Chemistry Commons^™

Synthesis And Catalytic Applications Of Platinum(Ii) And Palladium(Ii)-Pta And Dapta Complexes, Sitaram Acharya

Dissertations

The cage-like tertiary phosphine, 1,3,5-triaza-7-phosphaadamantane (PTA) has recently received interest because of its water-solubility, air-stability, non-ionic, non-surfactant, and basic nature. These properties can solubilize transition metal complexes in the aqueous phase. A related air-stable derivative, N,N’-diacetyl-1-3-5-triaza-7-phosphaadamantane (DAPTA) has greater water-solubility than PTA, however, its coordination chemistry has not been significantly explored. This study involved the synthesis and characterization of a series of novel air-stable and water-soluble four-coordinated dialkyl, dialkynyl, dihalo, and halo(alkyl) complexes of platinum and palladium bearing PTA and DAPTA ligands. The alkyl complexes of the type MX(R)P2 (M = Pt, Pd; X = Cl, Br, I; R = …

Incorporation Of Quantum Effects For Selected Degrees Of Freedom Into The Trajectory-Based Dynamics Using Spatial Domains, Sophya V. Garashchuk, Mikhail V. Volkov

Faculty Publications

The approach of defining quantum corrections on nuclear dynamics of molecular systems incorporated approximately into selected degrees of freedom, is described. The approach is based on the Madelung-de-Broglie-Bohm formulation of time-dependent quantum mechanics which represents a wavefunction in terms of an ensemble of trajectories. The trajectories follow classical laws of motion except that the quantum potential, dependent on the wavefunction amplitude and its derivatives, is added to the external, classical potential. In this framework the quantum potential, determined approximately for practical reasons, is included only into the “quantum” degrees of freedom describing light particles such as protons, while neglecting with …

Nickel Catalyzed Homoallylation Reactions And Synthesis Of Potent Inhibitors Of Yoph, Mahesh Prasad Paudyal

Dissertations

Amphidinolides are cytotoxic natural products isolated from marine dinoflagellate Amphidinium species. Amphidinolides C, C2 and F are active against cancer cell lines. Homoallylation of aldehydes with isoprene and triethylborane catalyzed by Ni(acac)2 gave hydroxyalkenes in good yield with excellent regio- and stereoselectivity. Cross metathesis of the hydroxyalkenes with methyl acrylate using second-generation Grubbs catalyst and copper(I) iodide afforded α,β-unsaturated esters, which underwent cyclization in the presence of DBU to produce tetrahydrofurans with the correct relative configuration for the C1-C9 fragment of amphidinolides C, C2, and F. Homoallylation of chiral and achiral diene carboxylate esters and dienecarboxamides with various aldehydes were …

A Review On The Visible Light Active Titanium Dioxide Photocatalysts For Environmental Applications, Miguel Pelaez, Nicholas Nolan, Suresh Pillai, Michael Seery, Polycarpos Falaras, Athanassios G. Kontos, Patrick S.M. Dunlop, Jeremy W.J. Hamiltone, J. Anthony Byrne, Kevin O’Shea, Mohammad H. Entezari, Dionysios D. Dionysiou

Articles

Development of visible light active (VLA) titania photocatalysts

Fujishima and Honda (1972) demonstrated the potential of titanium dioxide (TiO 2) semiconductor mate-rials to split water into hydrogen and oxygen in a photo-electrochemical cell. Their work triggered the development of semiconductor photocatalysis for a wide range of environmental and energy applica-tions. One of the most significant scientific and commercial advances to date has been the development of visible light active (VLA) TiO2 photocatalytic materials. In this review, a background on TiO2 struc-ture, properties and electronic properties in photocatalysis is presented. The development of different strategies to modify TiO2 for the utilization …

Immobilized Bis-Indenyl Ligands For Stable And Cost-Effective Metallocene Catalysts Of Hydrogenation And Polymerization Reactions, Thomas Max Simerly

