Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons

Open Access. Powered by Scholars. Published by Universities.®

Louisiana State University

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 301 - 330 of 619

Full-Text Articles in Chemistry

Silica Polypeptide-Based Colloids: Physical Properties And Novel Materials, Cornelia Rosu Jan 2013

Silica Polypeptide-Based Colloids: Physical Properties And Novel Materials, Cornelia Rosu

LSU Doctoral Dissertations

The investigation of polypeptide composite particles, PCPs, is described. The production of mesoporous and polycolloid architectures is also addressed. PCPs were prepared by both growing form and grafting to method. They consist of a core made of silica, silica-coated magnetite or silica-coated cobalt. Some of the particles were covalently labeled with fluorescein isothiocyanate. Several polypeptides were chosen for attachment on the core: poly(γ-stearyl-L-glutamate), PSLG, poly(Nε-carbobenzyloxy-L-lysine), PCBL and poly(o-benzyl-L-tyrosine), PBTY. Attachment of a well-characterized alkyne-end terminated PSLG and PCBL to an azide- functionalized particle yielded PCPs with a desired sparse coverage. A blend of techniques such as FTIR, XPS, TEM, HTEM, …


Investigations Into Alkene Hydration And Alkene Oxidation Catalysis, William Schreiter Jan 2013

Investigations Into Alkene Hydration And Alkene Oxidation Catalysis, William Schreiter

LSU Doctoral Dissertations

Bimetallic Ni complexes Ni21M and Ni21R and monometallic transition metal complexes were investigated as possible alkene hydration catalysts under a multitude of different reaction conditions. All attempts at performing this catalytic reaction failed to give any alcohol products. Catalytic screening experiments were conducted using a mixture of racemic-et,ph-P4 and meso-et,ph-P4, 1M and 1R, and various transition metals. These experiments gave several different products including 1-phenylethanol from styrene. During the course of the hydration experiments, an aldehyde product was identified from experiments conducted with the bimetallic complexes in air. Experiments have shown that the aldehyde is produced from the oxidative cleavage …


Synthesis, Characterization And Biological Studies Of Carboranyl-Porphyrin Bioconjugates For Treatment Of Brain Tumors, Naga Venkata Satya Dinesh Kumar Bhupathiraju Jan 2013

Synthesis, Characterization And Biological Studies Of Carboranyl-Porphyrin Bioconjugates For Treatment Of Brain Tumors, Naga Venkata Satya Dinesh Kumar Bhupathiraju

LSU Doctoral Dissertations

Chapter 1 gives a brief introduction to brain tumors, approaches to deliver drug across the blood brain barrier (BBB), boron neutron capture therapy (BNCT) for brain tumors, application of carboranyl derivatives in attempt to treat brain tumors using BNCT. Chapter 2 involves synthesis, characterization and toxicity studies (In vitro and In vivo) of high boron containing pegylated cobaltabisdicarbollide porphyrin for treatment of brain tumors using BNCT. To improve the selectivity towards brain tumors we attempted conjugate several peptides to this non-toxic pegylated cobaltabiscabollide porphyrin. In vivo studies were conducted in collaboration with Dr. David G. Baker at LSU veterinary Medicine. …


Scanning Probe Investigations Of The Surface Self-Assembly Of Organothiols And Organosilanes Using Nanoscale Lithography, Tian Tian Jan 2013

Scanning Probe Investigations Of The Surface Self-Assembly Of Organothiols And Organosilanes Using Nanoscale Lithography, Tian Tian

LSU Doctoral Dissertations

Particle lithography and scanning probe lithography were applied to study the kinetics and mechanisms of surface self-assembly processes. Organothiols on Au(111) and organosilane on Si(111) were chosen as model systems for investigations at the nanoscale using atomic force microscopy (AFM). Fundamental insight of structure/property interrelationships and understanding the properties of novel materials are critical for developments with molecular devices. Methods using an AFM probe for nanofabrication have been applied successfully to prepare sophisticated molecular architectures with high reproducibility and spatial precision. The established capabilities of AFM-based nanografting were reviewed for inscribing patterns of diverse composition, to generate complicated surface designs …


Cyclic Block Copolypeptoids : Synthesis, Self-Assembly And Macroscopic Properties, Chang-Uk Lee Jan 2013

