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Water-Soluble Reversible Addition-Fragmentation Chain Transfer (Raft) Agents And Their Bioconjugation To Dsdna, Dylan F. Finneran

Master's Theses and Capstones

Understanding the properties of bioconjugates and biomaterials has increasingly become the focus of pharmaceutical companies, material scientists, and academia due to their growing list of applications. Bioconjugates have found broad use in therapeutics, drug delivery, tissue engineering, and biosensing. Historically, interest in specific bioconjugates has depended on the cost-availability of the biomacromolecule, making proteins the most well studied, given their relatively low cost and ease of production. However, recent technological advances in plasmid DNA (pDNA) production from E. Coli allow for greater cost-efficiency, changing the landscape of biomaterial research. Employing alkylating agents with known chemo-selectivity to nucleophilic sites on DNA, …

Photocatalysis Using Tio2 Nanoparticles Containing Surface Metal Sites, Benjamin D. Stewart

Master's Theses and Capstones

In recent years, exploration of the functionalization of nanoparticle surfaces has gained more interest. This can overcome the high energy band gap problem of a semiconductor such as TiO2. Furthermore, this kind of modification can widen the range of catalytic or other uses for the material. In this work TiO2 in various crystal forms was modified towards both degradation of water contamination as well as the reduction of CO2. Iron was covalently attached to TiO2 using a bottom up synthetic strategy incorporating a photoactive linker designed for photocatalytic applications. The resulting surface Fe(II)-terpyridine complex was characterized with techniques including microscopy …

The Development Of A Diiron Hydrogenase Mimic Catalyst For Efficient Dihydrogen Production, David S. Danico

Master's Theses and Capstones

Carbon dioxide has become an ever growing problem facing life on Earth due to the theory that the increase in CO2 levels has been the leading cause of global warming and could initiate significant climate change. Most of the CO2 produced by humans comes from the burning of fossil fuels for energy. Because of this, the development of a clean alternative fuel is a primary concern. Dihydrogen is looked at as a possible alternative because it has already demonstrated the ability to produce energy in fuel cells and could conceivably replace fossil fuels in every aspect of its use. The …

Synthesis Of Polycyclic Aromatic Hydrocarbons: Studies Of Aryne Cycloaddition, Acid-Catalyzed Rearrangement, And Coupling Pathways, Caitlin Hoffman

Master's Theses and Capstones

Various synthetic routes towards polycyclic aromatic hydrocarbons dibenzo[g,p]chrysene (DBC), chrysene, zethrene, and their derivatives were studied. All of these compounds are not readily available and the literature lacks facile, efficient, and scalable syntheses. Microwave flash pyrolysis (MFP) was used for the synthesis of benzyne and phenanthryne, both of which have the ability to undergo a Diels-Alder reaction at the bay region of polycyclic aromatic hydrocarbons. Phthalic anhydride was used as a benzyne precursor and 9,10-dicarboxyphenanthrene anhydride as a phenanthryne precursor. DBC was observed after the MFP of biphenyl and 9,10-dicarboxyphenanthrene anhydride, signifying phenanthryne generation. Fluoride-induced elimination and Grignard pathways were …

Evaluation Of Mercury Standard Stability For Analyzing Human Urine Using Inductively Coupled Plasma Spectrometry, Shing Lau

Master's Theses and Capstones

Quantitation of total mercury has been of great interest not only in environmental fields, but also in medical research. This is because mercury (Hg) is one of the most toxic elements, and is also a well–known global pollutant. Researchers strive to understand how toxic elements bioaccumulate in both aquatic ecosystems and terrestrial systems, along with these effect on human health. Numerous studies and analytical methods have been published for the assessment of mercury in many different sample matrices. Accurate analysis of these complex matrices is dependent on accurate and reliable analytical standards. However, the standards preparation step is time consuming. …

Major Fraction Of Black Carbon Is Flushed From New Hampshire Seasonal Snowpack Early In Melt, James Lazarcik

Master's Theses and Capstones

Seasonal snowpacks accumulate soluble impurities derived from atmospheric aerosols and trace gases throughout the winter and release them quickly early during snow melt. Previous field and laboratory studies have shown that a snowpack can lose up to 80% of the ion burden in the first 20% of the melt, an event commonly known as an ionic pulse. Other studies have concluded that particulate impurities (e.g. black carbon (BC)) concentrate in surface layers during melt which can have important implications for snowpack albedo. To characterize snow chemistry, quantify the release of impurities, and qualify enhancement effects, we collected and analyzed near …

