodium alkaloids....
Part I of this dissertation includes the chronological synthetic background of mandelalide A as well as the synthesis of the C1-C14 glycosylated southern subunit of mandelalide. A key aspect of the synthesis includes a novel silver-catalyzed cyclization (AgCC) of a propargylic benzoate to construct the substituted cis-pyran ring system present...
Effective methods for the enantiopure formation of substituted piperidine rings are significantly important due to their presence in alkaloid products. A valuable method to form these ring systems would be via an intramolecular heteroatom Michael addition from the corresponding enone or enal. Described herein is a methodolgy that has been...
A Diels-Alder approach to biaryls (DAB) has been applied towards the synthesis
of highly substituted, programmable biaryl templates. Tri- and tetra-ortho-substituted
biaryls can be produced in just three to four steps from commercially available materials
utilizing the Diels-Alder [4+2] cycloaddition. The methods described herein will
illustrate the ability of mono...
An expedient approach to the synthesis of a wide range of highly programmable biaryl templates has been accomplished. Utilizing the Diels-Alder [4+2] cycloaddition, a wide range of tri- and tetra-ortho-substituted biaryls have been synthesized in only three to four steps from commercially available materials. We have successfully synthesized entire classes...
Mandelalide A has attracted considerable interest from the synthetic community due to its intriguing structure and important cytotoxic activity. Madeirolide A, a structurally related macrolide, shows promising antifungal activity but no appreciable anticancer activity. This dissertation describes synthetic studies toward mandelalide A, madeirolide A and their hybrid structures.
Part I...