Cyclic Block Copolypeptoids : Synthesis, Self-Assembly And Macroscopic Properties, Chang-Uk Lee

LSU Doctoral Dissertations

This dissertation presents the first experimental efforts for synthesizing a new class of peptidomimetic polymers, cyclic block copolypeptoids, studying their self-assembly in dilute solution, and examining their macroscopic properties. Cyclic poly(N-methyl-glycine)-b-poly(N-decyl-glycine) (PNMG-b-PNDG) diblock copolymers were synthesized via sequential, N-heterocyclic carbene (NHC)-mediated ring-opening polymerization of NCA monomers with controlled chain length and compositions. Cryo-TEM shows that PNMG105-b-PNDG10 copolymers in methanol (1 mg/mL) form spherical micelles that organize to form cylindrical micelles over time. The formation of cylindrical micelles is attributed to the crystallization of PNDG chains, as revealed by SAED and microDSC analyses. Cyclic PNMG100-b-PNDG10 copolymers form thermo-reversible, free-standing gels at …


Detection Of Microorganisms Using Maldi And Ion Mobility Mass Spectrometry, Juaneka Monet Hayes Jan 2013

Detection Of Microorganisms Using Maldi And Ion Mobility Mass Spectrometry, Juaneka Monet Hayes

LSU Doctoral Dissertations

Matrix-assisted laser ablation desorption ionization MALDI and ion mobility (IM) MALDI mass spectrometry (MS) were used for the detection and identification of microorganisms. MALDI MS is an analytical tool that separates ions by their mass-to-charge ratio (m/z) and is routinely used for bioanalysis because of its sensitivity, selectivity, general applicability, and tolerance to impurities. Ion mobility is a gas phase technique that separates ions based on their charge and collision cross-section. In this research, MALDI-TOF MS and MALDI-IM-TOF MS analysis were conducted in parallel to assess the effectiveness of MALDI-IM-TOF MS for microorganism identification. Whole cell bacteria Escherichia coli strain …


New Strategies For The Synthesis Of Porphyrinoids, Moses Inyanje Ihachi Jan 2013

New Strategies For The Synthesis Of Porphyrinoids, Moses Inyanje Ihachi

LSU Doctoral Dissertations

ABSTRACT Chapter 1 describes the most stable isomer of porphyrin called porphycene. In this chapter photodynamic therapy (PDT) is explained, and the application of porphycenes in PDT is also described. Other biological applications and its uses in catalysis are also summarized here. The general chemical reactions of porphycenes are also explained. Chapter 2 involves the synthesis of pyrroles and bipyrroles. Functionalization of pyrrollic substituents is demonstrated using organometallic coupling reactions like Stille coupling and Grubbs olefin metathesis. The synthesis of divinyl bipyrroles is intended to provide an important precursor to porphycene synthesis via ring closing metathesis using Grubbs catalyst. Chapter …


Phase Behavior Of Silica-Polypeptide Hybrid Particles Immersed In Cholesteric Liquid Crystals, Melissa Elizabeth Collins Jan 2013

Phase Behavior Of Silica-Polypeptide Hybrid Particles Immersed In Cholesteric Liquid Crystals, Melissa Elizabeth Collins

LSU Doctoral Dissertations

Silica-polypeptide hybrid particles are core-shell colloids. Established synthetic methods ensure uniformly sized cores and provide the ability to have magnetic or fluorescent inclusions. The polypeptide shell is highly functional in its ability to respond to stimuli through changes in shape and formation of ordered phases above certain concentrations or temperatures. This research explores the interactions of hybrid particles mixed with polypeptides dispersed in solution. Depletion theory, which considers mainly entropic interactions between particles, can be used to explain the phase behavior of colloids. Due to the chemical similarities between the polypeptides attached to the surface and those free in solution, …


Synthetic Efforts Toward The Eastern Hemisphere Of Theonellamide C, Douglas D. Wong Jan 2013

Synthetic Efforts Toward The Eastern Hemisphere Of Theonellamide C, Douglas D. Wong