Syntheses And Characterization Of Linearly Extended Tropylium Salts As N-Type Organic Semiconductors, Jinyu Yang

Master's Theses and Capstones

Organic semiconductors have been of interest to scientists since the 1970s. However, while much attention was focused on p-type organic semiconductors, n-type organic semiconductors were seldom reported. In this thesis, a series of linearly extended tropylium salts (LETS) were synthesized as n-type organic semiconductors and characterized by 1H NMR, 13C NMR spectroscopy, MALDI-TOF-Mass spectrometry and UV-Vis spectroscopy. The proposed synthetic strategy has proven highly suitable to synthesize LETS compounds. UV-Vis spectra of LETS in solution have been studied as well as their stability. Linear extension of the backbones has been found to be an effective way to improve the optical …

Syntheses And Characterizations Of Linearly Extended Thiazinium Salts As Organic Semiconductors, Yanmei Rong

Master's Theses and Capstones

Organic semiconductors have been the subject of both academic and industrial interest due to their potential advantages over inorganic semiconductors. Based on the type of charge transporting (hole or electron), organic semiconductors can be categorized as n-type (electron transporting) or p-type (hole transporting). Most attention has been concentrated on the development of p-type organic semiconductors and their development has led to dramatic enhancements in the performance of hole transporting material. However, the investigation and application of electron transporting organic semiconductors has not drawn as much attention. In this project, we focus on the exploration, design, synthesis and characterization of novel …

Synthesis Of Adjacent-Bridged Benzo-Annelated Cyclam And Studies Of Mono- And Di-Benzo-Annelated Cyclam Derivatives, Amanuel B. Ghidey

Master's Theses and Capstones

A new synthetic methodology for the preparation of a novel adjacent-bridged benzoannelated cyclam is presented. This methodology utilizes reductive ring expansion followed by deallylation to give the desired adjacent-bridged benzo-annelated cyclam. This novel ligand is designed to complex metal cations with a trans coordination geometry. Derivatives of this ligand can be prepared by attaching pendant arms on the nitrogens which can aid as coordinating arms and linkers for potential use of this ligand as bifunctional chelator (BFC).

Coupling chemistry studies have been carried out in an attempt to increase the lipophilicity of a dibenzo-annelated tetracyclic bisaminal and to functionalize at …

Theoretical Analysis Of The Reaction Of Peroxymethyl Radical With Atomic Hydrogen And Of Dibenzofuran With Atomic Chlorine, Mikhail Zhukovskiy

Master's Theses and Capstones

Experimental determination of rate constants for gas phase radical reactions is challenging. When rate constants necessary for modeling complex processes in atmospheric and combustion science are unknown, theoretical predictions are useful. We used Variational Transition State Theory with Multidimensional Tunneling (VTST/MT) with Density Functional Theory (DFT) to calculate the rate constant and isotope effects for reaction between the peroxymethyl radical and the hydrogen atom.

Polychlorinated dibenzofurans (PCDFs) are a group of extremely toxic compounds formed during waste incineration. Currently, their chemical degradation in the atmosphere is poorly understood. While some experimental and theoretical results regarding the reaction of PCDFs with …

Spectroscopic Investigations Of The Photochemical Properties Of I. Spiropyran On Y Zeolite For Photochromic Applications Ii. Rhenium(I) Bipyridyl Tricarbonyl On Mesoporous Zsm-5 Zeolite And Silica For Photocatalytic Reduction Of Carbon Dioxide, Kevin Dubois

Master's Theses and Capstones

Immobilization of photoactive molecules on porous and nano-sized solid supports provides unique interactions which affect photophysical properties. In situ diffuse reflectance FTIR and UV-vis spectroscopies were primarily used to investigate the properties of surface functionalized materials. Spectroscopic characterization of photochromic spiropyran molecules physically adsorbed on Y zeolite revealed the importance of surface water in controlling kinetics and reversibility of photoswitching by stabilizing the merocyanine isomer. Re(bpy)(CO)3C1 was both physically adsorbed on a mesoporous ZSM-5 zeolite and covalently bound via the bipyridyl ligand on fumed silica to generate photocatalytic CO2 reduction materials. Upon light irradiation of the solids in the presence …

Novel Synthesis Of Sulfur Based Ligands Used In Modeling Biological Hydrogen Bonding Interactions, Tyler Jesse Jacinto

