Physical Sciences and Mathematics Commons^™

Tantalum Carbene And Imide Complexes. Synthesis, Characterization, And Pathways Of Formation, Julia Kathryn Covington Abbott

Doctoral Dissertations

This dissertation focuses on two different types of organometallic compounds, carbenes and imides. The first project deals with the archetypal Schrock carbene, and the second project studies complexes that contain metal-nitrogen bonds, both amides and imides.

A summary of the research in this dissertation is discussed in Chapter 1. Chapter 2 begins the studies of the archetypal Schrock carbene (Bu^tCH₂)₃Ta=CHBu^t. The studies include the synthesis of deuterated compounds (Bu^tCD₂)₃TaCl₂ and Bu^tCD₂Li, observation and identification of the intermediate, Ta(CD₂Bu^{t …}

Synthesis, Functionalization And Characterization Of Dual Mode Nanoparticles For Biomedical Applications, Farah Radwan

Theses and Dissertations

Three different approaches were used to prepare dual mode nanoparticles using a previously described reverse micelle technique. Superparamagnetic Fe@FeOx core shell nanoparticles were chosen to be the magnetic component for all three dual mode systems. In the first type of particles, 2- amino-1,3- propane diol (APD) was used as a functionalization ligand to stabilize the surface of the particles and its functional amino group also provided a binding site for the attachment of a fluorescent probe. The TEM analysis showed that the APD coated particles have a size range of 8-13 nm while XPS and MALDI measurements confirmed the presence …

Dihydropyran Formation By A Two Step Process, James Zachary Wright

Undergraduate Honors Thesis Collection

The 2, 6-disubstitued dihydropyran is produced by a two step process, involving a Suzuki Miyaura Cross Coupling reaction followed by anintramolecular ring closing Michael Addition reaction. In this project a vinyl boronic acid, 6-(2-phenylethenyl)-2-hydroxy-I,2-oxaborole, was coupled with cis-ethyl-iodo-acrylate to yield ethyI 2E, 4Z, 8E-9-phenyl-7-hydroxy-2, 4, 8-nonatrienoate, which is capable of undergoing an intramolecular Michael addition to form the dihydropyran. The geometry of the cis enolate and the conjugated double bonds of the coupled product are such that under basic conditions a Michael addition is feasible. Throughout the project, the reaction conditions for high yields of Suzuki product were determined. Dihydropyrans …

The Development Of An Effective Water-Soluble Receptor For Pyrene Derivative Dyes, Ashley Longstreet

Undergraduate Theses and Capstone Projects

A receptor with enhanced water solubility was synthesized from an existing receptor to be used as a pyranine fluorescence quencher in endovesiculation detection assays. The existing receptor consisted of a cyclen core with four protruding arms containing an aryl nitro group at each end. Its poor water solubility limited the accuracy and precision of the endovesiculation assay because the low concentration of receptor did not match the concentration of pyranine. To increase the water solubility, ethoxy groups were attached to the ends of each arm by first selectively reducing the nitro group to an amine with NaBHU4, H2, and a …

Coordination Chemistry Of Tetra(Pyrazolyl)-Lutidine Ligands And Derivatives, Tyler James Morin

Dissertations (1934 -)

There is current interest in the coordination chemistry of simple AE4 pentadentate ligands that occupy one axial (A) and four equatorial (E) positions about a given transition metal center considering that systems capable of mediating spectacular organic transformations such as alkane oxidation have been identified. The discovery of new systems will improve understanding of C-H bond activation processes which is critical to help make more efficient use of the currently diminishing fossil fuel supplies. As such, a new pentadentate ligand α,α,α',α'-tetra(pyrazolyl)lutidine (pz4lut) and its derivatives pz4,4lut, (pz4, = 4-methylpyrazole); pz*4lut, (pz* = 3,5-dimethylpyrazole); pzDIP4lut, (pzDIP = 3,5-diisopropylpyrazole) have been synthesized …

Electrodeposited Silica Thin Films, Debbie Campbell-Rance

Theses and Dissertations

Sol-gel derived silica thin film synthesis has gained prominence because of the mild processing conditions and widespread understanding of the chemistry of the process. Traditionally, silicate films are prepared by spin- and dip-coating but these materials lack the desired porosity for sensing, separations and catalysis applications. Electrochemical deposition was proposed to improve the porosity of silicate films. The main aims of this work were threefold. First we wanted to elucidate what parameters influenced film formation during electrodeposition. Then we wanted to understand how these parameters affected the morphology of the materials prepared. These films were characterized by profilometry, AFM, and …