Electronic Theses and Dissertations

Reactions of catalytic hydrogenations and polymerizations are widely used in industry for manufacture of fine chemicals, pharmaceuticals, and plastics. Homogeneous catalysts for the processes that have low stability and their separation is difficult. Therefore, the development of new highly active and stable catalysts for hydrogenations and polymerizations is a necessity. The objective of this research was the development of a strategy for immobilization of heterogeneous metallocene catalysts. First, a methodology of immobilization of bis-indenyl ligands on the surface of mesoporous silica gel was designed. Four bis-indenyl ligands containing functionalized tethers of various lengths with terminal alkene groups were synthesized. All …

Dynamical Reaction Pathways In Eley-Rideal Recombination Of Nitrogen From W(100), Ernesto Quintas-Sánchez, P. Larrégaray, C. Crespos, L. Martin-Gondre, J. Rubayo-Soneira, J. C. Rayez

Chemistry Faculty Research & Creative Works

The scattering of atomic nitrogen over a N-pre-adsorbed W(100) surface is theoretically described in the case of normal incidence off a single adsorbate. Dynamical reaction mechanisms, in particular Eley-Rideal (ER) abstraction, are scrutinized in the 0.1-3.0 eV collision energy range and the influence of temperature on reactivity is considered between 300 and 1500 K. Dynamics simulations suggest that, though non-activated reaction pathways exist, the abstraction process exhibits a significant collision energy threshold (0.5 eV). Such a feature, which has not been reported so far in the literature, is the consequence of a repulsive interaction between the impinging and the pre-adsorbed …

Synthesis, Crystal Structure, And Rearrangements Of Ortho-Cyclophane Cyclotetraveratrylene (Cttv) Tetraketone, Marlon R. Lutz Jr., Matthias Zeller, Samuel R.S. Sarsah, Artur Filipowicz, Hailey Wouters, Daniel Becker

Chemistry: Faculty Publications and Other Works

Oxidation of cyclotetraveratrylene (CTTV) with potassium permanganate in pyridine under reflux gave tetraketone (the [14]ketonand) 3 which exists as a previously unobserved barrel conformation with S4symmetry in the crystal structure, although the more familiar ‘boat’ conformer was shown by semi-empirical AM1 calculations to be 3.03 kcal/mol lower in energy. In addition to CTTV tetraketone 3, an isomeric bis-spirolactone 4 was isolated from the basic oxidation conditions, analogous to the product of trans-annular attack and rearrangement observed with oxidation of cyclotriveratrylene, whereas in acid at elevated temperatures, tetraketone 3 underwent a very efficient rearrangement and decarboxylation to afford the highly symmetric …

Breast Tumour Initiating Cell Fate Is Regulated By Microenvironmental Cues From An Extracellular Matrix, Sharmistha Saha, Pang-Kuo Lo, Xinrui Duan, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells, also known as tumour-initiating cells (TICs), are identified as highly tumorigenic population within tumours and hypothesized to be main regulators in tumour growth, metastasis and relapse. Evidence also suggests that a tumour microenvironment plays a critical role in the development and progression of cancer, by constantly modulating cell–matrix interactions. Scientists have tried to characterize and identify the TIC population but the actual combination of extracellular components in deciphering the fate of TICs has not been explored. The basic unanswered question is the phenotypic stability of this TIC population in a tissue extracellular matrix setting. The in vivo …

Gas Phase Characterization Of Supramolecules Using Cross-Sectional Areas By Fticr And Sustained Off-Resonance Irradiation Collision Induced Dissociation Techniques In A Fourier Transform Ion Cyclotron Resonance Mass Spectrometer, Fan Yang

Theses and Dissertations

In my dissertation, I use a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FTICR-MS) to investigate supramolecules. Cross-sectional areas by Fourier transform ICR (CRAFTI), a novel technique for measurements of collision cross sections by FTICR, is demonstrated for the first time. The CRAFTI method measures the total "dephasing cross section" for removal of the ions from the coherent packet in the FTICR cell, including contributions not only from momentum transfer but also from reactive collisions including those leading to collisional dissociation. Experimental CRAFTI collision cross sections correlate linearly with theoretically computed results and with results obtained using ion mobility measurements. …

