Digital Commons Network^™

Application Of Glycosyl Imidates And Nitrates In Carbohydrate Synthesis, Tinghua Wang

Dissertations

Carbohydrates are the most abundant molecules among the four essential classes of biomolecules that also include nucleic acids, lipids and proteins. Unlike proteins and nucleic acids, which follow template-driven synthetic pathways, there is no general route to the synthesis of carbohydrates. The stereoselectivity of the formation of O-glycosidic linkages and the regioselectivity of protection and deprotection of specific hydroxyl groups over others represent two of the major challenges in carbohydrate chemistry. This thesis is dedicated to the development of novel strategies for efficient synthesis of carbohydrate building blocks and stereocontrolled glycosylations for step-economy oligosaccharide synthesis. Novel glycosyl donors with difluoro-3H-indol-2-yl …

Investigation Of Vaporization Enthalpies And Vapor Pressures Of Organic Compounds By Correlation Gas Chromatography, Carissa Nelson

Dissertations

Thermodynamic properties of organic compounds are useful to scientists and manufacturers in many areas of research and technology. This work focuses on measuring and reporting these properties on materials of commercial, environmental and scientific interest. Vaporization enthalpies and vapor pressures of several organic compounds have been studied using correlation gas chromatography (CGC) and are reported here as well as in recent publications. The CGC method allows for the indirect measurement of these properties in instances where these materials are available only in mixtures or in very small amounts.

The qualities of these measurements for any chosen target are directly related …

Development Of Rules Of Attraction For Intercalated Guest Molecules Inside Of A Hydrogen Bonded Framework, Matthew Fischer

Dissertations

Supramolecular chemistry has synthesized large and small molecules which host guest molecules for several decades. What started as a way to mimic of enzymes in nature, has exploded into a sea of materials such as porous coordination polymers, low-density metal-organic frameworks, inclusion compounds, and hydrogen bonded frameworks. We previously designed a layered framework consisting of a metal complex with coordinate covalent ligands. These ligands have peripheral carboxylic acid groups which hydrogen bond to organic pillars containing terminal amines. The layered structure is separated by these pillars, which are closed-packed, creating 1-dimensional channels able to co-crystallize molecules. There is interest in …

Cationic Ruthenium Complexes In Catalysis: The Activation Of Propargylic Alcohols Through Electronically Tuned Complexes, Matthew James Stark

Dissertations

With increasing complexity of metal complexes, it is of worthwhile interest to pursue systematic examinations of ligand modifications to study their impact on the reactivity of a catalyst. To that end, this study aimed to understand the effect electron-withdrawing ligands conveyed to catalytic activity in the etherification of propargylic alcohols and related reactions. A number of half-sandwich ruthenium complexes bearing ligands with varying electron–withdrawing properties were synthesized and structurally characterized. Their electronic and structural properties were investigated utilizing X-ray crystallography, revealing that the series of complexes did not vary significantly in structure. The complexes were studied electronically with cyclic voltammetry, …

Steric Effects On The Formation Of Manganese Oxide Clusters And 2-Dimensional Ammonium Formate Architectures, Carl Oberle

Dissertations

It has been demonstrated by the Beatty group that altering the identity of the ortho-substituent of a dianiline counterion affects the assembly and dimensionality of a cadmium-chloride layer from 2-D to 0-D. This work seeks to extend this finding to metal oxide and organic hydrogen-bonded materials. By systematically increasing the ortho­-substituent’s size on the benzoate building block of reported manganese oxide clusters, of formula Mn_xO_y(O₂C-R)_zL_w (where R = Alkyl, L = neutral monodentate ligand), we aim to impact the self-assembly of these materials relative to their parent …

Chemical Synthesis Of Staphylococcal Oligosaccharides, Satsawat Visansirikul

Dissertations

The Gram positive, cluster forming bacteria Staphylococcus aureus belongs to the family of opportunistic pathogens that may cause blood stream infections when the integrity of skin is broken and the immune system can no longer fight the infection. S. aureus has become one of the most frequent causes of infections in newborns, surgical patients, trauma and burn patients, patients receiving an implant, and dialysis patients with high mortality rates. As a matter of fact, S. aureus has become one of the largest public health and economic impacts amongst all bacterial infectious diseases worldwide. This situation is further complicated by the …

Functionalized Nanoporous Carbon Scaffolds For Hydrogen Storage Applications, Christopher Carr

Dissertations

Recent efforts have demonstrated confinement in porous scaffolds at the nanoscale can alter the hydrogen sorption properties of metal hydrides, though not to an extent feasible for use in onboard hydrogen storage applications, proposing the need for a method allowing further modifications. The work presented here explores how the functionalization of nanoporous carbon scaffold surfaces with heteroatoms can modify the hydrogen sorption properties of confined metal hydrides in relation to non-functionalized scaffolds (FS). Investigations of nanoconfined LiBH₄and NaAlH₄indicate functionalizing the carbon scaffold surface with nitrogen can shift the activation energy of hydrogen desorption in excess of …