Study Of Drug Delivery Behavior Through Biomembranes Using Thermal And Bioanalytical Techniques, Hareesha Reddy Venumuddala

ETD Archive

This Master of Science thesis encompasses two projects in chemical pharmaceuticals. The first is a study of excipients and the added new information collected beyond Thermal Gravimetric Analysis and Differential Scanning Calorimetry from Dielectric Analysis. These new properties enhance our global knowledge of excipients by thermal analytical methods. Excipients, the inactive ingredients in formulated drugs, aid different functions of the active pharmacy ingredient, the drugs. Low temperature transitions, by DEA including melting of frozen solvents, e.g. water, are more definitive than observed by low temperature DSC. Millions of dollars are expended annually on pharmaceutical testing to qualify excipients for fully …

Progress Towards The Synthesis Of Type B Polycyclic Polyprenylated Acylphloroglucinol 7-Epi-Clusianone, Pushpa Suresh Jayasekara Mudiyanselage

University of Kentucky Doctoral Dissertations

Plants of the family Guttiferae produce polycyclic polyprenylated acylphloroglucinols (PPAPs), which have interesting biological activities including anticancer and antibacterial properties. The main structural features of PPAPs comprise of bicyclo[3.3.1]nonane-2,4,9-triketone with one acyl group together with prenyl, geranyl, or other C₁₀H₁₇ groups. 7-epi-Clusianone, a type B PPAP with C-7 endo stereochemistry, is being approached by establishing the cis relationship with C(4) allyl group and C(2) methyl ester in the early stage of the synthesis. Then C(2) methyl ester is converted to alkyne aldehyde and syn reduction followed by intramolecular aldol reaction to give bicyclo[3.3.1]nonane structure with …

Discovery And Identification Of New Dna Photoproducts And Investigation Of The Redox Mechanism Of Human Apurinic/Apyrimidinic Endonuclease 1 (Hape1) Protein, Dian Su

All Theses and Dissertations (ETDs)

Exposure of cells to ultraviolet light results in the formation of DNA photoproducts, many of which have been linked to skin cancer. The majority of these photoproducts arise from a photoreaction between two pyrimidines. Irradiation of double stranded B form DNA under physiological conditions mainly produces adjacent dimers. Nonadjacent photodimers of both intrastrand and interstrand types are much rarer. Intrastrand-type nonadjacent dimers form when one or more nucleotides between two pyrimidines become extrahelical owing to the formation of single strand DNA or a slipped structure. This allows the two pyrimidines to photodimerize in a colinear arrangement, as if the intervening …

Functionalized, Semicrystalline Poly(Ether Ketone)S Via In Situ Modification Chemistry, Raghavendhar Reddy Kotha

Browse all Theses and Dissertations

AB3 monomer (3,4,5-Trifluoro-4'-hydroxybenzophenone) was used for polymerizations in order to mimic the combination of AB and AB2 monomers, and which has potential to facilitate concurrent polymerization and functionalization. 'Pre' and 'post' polymerization functionalization of the PEK system was done using phenol, 4-bromophenol, and 3/4-aminophenol. The solubility of the functionalized polymers was increased; and the crystallinity was decreased significantly compared to the corresponding unfunctionalized homopolymer. The polymers were characterized by 1H and 13C NMR spectroscopy, Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC). DSC results showed that the crystallinity of the polymer was tuned by the amount …

Routes To Sydno[3,4-A]Quinoxalines, Erik Dihrkop

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In the present work, the reactivity of alkyl and aryl sydnoquinoxalines was studied. Using a previously developed method, triphenylphosphine-2-(3-sydnonyl)phenylimide was prepared in a two-step process via a diazotization / azidation process of 3-(2-aminophenyl)sydnone, followed by treatment with triphenylphosphine. Due to the inability to achieve previously reported yields, a new, one-step method using Mitsunobu conditions was employed to synthesize the iminophosphorane in a good yield. A similar, brominated iminophosphorane was synthesized using the same conditions in a good yield. Treatment of both the brominated and non-brominated iminophosphoranes with alkyl and aryl isocyanates or isothiocyanates in an aza-Wittig process, gave the corresponding …