Mass Spectroscopic Identification And Quantification Of Protein Carbonyls, Zafer Ugur

Theses and Dissertations

It is well established that free radical mediated oxidative stress plays a critical role in aging and age-related diseases. Among the post-translational protein modifications, carbonylation has attracted a great deal of attention due to its irreversible and irreparable nature. Despite the fact that protein carbonylation is associated with a series of physiological and pathological processes, there are still issues to be clarified such as why certain proteins are more vulnerable to modification, what are the locations of the protein modifications, and how does the nature of the oxidant affect the preferred site of modification. In this study, we will seek …

Multiple Recoding Mechanisms Produce Cyclooxygenase And Cyclooxygenase-Related Proteins From Frameshift-Containing Cox-3/Cox-1b Transcripts In Rat And Human, John Cameron Hunter

Theses and Dissertations

To increase diversity of enzymes and proteins, cells mix and match exonic and intronic regions retained in mature mRNAs by alternative splicing. An estimated 94% of all multi-exon genes express one or more alternatively spliced transcripts generating proteins with similar or modified functions. Cyclooxygenase is a signaling enzyme that catalyzes the rate-limiting step in the synthesis of diverse bioactive lipids termed prostaglandins. Prostaglandins are involved in myriad physiological and pathopysiological processes including vasoregulation, stomach mucosal maintenance, parturition, pain, fever, inflammation, neoplasia and angiogenesis and are inhibited by aspirin-like drugs known as NSAIDs. In 2002 an alternatively spliced, intron-1 retaining variant …

Flow Valve Diagnostics For Label-Free, Quantitative Biomarker Detection: Device Fabrication, Surface Modification, And Testing, Danielle Scarlet Mansfield

Theses and Dissertations

Diseases are often diagnosed by detection of disease-specific biomarkers in fluid samples. However, many state-of-the-art detection methods require a lab with complex machinery, trained operators, and/or lengthy analysis time. In contrast, point-of-care (POC) devices are brought to the patient's location, they are easy to use, and results are obtained almost immediately. Many current POC devices are too difficult to be used without a skilled assistant, and although many are able to detect analytes above a threshold value, they give little or no quantitative information. This work presents the development of polymer-based microfluidic devices capable of sensing and quantifying biomarkers in …

Synthesis And Biological Evaluation Of Various Derivatives Of A Broad-Spectrum Anticancer Nucleoside, Jadd R. Shelton

Theses and Dissertations

Recently the Peterson lab discovered a promising anticancer adenosine derivative-- 2´,3´-bis-O-tert-butyldimethylsilyl-5´-deoxy-5´-[N-(methylcarbamoyl)amino]-N6-(N-phenylcarbamoyl)adenosine. This compound showed selective toxicity against human colon cancer cells in vitro with LC50's = 6--10 µM. It was hypothesized that the lead compound exerted its cytotoxic effects by interacting with a protein kinase. A systematic Structure Activity Relationship (SAR) was undertaken in an attempt to increase the kinase-binding affinity of the lead compound. Many regions of the lead compound were examined: the N6-phenyl urea moiety, the 5´-N-methyl urea group, the 2´,3´-bis-O-TBS groups, the nucleobase, and the ribose sugar. Results of these studies produced some promising new derivatives. In …

Studies Toward Tetrahydrofuran-Containing Natural Products: Total Synthesis Of Amphidinolide C And Oxylipids, Sudeshna Roy

Dissertations

Tetrahydrofurans (thf) and tetrahydropyrans (thp) are important structural motifs found in a broad array of biologically relevant natural products such as polyether antibiotics and acetogenins. Classic methods used for thf- or thp-ring synthesis have their own advantages and disadvantages which tend to be substrate specific. Therefore, development of new and efficient methods is imperative especially to address the issue of diastereoselectivity when attainment of both cis- and trans-2,5-thf (or 2,6-thp) is highly desirable. Herein, a strategy of cross-metathesis and Pd(0)-catalyzed cyclization, useful for obtaining both cis- and trans-2,5-disubstituted thf (or 2,6-disubstituted thp), will be discussed along with its application in …

