Chemistry Commons^™

Structure-Function Relationships In Poly(3-Hexylthiophene)S Formed Via Manipulation Of Oxidative Coupling Routes, Warren James Solfiell

LSU Doctoral Dissertations

This investigation focused on the analytical characterization of poly(3-hexylthiophene), a heterocyclic conducting polymer system, with an overall objective of elucidating the effects that the experimental conditions during chemical oxidation using iron(III) chloride as an oxidant impart on the structure of the resulting polymers. Poly(3-alkylthiophene)s are extensively studied materials due to their high electrical conductivities and unique optical properties that make them extremely valuable for use in contemporary technological applications and devices. Specifically, the aim of this research was to determine the dependence of structural characteristics, such as endgroups, molecular weights, and regioregularities, on the solvent employed for the reaction and …

Analysis Of Amyloid Beta (A [Beta]) Peptides By Capillary Electrophoresis And Laser-Induced Fluorescence Anisotropy Detection, Ryan Andrew Picou

LSU Doctoral Dissertations

The goal of the research presented in this dissertation is to develop laser-induced fluorescence anisotropy (LIFA) detection for detecting and characterizing amyloid beta (Aβ) peptide aggregates separated by capillary electrophoresis (CE). Senile plaques composed primarily of aggregated Aβ (1-40) and Aβ (1-42) peptides have been found in the brains of Alzheimer’s disease patients. These peptides are thought to be responsible for the disease pathology. A CE method using UV absorbance detection was developed for the quantification of Aβ (1-40) monomer and testing of Aβ monomer preparations for undesired aggregates (Chapter 2). Analyses of both Aβ (1-40) and Aβ (1-42) monomer …

Formation And Stabilization Of Combustion-Generated Environmentally Persistent Free Radicals On Transition Metal Oxides Supported On Silica, Eric Warren Pimentel Vejerano

LSU Doctoral Dissertations

The formation of environmentally persistent free radicals in combustion system was investigated from chemisorptions of chlorine- and hydroxy-substituted benzenes on transition metal oxide surface under post-combustion conditions. This manuscript reports the formation of EPFRs on silica particles containing 5% Fe(III)2O3, Ni(II)O, and Zn(II)O. The EPFRs are formed by the chemisorption of substituted aromatic molecular adsorbates on the metal cation center followed by electron transfer from the adsorbate to the metal ion at temperatures from 150 to 400 oC. Depending on the nature of the adsorbate and the temperature, two organic EPFRs were formed: a phenoxyl-type radical, which has a lower …

Microwave-Induced Bismuth Nitrate-Mediated Selective Hydrolysis Of Amide, Debasish Bandyopadhyay, Rene Solano Fonseca, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Microwave-induced selective hydrolysis of amide to the corresponding amine has been achieved with bismuth nitrate and montmorillonite KSF clay.

An Easy And Straightforward Route For The Synthesis Of Disubstituted Imidazoles, Debasish Bandyopadhyay, Yvette Mora, Jesus A. Trevino-Cantu, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

A simple and high-yielding procedure has been developed to synthesize disubstituted imidalozes using phenyl glyoxal monohydrate, ammonium acetate and aldehydes. This synthetic protocol allows the preparation of a variety of 2,4 (s)-disubstituted imidalozes without using any catalyst, expensive or sensitive reagents. A corresponding 2-aroyl-4(s) disubstituted imidalozes derivative has also been isolated as byproduct. The effects of solvents have also been studied.

Microwave-Induced Bismuth Nitrate-Catalyzed Electrophilic Substitution Of 7-Aza Indole With Activated Carbonyl Compound Under Solvent-Free Conditions, Sonya Rivera, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

An expeditious microwave-induced synthetic method for the preparation of bis(azaindollyl)methane derivative has been developed through a bismuth nitrate-catalyzed reaction of 7-azaindole with diethylketomalonate under solvent-free conditions.