LSU Doctoral Dissertations

The theonellamides (TNMs) A-F are bicyclic dodecapeptides isolated from marine sponges of the genus Theonella and were shown to display potent antifungal activity. Despite considerable synthetic effort to produce TNM F by the Shioiri group in the early 1990s, a total synthesis of a TNM has yet to be reported. This dissertation describes our efforts toward some of the required amino acid residues of TNM C and the eastern hemisphere. The production of erythro-β-hydroxyasparagine (eHyAsn) followed the synthesis of threo-β-HyAsn by Boger and co-workers, utilizing a key Sharpless aminohydroxylation reaction. The eHyAsn building block, Boc-eHyAsn(OTBS)-OH, was coupled with HCl.Phe.OMe using …


Fluorescent Materials For Chemical Sensing, Brian Gerard Imsick Jan 2013

Fluorescent Materials For Chemical Sensing, Brian Gerard Imsick

LSU Doctoral Dissertations

Materials incorporating fluorescent π-electron conjugated molecular species for sensing and imaging are advantageous over other detection or identification methods such as colorimetric reporters. Fluorescent materials offer easy recognition of binding events due to the highly sensitive nature of fluorescence techniques down to the single molecule level. The properties of fluorescent molecules allow for rapid attenuation of observable readout due to the facile transport of excited state energy via both inter- and intramolecular pathways. This dissertation primarily focused on the development and study of a general platform for ratiometric fluorescent chemosensing using surface-immobilized oligomers, as well as in depth explorations of …


Synthesis And Cellular Investigations Of The 131-Lysyl Derivative Of Chlorin E6, Stewart Wynn Humble Apr 2012

Synthesis And Cellular Investigations Of The 131-Lysyl Derivative Of Chlorin E6, Stewart Wynn Humble

Honors Capstones

No abstract provided.


Synthesis And Characterization Of Red And Near-Infrared Bodipy-Based Fluorophores For Various Biological Applications, Timsy Kaur Uppal Jan 2012

Synthesis And Characterization Of Red And Near-Infrared Bodipy-Based Fluorophores For Various Biological Applications, Timsy Kaur Uppal

LSU Doctoral Dissertations

ABSTRACT 4,4-Difluoro-3a,4a-diaza-s-indacene, better known as BODIPY® dyes, have attracted considerable attention due to their intriguing physicochemical and spectral properties, including high absorption coefficient, fluorescence quantum yield and good photochemical stability. Despite the recent progress achieved in this field, the synthesis of BODIPY derivatives that absorb and emit in the red- and NIR-region of the electromagnetic spectrum and their application to biomolecular targets, represents a long-standing challenge in BODIPY chemistry. This research work is therefore focused on the synthesis and characterization of red and NIR-emissive BODIPY-based fluorophores for various bioanalytical and biomedical applications. Chapter 1 of this dissertation represents a concise …


Syntheses And Characterization Of Water-Soluble Phythalocyanines For Diagnosis And Treatment Of Cancer, Benson Getenga Ongarora Jan 2012

Syntheses And Characterization Of Water-Soluble Phythalocyanines For Diagnosis And Treatment Of Cancer, Benson Getenga Ongarora

LSU Doctoral Dissertations

Ongarora, Benson Getenga, B.S., Moi University, 2005 Doctor of Philosophy, Fall Commencement, 2012 Major: Chemistry Syntheses and Characterization of Water-Soluble Phthalocyanines for Diagnosis and Treatment of Cancer Dissertation directed by Professor M.Graҫa H. Vicente Pages in dissertation, xi. Words in abstract, 251. ABSTRACT Chapter 1 describes the general properties of phthalocyanines, synthesis of metallo-phthalocyanines, their photophysical features and their uses. The concepts of PDT and targeted therapeutics are also introduced. Chapter 2 describes the syntheses, characterization, photophysical studies and biological evaluation of cationic phthalocyanines. The trimethylaminophenoxy substituted phthalocyanines were synthesized through statistical condensation method, which gave a statistical mixture of …


On The Synthesis, Characterization, And Magnetization Of Ln-M-X (Ln = Lanthanide; M = Ti-Cr, Cu, Mo, Pd; X = Al, Ga) Intermetallics, Michael James Kangas Jan 2012