Spectroscopic Study Of Host-Guest Inclusion Complexes, Jenessa Lucas, Jennifer Holt

Symposium on Research and Creative Expression (SORCE)

A host-guest complex is formed by a host molecule encapsulating a guest molecule within it. The host materials in this study are basket-shaped structures, known as cyclodextrins, which can easily incorporate a variety of guests, such as drug molecules. These inclusion complexes made with cyclodextrins and drugs can be developed to have different release rates within the body. The cyclodextrin can be used to protect the drug until it reaches its destination within the body. This study focuses on Brooker’s merocyanine (BM) as the guest molecule, since it has a similar structure to stilbene-related drugs. UV/Vis and fluorometer spectroscopic studies …

Expanding And Testing A Computational Method For Predicting The Ground State Reduction Potentials Of Organic Molecules On The Basis Of Empirical Correlation To Experiment, Eugene J. Lynch, Amy L. Speelman, Bryce A. Curry, Charles S. Murillo, Jason G. Gillmore

Faculty Publications

A method for predicting the ground state reduction potentials of organic molecules on the basis of the correlation of computed energy differences between the starting S-0 and one-electron-reduced D-0 species with experimental reduction potentials in acetonitrile has been expanded to cover 3.5 V of potential range and 74 compounds across 6 broad families of molecules. Utilizing the conductor-like polarizable continuum model of implicit solvent allows a global correlation that is computationally efficient and has improved accuracy, with r(2) > 0.98 in all cases and root mean square deviation errors of(mean absolute deviationsmV) for either B3LYP/6-311+G(d,p) or B3LYP//6-31G(d) with an appropriate choice …

Water Quality In Restored Wetlands And The Valparaiso Chain Of Lakes Watershed, Diandra Obermeyer, John Stewart

Symposium on Research and Creative Expression (SORCE)

Over the past decade, The Great Marsh has been undergoing a restoration process. In conjunction with the National Park Service and LAC, Valparaiso has taken an active role in monitoring the restoration effort. Previously, 18 different sites entering, within, and exiting The Great Marsh had been established. Over the past few years, 16 water quality parameters were monitored at those sites. These parameters included total and reactive phosphorus testing, temperature, chloride, nitrate, and dissolved oxygen levels. Previously the data has shown a decrease in all values from entering to exiting the marsh. This decrease indicates that the wetland has been …

The Search For An Epoxide Precursor In Trimethylenemethane (Tmm) Cycloaddition Reactions, Christopher Miko

Symposium on Research and Creative Expression (SORCE)

Trimethylenemethane (TMM) cycloaddition is a Pd(0)-catalyzed process in which new carbon rings are formed, which can be potentially useful in synthetic organic processes. The epoxide starting material (trimethyl(2-oxiranyl-2-propenyl)silane) was created in a three-step process from propargyl alcohol. This molecule was subjected to various reaction conditions in order to test the theoretical assumptions of the reaction mechanism. Efforts to characterize the product(s) are ongoing.

Improving Assessment Strategies In General Chemistry, Samantha Cassell

Symposium on Research and Creative Expression (SORCE)

In an effort to improve assessment strategies in a general chemistry course at Valparaiso University, a new homework submission and evaluation system was implemented. Learning objectives for the course were revised to match new goals. These updated learning objectives guided the creation of homework problem sets on the LearningOnline Network with Computer-Assisted Personalized Approach (LON-CAPA). This free, open-source, distributed learning content management system provides improved homework assessment for students through immediate feedback, personalized questions, and a flexible format. Homework for the first semester general chemistry course was prepared on LON-CAPA and a simple user's guide was also created for LON-CAPA …

Determination Of Flow Rate Using Ultrasonic Sensing For Water Quality Monitoring, Peter Bocek

Symposium on Research and Creative Expression (SORCE)

To monitor the water quality of a stream or river, one must accurately and continuously measure the flow rate. The goal of this project is to build an inexpensive, accurate, and reliable flow meter that will provide continuous flow rate data. Our meter design operates by using an ultrasonic sensor to determine the height of the stream as it passes over a weir. This height can be directly related to the flow rate of the stream. By combining flow data with other water quality measures (e.g., phosphorous concentration), one can quantitatively characterize the health of the stream.