Microwave-Induced N-Bromosuccinimide-Mediated Novel Synthesis Of Pyrroles Via Paal-Knorr Reaction, Rosemarie Andoh-Baidoo, Roberto Danso, Sanghamitra Mukherjee, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

An expeditious rapid synthesis of N-substituted pyrroles using microwave-induced Nbromosuccinimide- mediated solventless reaction of 2,5-hexanedione and primary amine has been accomplished.

Microwave-Induced Bismuth Nitrate-Catalyzed Electrophilic Substitution Of Indole With Keto Ester Under Slovent-Free Conditions, Sonya Rivera, Laura Iglesias, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Microwave-induced preparation of bis(indollyl)methane derivative has been developed through a bismuth nitrate-catalyzed reaction of indole with diethylketomalonate under solventfree conditions.

Microwave-Induced Indium-Catalyzed Synthesis Of Pyrrole Fused With Indoline In Water, Dina Abrego, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

An expeditious microwave-induced indium metal-catalyzed synthesis of pyrrole fused with indoline in water is developed by reacting isatin and 4-hydroxyproline.

Microwave-Induced Bismuth Nitrate-Catalyzed Expeditious Enamination Of Β-Dicarbonyl Compounds Under Solvent-Free Conditions, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Bismuth nitrate-catalyzed, automated microwave-assisted expeditious synthesis of β- enaminones and β-enaminoesters has been carried out in an efficient manner under solvent-free condition. The reaction is general for primary, secondary (cyclic, heterocyclic and acyclic), benzylic as well as aromatic amines.

Antimicrobial Activity Of Eugenol Derivatives, George Eyambe, Luis Canales, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The antibacterial properties of the clove plant are due to the presence of eugenol, an aromatic phenolic compound. Eugenol was isolated from clove by stem distillation. The alkene group in eugenol was epoxidized resulting in the synthesis of epoxide-eugenol. The heterocyclic ring in epoxide was cleaved to a bromoalcohol derivative. The compounds synthesized epoxideeugenol, bromo alcohol and euginol were tested for antimicrobial activity against Staphylococcus aureus (ATCC 25923). Epoxide-eugenol was found to be the most effective antimicrobial agent among the three compounds tested.

Phosphoric Acid Catalyzed Aza-Michael Reaction In Water: An Ecofriendly Procedure, Debasish Bandyopadhyay, Stephanie Maldonado, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Phosphoric acid catalyzed aza-Michael reaction in water has been carried out in an efficient manner at room temperature. The reaction is general for primary, secondary (cyclic, heterocyclic and acyclic), benzylic as well as aromatic amines. No bis-addition was observed for primary amines.

Sythesis Of Glucose Peracetate Via Bismuth Nitrate-Induced Reaction, Jose Lerma, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Simple synthesis peracetylated glucose has been achieved starting from glucose and acetic anhydride in the absence of solvent via bismuth nitrate-catalyzed reaction. This method does not need large excess of acetic anhydride.

Microwave-Induced Stereoselectivity Of Β-Lactam Formation: Effects Of Solvents, Debasish Bandyopadhyay, Marco Yanez, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Synthesis of 3, 4-disubstituted 2-azetidinones has been achieved following Staudinger reaction under microwave-induced conditions. The stereoselectivity of β-lactam formation depends on the nature of the solvents used in the reaction.

Application Of Scanning Probe Microscopy For New Physical Measurements And Studies Of Surface Chemical Reactions Of Materials At The Molecular Level, Stephanie Loletha Daniels

LSU Doctoral Dissertations

Scanning probe microscopy (SPM) provides unique capabilities for surface visualization and measurements that reach atomic and molecular dimensions. My research focus is directed toward applying and developing new measurements for analytical and surface chemistry with SPM. Two distinct goals based on studies with atomic force microscopy (AFM) will be described within this dissertation. The primary goal was to develop and apply a new AFM imaging mode for ultrasensitive measurements of the superparamagnetic properties of proteins. Magnetic sample modulation (MSM)-AFM, has capabilities to investigate and map the magnetic response of nanomaterials with unprecedented spatial resolution. The second goal was to apply …