On The Synthesis, Characterization, And Magnetization Of Ln-M-X (Ln = Lanthanide; M = Ti-Cr, Cu, Mo, Pd; X = Al, Ga) Intermetallics, Michael James Kangas

LSU Doctoral Dissertations

The focus of the research presented herein was to grow single crystals of Ln-M-X (Ln = lanthanide; M = Ti-Cr, Cu, Mo, Pd; X = Al, Ga) intermetallic compounds and to characterize their crystal structures and physical properties. Overall, the flux growth technique facilitated a detailed analysis of previously known structure-types (LnM2Al20 (Ln = La, Ce, Pr, Yb; M = Ti, V, Cr), Ln6M4Al43 (Ln = Gd, Yb; M = Cr, Mo), and Yb2Pd3Ga9), as well as the synthesis and characterization of new compounds (LnCrxGa3 (Ln = Ho, Er; x ~ 0.13), YbCr2Al20-xFex (x ~ 0.2), Ln(Cu,Al,Ga)13-x, and Ln2PdGa12 (Ln …


Beta-Diketone And Beta-Ketoenamine Based Molecular Squares, Jackson Kiplagat Cherutoi Jan 2012

Beta-Diketone And Beta-Ketoenamine Based Molecular Squares, Jackson Kiplagat Cherutoi

LSU Doctoral Dissertations

Abstract This dissertation focuses on synthesis of β-diketone and β-ketoenamine ligands for molecular polygons. Previous work with the bis(β-diketone) m-pbaH2 showed that it can be converted to a copper molecular square, Cu4(m-pba)4, but its use in host-guest reactions was limited by its low solubility in most organic solvents. Accordingly, in the present work, the m-pbhxH2 ligand, with pentyl chains replacing the methyl groups in the β-diketone moieties of m-pbaH2, was successfully prepared beginning with 6-dodecyne. This ligand reacts with Cu2+ to make the molecular square Cu4(m-pbhx)4, which is soluble in a wider range of solvents. Host-guest reactions of Cu4(m-pbhx)4 with …


Ionic Materials For Applications In Sensing And Optoelectronics, Sergio L. De Rooy Jan 2012

Ionic Materials For Applications In Sensing And Optoelectronics, Sergio L. De Rooy

LSU Doctoral Dissertations

Organic salts consist of bulky anions and/or cations whose properties can be tailored for specific purposes. Ionic liquids (ILs) are (semi)organic salts with melting points below 100 ºC. They typically exhibit neglible vapor pressures, high thermal stability, wide liquidus range, and tunable solubility. Moreover specific functions can be built into their respective ions. The first part of the dissertation involves discussions of chiral ionic liquids with additional protic, magnetic, and magneto-luminescent properties, respectively. In addition to their enantioselective sensing capabilities, the ILs may find use in chiral separations and catalysis. The second part of the dissertation involves discussions of fluorescent …


Design, Synthesis, Characterization, And Application Of Peptides As Different Medical Treatment, Krystal Renee Fontenot Jan 2012

Design, Synthesis, Characterization, And Application Of Peptides As Different Medical Treatment, Krystal Renee Fontenot

LSU Doctoral Dissertations

A peptide is defined, as a molecule that contains less than fifty amino acids; anything larger is a protein. Peptides are important molecules because they have diverse uses. Peptides were utilized in two ways: 1) Peptide bioconjugates containing a fluorescent porphyrin or phthalocyanine macrocycle were designed and investigated, with or without a PEG moiety for selective targeting of the epidermal growth factor receptor (EGFR). 2) Amyloid aggregating mitigating peptides (AAMPs) was synthesized and investigated containing polar amino acids, MiniPEGs, and/or ααAAs that have the ability to inhibit and disrupt Amyloid Beta (Aβ). The peptide bioconjugates containing a porphyrin or phthalocyanine …


Kinetic Studies On Lactonization Of Quinone Propionic Acid Derivatives For The Development Of Redox Responsive Liposomes, K. L. Iresha Sampathi Perera Jan 2012

Kinetic Studies On Lactonization Of Quinone Propionic Acid Derivatives For The Development Of Redox Responsive Liposomes, K. L. Iresha Sampathi Perera