The Fe-Type Nitrile Hydratase From Comamonas Testosteroni Ni1 Does Not Require An Activator Accessory Protein For Expression In Escherichia Coli, Misty L. Kuhn, Salette Martinez, Natalie Gumataotao, Uwe Bornscheuer, Dali Liu, Richard C. Holz

Chemistry Faculty Research and Publications

We report herein the functional expression of an Fe-type nitrile hydratase (NHase) without the co-expression of an activator protein or the Escherichia coli chaperone proteins GroES/EL. Soluble protein was obtained when the α- and β-subunit genes of the Fe-type NHase Comamonas testosteroni Ni1 (CtNHase) were synthesized with optimized E. coli codon usage and co-expressed. As a control, the Fe-type NHase from Rhodococcus equi TG328–2 (ReNHase) was expressed with (ReNHase^+Act) and without (ReNHase^−Act) its activator protein, establishing that expression of a fully functional, metallated ReNHase enzyme requires the …

Synthesis And Characterization Of Sugar Derivatives As Functional Gelators, Michael J. St Martin

LSU New Orleans Theses and Dissertations

Systems formed by the supramolecular assemblages of organic molecules known as organogelators and hydrogelators are currently, and only recently, a subject of great attention and promise. In this context, low molecular weight gelators (LMWGs) are of particular interest because they provide a bottom-up approach to the formation of supramolecular architectures through self-assembly. Gelator molecules do so via the initial formation of a one-dimensional array of individual molecules bound non-covalently through forces such as: hydrogen bonds, electrostatic forces, Van der Waals interactions, and other weak forces such as π-π interactions. These interactions then lead to secondary structure formation through a similar …

Surface Functionalized Water-Dispersible Magnetite Nanoparticles: Preparation, Characterization And The Studies Of Their Bioapplications, Haiou Qu

LSU New Orleans Theses and Dissertations

Iron oxide magnetic nanoparticle synthesis and their surface functionalization hold a crucial position in the design and fabrication of functional materials for a variety of biomedical applications. Non-uniform nanoparticles with poor crystallinity, prepared by conventional methods, have only limited value in biological areas. Large scale synthesis methods that are able to produce high quality, mono-dispersed iron oxide nanoparticles using low cost and environment friendly chemicals are highly desirable. Following synthesis, appropriate surface functionalization is necessary to direct the dispersibility of nanoparticles in aqueous solution in order to provide them with acceptable colloidal stability against the ion strength and many biomolecules …

Theoretical Approaches To The Characterization Of Water, Aqueous Interfaces, And Improved Sampling Of Protein Conformational Changes, Alexis J. Lee

LSU New Orleans Theses and Dissertations

Methods to advance the understanding of water and other aqueous systems are devel- oped. This work falls into three areas: The creation of better interaction potentials for water, improved methods for sampling configurational space, and the applications of these methods to understand systems of interest. Charge transfer has been shown by ab initio methods to be important in the water–water and water–ion interactions. A model for treating charge transfer in liquid water and aqueous systems is presented in this manuscript. The model is called Discrete Charge Transfer (DCT) and is based on the commonly-used TIP4P/2005 model, which represents the charge …

Phoenix Mars Mission Wet Chemistry Laboratory Detection Limit Of Martian Soil Oxidants, Lauren B. Petersen, Richard C. Quinn Dr.

