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10th Annual Senior Research Symposium Of The Department Of Biological Sciences, Chemistry And Biochemistry, Messiah College

School of Science, Engineering & Health (SEH) Symposium

No abstract provided.

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 …}

On-Metal Synthesis Of Some Rhenium Complexes, Chad L. Phillips

Mahurin Honors College Capstone Experience/Thesis Projects

In 1977, Shirakawa and coworkers discovered the first conductive polymers. Their conductive polymers have been extensively studied. Though some of these first conductive polymers such as polyactelyne seemed to be a promising organic conductor, the commercial applications of these polymers were severely limited due the polymer’s highly air-sensitive nature. Thus, the current focus has shifted towards the development of heterocyclic aromatic polymers which are air-stable and have a low band gap. Expanding of the work of Snyder and Selegue, the focus of my research has been the incorporation of rhenium metal into an organic compound in an on-metal fashion. Several …

Hexakis(Prop-2-Enamide)Copper(Ii) Bis(Perchlorate) And Hexakis(Prop-2- Enamide)Manganese(Ii) Bis(Perchlorate), Mary Mcnamara, Andrew Kellett, Georgina Rosair, Michael Devereux, Malachy Mccann

Articles

The structures of [Cu(AA)6](ClO4)2, (I), and [Mn(AA)6](ClO4)2, (II) (AA is acrylamide, also known as prop-2-enamide; C3H5NO), display both intra- and intermolecular N-H...O hydrogen bonding. A three-dimensional network is propagated via the perchlorate counter-ions. There are two crystallographically independent molecules in the copper complex, with the most significant difference between them being the conformation of one symmetry-related pair of AA ligands which are in the unusual syn conformation. The copper complex exhibits syn/anti disorder of the =CH2 group in one pair of symmetry-related AA ligands. The CuII and MnII centres are both situated on centres of inversion. The copper complex cation …

Chemistry–Climate Model Simulations Of Twenty-First Century Stratospheric Climate And Circulation Changes, Neal Butchart, I. Cionni, V. Eyring, T. G. Shepherd, D. W. Waugh, H. Akiyoshi, J. Austin, C. Brühl, M. P. Chipperfield, Eugene C. Cordero, M. Dameris, R. Deckert, S. Dhomse, S. M. Frith, R. R. Garcia, A. Gettelman, M. A. Giorgetta, D. E. Kinnison, F. Li, E. Mancini, S. Pawson, G. Pitari, D. A. Plummer, E. Rozanov, F. Sassi, J. F. Scinocca, K. Shibata, B. Steil, W. Tian

Faculty Publications, Meteorology and Climate Science

The response of stratospheric climate and circulation to increasing amounts of greenhouse gases (GHGs) and ozone recovery in the twenty-first century is analyzed in simulations of 11 chemistry–climate models using near-identical forcings and experimental setup. In addition to an overall global cooling of the stratosphere in the simulations (0.59 ± 0.07 K decade⁻¹ at 10 hPa), ozone recovery causes a warming of the Southern Hemisphere polar lower stratosphere in summer with enhanced cooling above. The rate of warming correlates with the rate of ozone recovery projected by the models and, on average, changes from 0.8 to 0.48 K decade …

Chemistry–Climate Model Simulations Of Twenty-First Century Stratospheric Climate And Circulation Changes, Neal Butchart, I. Cionni, V. Eyring, T. G. Shepherd, D. W. Waugh, H. Akiyoshi, J. Austin, C. Brühl, M. P. Chipperfield, Eugene C. Cordero, M. Dameris, R. Deckert, S. Dhomse, S. M. Frith, R. R. Garcia, A. Gettelman, M. A. Giorgetta, D. E. Kinnison, F. Li, E. Mancini, S. Pawson, G. Pitari, D. A. Plummer, E. Rozanov, F. Sassi, J. F. Scinocca, K. Shibata, B. Steil, W. Tian

Eugene C. Cordero

The response of stratospheric climate and circulation to increasing amounts of greenhouse gases (GHGs) and ozone recovery in the twenty-first century is analyzed in simulations of 11 chemistry–climate models using near-identical forcings and experimental setup. In addition to an overall global cooling of the stratosphere in the simulations (0.59 ± 0.07 K decade⁻¹ at 10 hPa), ozone recovery causes a warming of the Southern Hemisphere polar lower stratosphere in summer with enhanced cooling above. The rate of warming correlates with the rate of ozone recovery projected by the models and, on average, changes from 0.8 to 0.48 K decade …

Guest Induced Transformations Of Assembled Pyridyl Bis-Urea Macrocycles, Kinkini Roy, Chun Wang, Mark D. Smith, Mahender B. Dewal, Arief C. Wibowo, Julius C. Brown, Shugo Ma, Linda S. Shimizu

Faculty Publications

Pyridine macrocycles with no cavities assembled into close packed columns yet absorbed guests including hydrogen, carbon dioxide, and iodine.