LSU Master's Theses

ABSTRACT Stimuli-responsive liposome systems that utilize endogenous triggers of tumor microenvironment have generated great attention in recent drug delivery research. Among such formulations, redox-responsive liposomes seem highly promising for cancer treatment due to their potential to release high drug concentrations upon reduction (by reductase enzymes). The research described in this thesis involved the evaluation of kinetics of trimethyl-lock quinone propionic acid reduction and lactonization, which accounts for payload release from trimethyl-lock quinone propionic acid-decorated liposomes. To achieve the ultimate goal of this research, several trimethyl-lock quinone propionic acid-based amide compounds were synthesized and characterized. Kinetic studies were carried out with …


Synthesis Of Fluorescent Poly(Styrene Sulfonate), Wayne Alfred Huberty Jan 2012

Synthesis Of Fluorescent Poly(Styrene Sulfonate), Wayne Alfred Huberty

LSU Master's Theses

In 1978, Lee found an increase and then a large decrease in the diffusion coefficient of poly(lysine) as the concentration of salt is decreased (Lin, S. C.; Lee, W. I.; Schurr, J. M. Biopolymers 1978, 17, (4), 1041-1064). Since the “slow mode” discovery, many have studied it without finding a fully satisfactory answer. Additional dynamic light scattering (DLS) measurements have been the main experimental technique used for reinvestigating the slow mode decay. Although DLS is a powerful characterization tool, it depends on thermodynamic interactions. As complicated as they can be, thermodynamic interactions are much worse for polyelectrolytes because of the …


Novel Nonresonant And Resonant Mechanisms Leading To The Breakdown Of The Franck-Condon Approximation In Photoionization, David Adam Hardy Jan 2012

Novel Nonresonant And Resonant Mechanisms Leading To The Breakdown Of The Franck-Condon Approximation In Photoionization, David Adam Hardy

LSU Doctoral Dissertations

This thesis attempts to answer the question of how electrons interact with a molecular framework prior to and during emission through photoionization. These studies interrogate several behaviors of allowed and forbidden photoelectron transitions such as shape resonances, non-resonant intrachannel vibronic coupling as a result of Cooper minima, and chemically-induced nonresonant coupling, all of which provide new insights into correlations between the electronic and molecular degrees of freedom. Research presented in this thesis utilizes high-resolution photoelectron spectroscopy, and undulator-based synchrotron radiation at the Advanced Light Source, a synchrotron radiation source in Berkeley, California. Data are collected from near threshold to several …


Studies On A Dirhodium Tetraphosphine Hydroformylation Catalyst, Darina Polakova Jan 2012

Studies On A Dirhodium Tetraphosphine Hydroformylation Catalyst, Darina Polakova

LSU Doctoral Dissertations

The dirhodium tetraphosphine catalyst [Rh2(nbd)2(rac-et,ph-P4)](BF4)2 was investigated in acetone and water/acetone in order to explain better hydroformylation results in the latter solvent. In-situ NMR spectroscopy showed slower degradation in water/acetone. Less tendency to form penta/hexacarbonyl complexes in water/acetone was shown by 31P{1H} NMR and FT-IR. A pH decrease and hydroformylation studies in presence of a base indicated formation of a monocationic monohydride species. A new reaction mechanism was suggested that takes into account the observed differences from the acetone solvent system. The presence of water enabled production of hydride species when the dirhodium catalyst was exposed to CO gas. We …


Single-Molecule Detection Of Molecular Beacons Generated From Ldr On Thermoplastic Microfluidic Device For Bioanalysis, Zhiyong Peng Jan 2012

Single-Molecule Detection Of Molecular Beacons Generated From Ldr On Thermoplastic Microfluidic Device For Bioanalysis, Zhiyong Peng

LSU Doctoral Dissertations

Current clinical techniques for nucleic acid detection and analysis often involve PCR, lacking adequate specificity or sensitivity to meet the stringent requirements in certain applications. This research aims to develop an innovative molecular assay and the associated hardware to rapidly signal the presence of certain targets using reporter sequence found in their genome without requiring PCR. This assay coupled the sensitivity of single-pair fluorescence resonance energy transfer (spFRET) with the specificity of ligase detection reaction (LDR) to provide near real-time readout of target biomarkers. Heightened concerns on potential bioterrorism threats, such as rapid dissemination of pathogenic bacteria or viruses into …