Exotic Ground States: A Study In The Structural Effects On Frustration And Dimensionality, Melissa C. Menard

LSU Doctoral Dissertations

Structural disorder and dimensionality play central roles in the characterization of structure and properties of crystalline materials. Although structural disorder is commonly considered an undesirable quality, structural disorder may be desirable when searching for new materials with exotic properties. Disorder can be used as a tunable parameter when considering atomic sizes, coordination preferences, and electronegativity differences can be varied by substituting elements into a given structure. Dimensionality can be viewed as another adjustable parameter when searching for new materials presenting unique challenges when characterizing new materials. One way to tune dimensionality is by chemical doping to affect coupling between layers/chains. …

Probing Molecules In Confined Space, Carissa Marie Vetromile

USF Tampa Graduate Theses and Dissertations

Despite the plethora of information regarding cellular crowding and its importance on modulating protein function the effects of confinement on biological molecules are often overlooked when investigating their physiological function. Recently however, the encapsulation of biomolecules in solid state matrices (NafionTM, sol-gels, zirconium phosphate,etc.) has increased in importance as a method for examining protein conformation and dynamics in confined space as well as novel applications in biotechnology. Biotechnological applications include, but are not limited to, bioremediation, biosensors, biocatalysts, etc. In order to better utilize solid state materials as substrates for biological molecules an understanding of the effects of encapsulation on …

Water-Soluble Bis(1,10-Phenanthroline) Octanedioate Cu2+ And Mn2+ Complexes With Unprecedented Nano And Picomolar In Vitro Cytotoxicity: Promising Leads For Chemotherapeutic Drug Development, Andrew Kellett, Mark O'Connor, Malachy Mccann, Orla Howe, Alan Casey, Pauraic Mccarron, Kevin Kavanagh, Mary Mcnamara, Sean Kennedy, Donald May, Philip Skell, Denis O'Shea, Michael Devereux

Articles

Dinuclear Cu^II and Mn^II bis-phenanthroline octanedioate complexes exhibit rapid, unprecedented nano and picomolar in vitro cytotoxicity against colorectal cancer lines and are less toxic than cisplatin when examined in vivo. The complexes are potent generators of cellular reactive oxygen species, avid DNA binders and induce O₂ dependent cleavage of DNA. The Cu(II) complex was found to have self-cleaving nuclease activity.

Evaluation Of The Physicochemical Properties And Stability Of Solid Lipid Nanoparticles Designed For The Delivery Of Dexamethasone To Tumors, Melissa Howard

University of Kentucky Doctoral Dissertations

Pre-clinical and clinical trials suggest that pre-treatment with dexamethasone (Dex) may facilitate enhanced uptake of subsequently administered chemotherapeutic agents. To reduce the side effects associated with systemic administration of Dex, solid lipid nanoparticles (SLNs) containing dexamethasone palmitate (Dex-P) were prepared as a means of achieving tumor-targeted drug delivery. These studies were aimed at evaluating the physicochemical properties and both the physiological and storage stability of the SLNs.

SLNs were prepared using nanotemplate engineering technology. Stearyl alcohol (SA) was used as the lipid phase with Brij^® 78 and Polysorbate 60 as surfactants and PEG6000 monostearate as a long-chain PEGylating agent. …

Inducible Nitric Oxide Synthase Provides Protection Against Injury-Induced Thrombosis In Female Mice, Rita K. Upmacis, Hao Shen, Lea Esther S. Benguigui, Brian D. Lamon, Ruba S. Deeb, Katherine A. Hajjar, David P. Hajjar