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 …

Cytotoxicity Of Cu(Ii) And Zn(Ii) 2,2′-Bipyridyl Complexes: Dependence Of Ic_50 On Recovery Time, Yi Shi, Bonnie B. Toms, Namrata Dixit, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

We measure the cytotoxicity of three metal complexes containing the 2,2′-bypyridine ligand, Cu(bpy)(NCS)2, 1, [Cu(bpy)2(H2O)](PF6)2, 2, and Zn(bpy)2(NCS)2, 3, toward neuroblastoma cells (SKN- SH) and ovarian cancer cells (OVCAR-3) using two different cell assays. The cells were exposed to various concentrations of the compounds for 1 h and the percent inhibition of cell growth, I, measured for various times after exposure, i.e., as a function of the recovery time t. After developing the theory showing the relationship between I and t, the cytotoxicity data were analyzed to reveal that the two copper complexes, 1 and 2, cause the cells to …

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 …

Open Notebook Science Challenge Solubilities Of Organic Compounds In Organic Solvents, Andrew Lang, Jean-Claude Bradley, Cameron Neylon, Rajarshi Guha, Antony J. Williams, Bill Hooker, Brent Friesen

College of Science and Engineering Faculty Research and Scholarship

The Open Notebook Science Solubility Challenge Solubility is an important consideration for many chemistry applications. Synthetic chemists usually use a solvent to perform reactions and knowledge of the solubility of the starting materials or products can be very useful to pick an appropriate solvent. Analytical chemists can use solubility to design separation techniques and factor in dynamic range considerations. Physical chemists can create and evaluate their models of how molecules interact in the solubilization and precipitation processes. Solubility data can be obtained from a variety of online and offline sources. As with all chemical data, it can be a challenge …

Tetraaquabis(3-Fluoropyridine-4-Carboxylato-Κn)Zinc(Ii) Dihydrate, Jonetha Fleming, Jennifer Kelley, Leroy Peterson Jr., Mark D. Smith, Hans-Conrad Zur Loye

Faculty Publications

In the title compound, [Zn(C₆H₃FNO₂)₂(H₂O)₄]·2H₂O, the Zn^II atom is octahedrally coordinated in a ZnO₄N₂ environment by two 3-fluoropyridine-4-carboxylate (3-fpy4-cbx) ligands and four water molecules. The [Zn(3-fpy4-cbx)₂(H₂O)₄] molecules form a three-dimensional network through strong O-HO and weak O-HF hydrogen bonds between 3-fpy4-cbx and water molecules. The crystal used for data collection was a twin, with the twin law corresponding to a 180° rotation about the real-space [001] axis. The major twin fraction refined to 0.795 (1).

A Framework For Automated Enrichment Of Functionally Significant Inverted Repeats In Whole Genomes, Cyriac Kandoth, Fikret ErçAl, Ronald L. Frank

Computer Science Faculty Research & Creative Works

Background: RNA transcripts from genomic sequences showing dyad symmetry typically adopt hairpin-like, cloverleaf, or similar structures that act as recognition sites for proteins. Such structures often are the precursors of non-coding RNA (ncRNA) sequences like microRNA (miRNA) and small-interfering RNA (siRNA) that have recently garnered more functional significance than in the past. Genomic DNA contains hundreds of thousands of such inverted repeats (IRs) with varying degrees of symmetry. But by collecting statistically significant information from a known set of ncRNA, we can sort these IRs into those that are likely to be functional.

Results: A novel method was developed to …

Poly[[(Μ-2,2'-Bipyrimidine-Κ4N1,N1':N3,N3')(Μ-Sulfato-Κ2O:O')Zinc(Ii)] Monohydrate], Aaron Oxendine, Jennifer Kelley, Leroy Peterson Jr., Mark D. Smith, Hans-Conrad Zur Loye

Faculty Publications

In the title compound, {[Zn(SO₄)(C₈H₆N₄)]·H₂O}_n, the Zn^II atom is in a distorted octahedral environment. The Zn^II atoms are bridged by both 2,2'-bipyrimidine and sulfate ligands, thus forming a three-dimensional polymeric metal-organic solid that contains uncoordinated water molecules in the interstitial space. O-HO hydrogen bonding consolidates the crystal structure.

The Synthesis Of Azaperylene-9,10-Dicarboximides, Brett Vanveller, Kojl Miki, Timorthy M. Swager

Brett VanVeller

The efficient synthesis of a hydrophilic monomer bearing a three-dimensional noncompliant array of hydroxyl groups is described that prevents water-driven excimer features of hydrophobic poly(p-phenylene ethynylene) backbones. Sensitivity of the polymer to 3-nitrotyrosine is also discussesd.