STAR Program Research Presentations

This project utilizes the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) Wet Chemistry Laboratory Testbed (WCL), a payload component of the NASA Phoenix Mars Mission, to analyze Mars soil analogs to find the limits of detection for various compounds of interest- including peroxides, chlorates, sulfates, and other oxidants. When the Phoenix Rover landed in the northern plains of Mars in the summer of 2008, three soil samples were analyzed for soluble components. In this analysis, large amounts of perchlorate were detected. Now, we are relooking at the Phoenix data to see if it shows evidence of other oxidants. The electrochemical techniques …

Quantification And In Vitro Analysis Of Nanolipoproteins (Nlps) Containing Adjuvants, Purna Venkataraman, Craig Blanchette, Nicholas O. Fischer

STAR Program Research Presentations

Nanolipoprotein particles (NLPs) self-assemble into nanoscale structures that can be used as vaccines or drug delivery agents. Due to the nature of the NLPs, a variety of immune stimulating compounds or adjuvants can be readily incorporated into NLPs: a characteristic difficult to engineer into most other nanoscale platforms. In light of this, a method for quantifying the amount adjuvant actually incorporated into NLPs is a question of high importance. Through the use of reverse phase High-Performance Liquid Chromatography (HPLC) and an Evaporative Light Scattering Detector (ELSD), standard curves can be constructed by analyzing mixtures of NLP components of known concentration, …

Cr-Hollandite: Breaking Tradition With Todorokite-Type Manganese Oxides, Stanton Ching, Jonathan P. Franklin, Carley M. Spencer

Chemistry Faculty Publications

The synthesis of a tunneled hollandite-type manganese oxide with interstitial and framework Cr³⁺ is described. This unique material is prepared from a layered buserite precursor under conditions previously believed to only yield todorokite-type manganese oxides with larger tunnels. The influence of Cr³⁺ in promoting the hollandite structure has been investigated by selectively placing the cation either in interstitial or framework sites. The use of framework Cr³⁺ in combination with other interstitial cations generates related hollandite and todorokite derivatives. Catalytic oxidation reactions with benzyl alcohol and carbon monoxide have also been examined.

Covalent Modification That Enhances Protein Properties And Functions And Folds Random Coil Into Alpha-Helix, Deepali Prashar

Chemistry - Dissertations

Understanding the fundamental science of aggregation and surface adsorption of proteins is critical for developing protein-based drugs, understanding aggregation-induced diseases and for preventing biofouling that impacts a wide range of industries. In spite of the advances in sensitive and high-throughput analytical methods, the commercialization of protein drugs has been impeded by poor solubility, inevitable aggregation, and difficulty in purification. The primary aim of this dissertation is to modify proteins covalently to induce folding in random coil sequences, prevent aggregation, surface adsorption and for increasing the thermal stability against aggregation of proteins.

The first chapter describes the chemistry for modifying the …

Synthesis And Characterization Of Graphene Oxide, Jeremy A. Waddell, Arthur Cheng, Bin Chen

STAR Program Research Presentations

Graphene, a single atomic layer of sp² carbon atoms, has gotten a lot of attention from the scientific community because of its excellent mechanical and electronic properties. The mechanical exfoliation methods used to obtain graphene nanosheets are not effective for large scale manufacturing, so scalable synthesis approaches from structurally similar compounds are of great scientific interest. Graphene oxide is one such compound which is synthesized through the oxidation of graphite powder. The oxidation was performed using a modification of the previous experimental procedure. After synthesis, the powder was fabricated into graphene oxide films through vacuum filtration and transfer to …

Photochemical Oxidation Studies Of Porphyrin Ruthenium Complexes, Eric Vanover

Masters Theses & Specialist Projects

In nature, transition metal containing enzymes display many biologically important, attractive and efficient catalytic oxidation reactions. Many transition metal catalysts have been designed to mimic the predominant oxidation catalysts in nature, namely, the cytochrome P450 enzymes. Ruthenium porphyrin complexes have been the center of this research and have successfully been utilized, as catalysts, in major oxidation reactions, such as the hydroxylation of alkanes. The present work focuses on photocatalytic studies of aerobic oxidation reactions with well characterized ruthenium porphyrin complexes.

The photocatalytic studies of aerobic oxidation reactions of hydrocarbons The photocatalytic studies of aerobic oxidation reactions of hydrocarbons catalyzed by …