Chemical And Biological Evaluation Of Antibiotic-Based Ionic Liquids And Gumbos Against Pathogenic Bacteria, Marsha Rae Cole Jan 2012

Chemical And Biological Evaluation Of Antibiotic-Based Ionic Liquids And Gumbos Against Pathogenic Bacteria, Marsha Rae Cole

LSU Doctoral Dissertations

The research presented in this dissertation explores a novel pragmatic therapeutic approach for control, prevention, and treatment of infectious disease using Active-Pharmaceutical Ingredient-based Ionic Liquids (API-ILs) and Groups of Uniform Materials Based on Organic Salts (GUMBOS). Accordingly, several antiseptic- and antibiotic-based API-ILs and GUMBOS were synthesized and characterized using a combination of analytical and microbiological techniques. Overall, this research presents an advanced alternative to combination antibiotic therapy by using a novel group of ionic antimicrobial materials that have controlled pharmacokinetics, improved bioavailabilities, reduced toxicities, multi-modal properties, and potent antimicrobial spectrum of activity as a viable alternative to combating bacterial infections. …


Geometrical And Electronic Structure Of Metal Oxide Nanoparticles On Silica And Alumina, Udaya Indike Rodrigo Jan 2012

Geometrical And Electronic Structure Of Metal Oxide Nanoparticles On Silica And Alumina, Udaya Indike Rodrigo

LSU Doctoral Dissertations

Recent studies demonstrated nanometer-scale combustion-generated nanoparticles cause demonstrable health effects. It is essential to understand the chemical characteristics of these nanoparticles. Since combustion-generated nanoparticles arise in complex mixtures, we employed a dendrimeric method to generate simpler, more reproducible nanoparticles, which were tethered to fumed silica and alumina to provide surrogates for fly ash. We collected XANES and EXAFS data, which are useful for characterizing disordered mixtures where the metal is a minor component. The effect of particle size on structural properties was studied with copper oxide nanoparticles on fumed silica. XANES data demonstrated copper atoms in the nanoparticles are present …


Fabrication, Analysis, Application, And Characterization Of Core-Containing Microparticles And Hydrophilic Microfluidic Devices Produced Via The Primary- And In Situ Tertiary-Amine Catalyzed Michael Addition Of Multifunctional Thiols To Multifunctional Acrylates, Christopher O. Bounds Jan 2012

Fabrication, Analysis, Application, And Characterization Of Core-Containing Microparticles And Hydrophilic Microfluidic Devices Produced Via The Primary- And In Situ Tertiary-Amine Catalyzed Michael Addition Of Multifunctional Thiols To Multifunctional Acrylates, Christopher O. Bounds

LSU Doctoral Dissertations

The objective of this research was to investigate amine-catalyzed thiol-acrylate chemistry for various novel applications that could fully utilize the untapped potential of this useful and robust chemistry. The use of this chemistry in each application solved a problem, improved on a disadvantage of current technologies, and decreased the level of complexity in association with required time, cost, and/or preparation conditions. The first novel application conceived, applied, and analyzed was in the field of microencapsulation. A novel approach for the preparation of microparticles via a dispersion polymerization using the primary amine-catalyzed addition of a trithiol to a triacrylate was realized …


Synthesis, Cellular Studies, And Computational Analysis Of Porphyrin And Bodipy Conjugates With Affinity For Epidermal Growth Factor Receptor, Alecia Michelle Mccall Jan 2012

Synthesis, Cellular Studies, And Computational Analysis Of Porphyrin And Bodipy Conjugates With Affinity For Epidermal Growth Factor Receptor, Alecia Michelle Mccall

LSU Doctoral Dissertations

Chapter 1 is a description of the basic fundamental concepts of porphyrins and BODIPYs, (including synthetic methodologies), a general mechanism of the processes of EGFR, and computational concepts that are elaborated upon in future chapters. Chapter 2 is a discussion solely on the porphyrins that were synthesized to be used as fluorophores for EGFR-targeted conjugates, both peptidic and non-peptidic. The porphyrins were primarily synthesized via the Lindsey method as well as by O-alkylation of tetrahydroxy porphyrins. Synthesis of PEG linkages are discussed as well through three methodologies. Chapter 3 is a presentation of the synthesis, characterization, cellular studies, and computational …