A Dielectric Affinity Microbiosensor, Xian Huang, Siqi Li, Jerome S. Schultz, Qian Wang, Qiao Lin

Faculty Publications

We present an affinity biosensing approach that exploits changes in dielectric properties of a polymer due to its specific, reversible binding with an analyte. The approach is demonstrated using a microsensor comprising a pair of thin-film capacitive electrodes sandwiching a solution of poly(acrylamide-ran-3-acrylamidophenylboronic acid), a synthetic polymer with specific affinity to glucose. Binding with glucose induces changes in the permittivity of the polymer, which can be measured capacitively for specific glucose detection, as confirmed by experimental results at physiologically relevant concentrations. The dielectric affinity biosensing approach holds the potential for practical applications such as long-term continuous glucose monitoring.

Quantum Trajectory Dynamics In Imaginary Time With The Momentum-Dependent Quantum Potential, Sophya Garashchuk

Faculty Publications

The quantum trajectory dynamics is extended to the wave function evolution in imaginary time. For a nodeless wave function a simple exponential form leads to the classical-like equations of motion of trajectories, representing the wave function, in the presence of the momentum-dependent quantum potential in addition to the external potential. For a Gaussian wave function this quantum potential is a time-dependent constant, generating zero quantum force yet contributing to the total energy. For anharmonic potentials the momentum-dependent quantum potential is cheaply estimated from the global Least-squares Fit to the trajectory momenta in the Taylor basis. Wave functions with nodes are …

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 …

Shorter Still: Compressing C-C Single Bonds, Gerarso Martinez-Guajardo, Kelling J. Donald, Bernard K. Wittmaack, Miguel Angel Vazquez, Gabriel Merino

Chemistry Faculty Publications

How short can a C-C single bond get? The bonding in a set of molecules that are related structurally to previously synthesized or theoretically examined systems with short C-C bonds is investigated. According to calculations, a single C-C bond could be compressed to 1.313 A! To the best of our knowledge, this is the shortest single C-C bond reported to date. This shortening is a consequence of a change in the C-C-C bond angle, θ, to minimize strain in the cages and an effort to offset the tension in the surrounding bridges.

Chemistry Of Hydrogen Oxide Radicals (Hox) In The Arctic Troposphere In Spring, J Mao, D J. Jacob, M J. Evans, J R. Olson, X Ren, W H. Brune, T M. St. Clair, J D. Crounse, K M. Spencer, M R. Beaver, P O. Wennberg, M J. Cubison, J L. Jimenez, A Fried, P Weibring, J G. Walega, S R. Hall, A J. Weinheimer, R C. Cohen, G Chen, J H. Crawford, C Mcnaughton, A D. Clarke, L Jaegle, Jenny A. Fisher, R M. Yantosca, P Le Sager, C C. Carouge

Faculty of Science - Papers (Archive)

We use observations from the April 2008 NASA ARCTAS aircraft campaign to the North American Arctic, interpreted with a global 3-D chemical transport model (GEOS-Chem), to better understand the sources and cycling of hydrogen oxide radicals (HO_x≡H+OH+peroxy radicals) and their reservoirs (HO_y≡HO_x+peroxides) in the springtime Arctic atmosphere. We find that a standard gas-phase chemical mechanism overestimates the observed HO₂ and H₂O₂ concentrations. Computation of HO_x and HO_y gas-phase chemical budgets on the basis of the aircraft observations also indicates a large missing sink for both. We hypothesize that …

Protein Chemistry Of Amyloid Fibrils And Chaperones: Implications For Amyloid Formation And Disease, Justin J. Yerbury, Janet R. Kumita

Faculty of Science - Papers (Archive)

Understanding the mechanisms by which amyloid fibrils are formed, both in vivo and in vitro, is vital for developing methods to treat and prevent debilitating deposition diseases such as Alzheimer's disease, Parkinson's disease, type II diabetes and systemic amyloidoses. In recent years, computer modelling and biophysical studies have broadened our understanding of the biochemical mechanisms underpinning protein aggregation. As a result, it is now believed that the ability to form fibrils is an intrinsic property of polypeptide chains and not isolated to disease-related proteins or peptides. Molecular chaperones are a diverse group of functionally related proteins well known for their …

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 …

The Efficacy Of Chemistry Outreach Programs On Middle School Students, Erica M. Dumeyer

Mahurin Honors College Capstone Experience/Thesis Projects

The current project was designed to determine if science outreach programs affect the attitude of the students toward science and increase the science content knowledge of the students participating in the program. Students from middle schools surrounding the Bowling Green area participated in the project. The data set includes a total of 850 students from 7th and 8th grade. Students were given a pre-test (taken several days before the presentation) and a post-test (taken several days after the presentation). The tests contain both subjective, affective as well as objective, content questions. The individual student pre-/post-tests were index numbered to protect …

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

Browse all Theses and Dissertations

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 …