Faculty Papers and Publications

Nitric oxide (NO) is an important vasoactive molecule produced by three NO synthase (NOS) enzymes: neuronal (nNOS), inducible (iNOS) and endothelial NOS (eNOS). While eNOS contributes to blood vessel dilation that is generally thought to protect against the development of hypertension, iNOS has been primarily implicated as a disease-promoting isoform leading to protein-bound 3-nitrotyrosine formation in aortic lesions and select organs during atherogenesis. Despite this, iNOS may also play a physiological role, via the modulation of cyclooxygenase and thromboregulatory eicosanoid production. Herein, we examined the role of iNOS in a murine model of thrombosis. Blood flow was measured in carotid …

A Different Kind Of Garden: Seeding The Growth Of Tas2 Nanostructures With 3d Transition Metals, Kayla Rose Boyle

Honors Program Theses

An investigation into the synthesis of TaS₂ nanostructures was performed through the comparison of four growth methods. Each method utilized a 3d metal, Mn or Cr, or a comparable metal sulfide compound as a potential nucleating compound to seed the growth of these nanostructures, and all samples were produced using similar heating conditions. Sample imaging of the final products was performed using scanning electron microscopy (SEM), while the chemical compositions were determined by x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS). From these analyses it was determined that the most effective growth process for these TaS2 nanostructures resulted …

Growth And Characterization Of Nanoscale Thin Films, Erik Thomas Wolter

Honors Program Theses

Thin manganese films were grown by thermal evaporation in high vacuum. The growth rate was varied to determine how the growth rate affects the continuity of ultra-thin films. The resistance was measured with the two-point method in situ and the data was recorded digitally. The resistance was converted to resistivity and this was plotted against thickness. It was found that resistivity decreases exponentially as the film begins to form in islands. The film reaches a critical thickness as the islands coalesce and the data can then be fitted with Fuchs’ equation. The resistivity continues to decrease but the minimum resistivity …

Changes In Apparent Molar Water Volume And Dkp Solubility Yield Insights On The Hofmeister Effect, Daryl K. Eggers, A. Y. Payumo, R. M. Huijon, D. D. Mansfield, L. M. Belk, A. K. Bui, A. E. Knight

Faculty Publications, Chemistry

This study examines the properties of a 4 × 2 matrix of aqueous cations and anions at concentrations up to 8.0 M. The apparent molar water volume, as calculated by subtracting the mass and volume of the ions from the corresponding solution density, was found to exceed the molar volume of ice in many concentrated electrolyte solutions, underscoring the nonideal behavior of these systems. The solvent properties of water were also analyzed by measuring the solubility of diketopiperazine (DKP) in 2.000 M salt solutions prepared from the same ion combinations. Solution rankings for DKP solubility were found to parallel the …

Steps Toward Accurate Large Area Analyzes Of Genesis Solar Wind Samples: Evaluation Of Surface Cleaning Methods Using Total Reflection X-Ray Fluorescence Spectrometry, Martina Schmeling, Donald S. Burnett, Amy Jg Jurewicz, Igor V. Veryovkin

Chemistry: Faculty Publications and Other Works

Total reflection X-ray fluorescence spectrometry (TXRF) was used to analyze residual surface contamination on Genesis solar wind samples and to evaluate different cleaning methods. The Genesis mission collected solar wind during a period of 854 days by embedding the charged particles into collectors made of various ultra clean materials such as silicon, sapphire and silicon-on-sapphire. The sample return capsule unexpectedly crashed on return to Earth fracturing the collectors and exposing them to the desert soil of the landing side. The ubiquitous contaminants are separated from the atoms of solar wind by only 5-15 nm, presenting significant challenges for solar wind …

Precise Control Of Highly Ordered Arrays Of Nested Semiconductor/Metal Nanotubes, Diefeng Gu, Helmut Baumgart, Kandabara Tapily, Pragya Shrestha, Gon Namkoong, Xianyu Ao, Frank Müller

Electrical & Computer Engineering Faculty Publications

Lithographically defined microporous templates in conjunction with the atomic layer deposition (ALD) technique enable remarkable control of complex novel nested nanotube structures. So far three-dimensional control of physical process parameters has not been fully realized with high precision resolution, and requires optimization in order to achieve a wider range of potential applications. Furthermore, the combination of composite insulating oxide layers alternating with semiconducting layers and metals can provide various types of novel applications and eventually provide unique and advanced levels of multifunctional nanoscale devices. Semiconducting TiO₂ nanotubes have potential applications in photovoltaic devices. The combination of nanostructured semiconducting materials …

Diffusion And Random Walks, Lewis Ludwig, Annabel Edwards

Faculty Publications

No abstract provided.