Investigations Into The Role Of Natural Organic Matter As An Interface Between Aquatic Organisms And Environmental Pollutants, Caroline Lillian Schneider Jan 2012

Investigations Into The Role Of Natural Organic Matter As An Interface Between Aquatic Organisms And Environmental Pollutants, Caroline Lillian Schneider

LSU Doctoral Dissertations

The impact of the continuous pollution of freshwater environments by multiple pollutants has not been well-studied. The goal of this research was to evaluate the toxicity of several modern pollutants in a model environment. The prokaryotic, unicellular blue-green algae Synechocystis WT6803 and the eukaryotic, multicellular Utterbackia imbecillis mussel larvae were studied along with Suwannee River natural organic matter (NOM). The toxicity response of the blue-green algae Synechocystis sp. was measured through changes in growth rates. The inorganic pollutant silver nanoparticles (0.044 μM) were toxic. Gold nanoparticles did not affect the growth rate. The addition of 15 mg/L NOM partially inhibited …


Chemical Crystallography At The Interface Of Physics, Chemistry, And In Engineering: Structure Determination Of Highly Correlated Extended Solids, Main Group Compounds, Coordination Complexes, And Bioceramics, Gregory Todd Mccandless Jan 2012

Chemical Crystallography At The Interface Of Physics, Chemistry, And In Engineering: Structure Determination Of Highly Correlated Extended Solids, Main Group Compounds, Coordination Complexes, And Bioceramics, Gregory Todd Mccandless

LSU Doctoral Dissertations

Multi-disciplinary research is essential to address the major challenges in science, engineering, and medicine. For these three areas, crystallography has played and continues to play a huge role by providing researchers with the means to determine the structure of a compound and relate these to its properties. This dissertation is highly interdisciplinary, focusing on structure determination of complex systems and materials with tailored applications. This work includes the characterization by single crystal and powder X-ray diffraction of intermetallic extended solids, layered metal oxides, inorganic complexes, discrete organic molecules, and bioceramics. These projects range from modeling translational disorder with pseudo-hexagonal symmetry …


Design And Analysis Of Cloaked Fluorophores For Rapid Detection And Visualization Of Cancer Cells Containing Nad(P)H:Quinone Oxidoreductase-1, William Silvers Jan 2012

Design And Analysis Of Cloaked Fluorophores For Rapid Detection And Visualization Of Cancer Cells Containing Nad(P)H:Quinone Oxidoreductase-1, William Silvers

LSU Doctoral Dissertations

The development of fluorogenic substrates for real-time tumor cell detection has led to a vastly expanding field for personal oncology. Fluorophores have been studied as appendages to larger scaffolds leading to accumulation of these dyes in tumor cells or their surrounding environment, taking advantage of tumor anatomy. A new class of fluorophores has been developed in which the dye is an active participant in the mechanism of cancer cell detection. These dyes have been conjugated such that their fluorescence has been eliminated or altered and will undergo a change to reveal their fluorescent signal upon activation by a mechanism that …


Studies Of A Dirhodium Tetraphosphine Catalyst For Hydroformylation And Aldehyde-Water Shift Catalysis, Aaron Rider Barnum Jan 2012

Studies Of A Dirhodium Tetraphosphine Catalyst For Hydroformylation And Aldehyde-Water Shift Catalysis, Aaron Rider Barnum

LSU Doctoral Dissertations

Research into the dirhodium tetraphosphine catalyst precursor [rac-Rh2(nbd)2(et,ph-P4)](BF4)2 shows it is capable of forming a highly active and regioselective hydroformylation catalyst in situ when using an acetone or acetone/water solvent. Hydroformylation experiments (using 1-hexene), FT-IR studies, and acid-base studies were performed to better understand the various complexes of the dirhodium catalyst cycle. These studies lead to the newly proposed catalyst mechanism when performed in an acetone/water solution, using the monocationic [rac-Rh2(H)(µ-CO)2(CO) (et,ph-P4)]+ as the proposed active catalyst complex for hydroformylation. For the conversion of 1-hexene to heptanal, it is capable of performing an initial rate of 30 turnovers per min, …