Alteration Of Hydrogen Bonding In The Vicinity Of Histidine 48 Disrupts Millisecond Motions In Rnase A, Nicolet Doucet, Gennady Khirich, Evgenii L. Kovrigin, J. Patrick Loria

Chemistry Faculty Research and Publications

The motion of amino acid residues on the millisecond (ms) time scale is involved in the tight regulation of catalytic function in numerous enzyme systems. Using a combination of mutational, enzymological, and relaxation-compensated ¹⁵N Carr−Purcell−Meiboom−Gill (CPMG) methods, we have previously established the conformational significance of the distant His48 residue and the neighboring loop 1 in RNase A function. These studies suggested that RNase A relies on an intricate network of hydrogen bonding interactions involved in propagating functionally relevant, long-range ms motions to the catalytic site of the enzyme. To further investigate the dynamic importance of this H-bonding network, this …

Direct Patterning Of A Cyclotriveratrylene Derivative For Directed Self-Assembly Of C60, Zachary R. Osner, Dorjderem Nyamjav, Richard C. Holz, Daniel P. Becker

Chemistry Faculty Research and Publications

A novel apex-modified cyclotriveratrylene (CTV) derivative with an attached thiolane-containing lipoic acid linker was directly patterned onto gold substrates via dip-pen nanolithography (DPN). The addition of a dithiolane-containing linker to the apex of CTV provides a molecule that can adhere to a gold surface with its bowl-shaped cavity directed away from the surface, thereby providing a surface-bound CTV host that can be used for the directed assembly of guest molecules. Subsequent exposure of these CTV microarrays to C₆₀ in toluene resulted in the directed assembly of predesigned, spatially controlled, high-density microarrays of C₆₀. The molecular recognition capabilities …

The Synthesis, Characterization, And Upconverting Properties Of Erbium Doped; Ytterbium, Erbium Co-Doped Yttrium Oxysulfide Phosphors Under 808, 980, And 1560 Nm Excitation, James Wilkins

Theses and Dissertations

Bulk yttrium oxysulfide phosphors were prepared using the polysulfide flux method. The morphology and structure was characterized using transmission electron microscopy and x-ray powdered diffraction. Visible emissions occurring near 530 and 550 nm and 660 - 670 nm consistent with the 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions, respectively, were observed under 808, 980, and 1560 nm excitation. The upconverting mechanisms excited at 808, 980, and 1560 nm have been investigated in detail. The power dependent behavior of the upconverted emission intensities for singly doped erbium phosphors excited at 808 and 980 nm indicated a two-photon excitation process. …

Recent Advances In The Synthetic And Mechanistic Aspects Of The Ruthenium-Catalyzed Carbon-Heteroatom Bond Forming Reactions Of Alkenes And Alkynes, Chae S. Yi

Chemistry Faculty Research and Publications

The group’s recent advances in catalytic carbon-to-heteroatom bond forming reactions of alkenes and alkynes are described. For the C–O bond formation reaction, a well-defined bifunctional ruthenium-amido catalyst has been successfully employed for the conjugate addition of alcohols to acrylic compounds. The ruthenium-hydride complex (PCy₃)₂(CO)RuHCl was found to be a highly effective catalyst for the regioselective alkyne-to-carboxylic acid coupling reaction in yielding synthetically useful enol ester products. Cationic ruthenium-hydride catalyst generated in-situ from (PCy₃)₂(CO)RuHCl/HBF₄·OEt₂ was successfully utilized for both the hydroamination and related C–N bond forming reactions of alkenes. For …