Master's Theses and Capstones

Heme-thiolate proteins are known to have hydrogen bond donors proximal to the axial thiolate ligand. The specific roles of these conserved H-bond donors have not yet been elucidated. However, various sources agree upon the positive influence that increased X-H···S interactions have on protein redox potentials. For example, synthetic modeling studies of the cytochromes P450 show similar positive shifts in potential in iron-porphyrin-thiolate model systems. The ligands used in modeling the H-bonding interactions in the P450 cytochromes included a series of 2,6-substituted thiophenols, -S(2,6-(CX3CONH)2C6H3), where X = H, F, CH3. The current synthetic route to these ligands is vague and employs …

Covalent Attachment Of A Diimine Tricarbonyl Re(I) Catalyst On Solid State Nano-Material Surfaces For Solar Carbon Dioxide Reduction, He He

Master's Theses and Capstones

Reduction of carbon dioxide to useful chemicals and fuels is of significant interest. Transition metal complexes, such as tricarbonyl rhenium(I) compounds, are efficient molecular catalysts for photocatalytic carbon dioxide reduction. To improve the stability and catalytic activity of homogeneous catalysts, a mesoporous silica material, SBA-15, was synthesized and applied as catalyst support for immobilizing the tricarbonyl rhenium(I) compound via both covalent bonding and physical adsorption. The covalently bonded tricarbonyl rhenium(I) catalyst in SBA-15 exhibited excellent stability and good activity during the photocatalytic reduction process, compared with its homogeneous counterpart and the physically absorbed one. Another solid-state nano-material, Kaolin, was also …

Detection Of Trehalose In Porphyra Extracts Using Mass Spectrometry And Gas Chromatography-Mass Spectrometry, Ying Huo

Master's Theses and Capstones

It is known that trehalose helps many plants to survive under desiccated environment26. This property of trehalose has also been proposed to explain why Porphyra could survive desiccation when left on dry land for a long period of time25. However, after extensive study25, effort at identifying trehalose in Porphyra has been unsuccessful, leaving the question of whether trehalose really exists in Porphyra unanswered. In my thesis research, in collaboration with Dr. Anita Klein, I set out to use ion-trap mass spectrometry and gas chromatography coupled with mass spectrometry to identify and quantify the amount of trehalose in Porphyra extracts. Using …

The Road Less Traveled: New Chemistry Of Old Reactive Intermediates, Erin Carcella Mclaughlin

Master's Theses and Capstones

Conditions were optimized to utilize benzyl alcohol and acetate substrates in Friedel-Crafts electrophilic aromatic substitution reactions. Anhydrous iron (III) chloride (20 mol%) was shown to be an efficient catalyst when using benzene in a microwave reactor. Rapid reactions and minimal further purification make this procedure suitable for chemical library generation. We attempted to develop a synthetic route to the little known intermediate, ortho-xylallene. Though work to date has been unsuccessful, we have determined that traditional routes via allene formation may be viable. Rearrangements of terphenyls, phenyl-naphthalene, and 1,1'-binaphthalene by ipso-arenium cations were studied using triflic acid in 1,2-dichloroethane. Preferred formation …

A Model Study Of Adlayer Pattern Formation Of A Linear Molecule On Square And Triangular Lattices, Gennadiy N. Berezutskiy

Master's Theses and Capstones

We have determined patterning and geometric properties of rigid-diatomic-molecular rotors, fixed on (square and triangular) the lattice site modeled by the Morse potential. Zero-K adlayer patterns were enhanced through the implementation of unconstrained multivariable function using derivative-free method (also known as simplex algorithm). Results have been obtained over wide geometry range for adlayer patterns composed of periodically repeated primary cell.

A primary focus of this work was the calculation of adlayer free energies and geometry at the ground state. Those were obtained from conformational search of the primary (2x2) cell to locate geometric configuration, which minimizes the total energy. The …

Synthesis Of 6-Thiosubstituted Pentacenes And Study Of An Unexpected Photorearrangement Of 6-Phenylthiopentacene Dimer, Julia Y K Chan

Master's Theses and Capstones

Two new monosubstituted pentacene derivatives, 6-phenylthiopentacene, 26, and 6-acetylthiopentacene, 27, have been prepared using a dehydrogenative aromatization and elimination reaction that utilizes 1,8-diazabicycloundec-7-ene (DBU) as reagent. Although many disubstituted pentacenes have been synthesized and characterized, monosubstituted pentacenes have received much less attention. While studying the photodegradation of 26 under ambient light and air conditions, an unexpected transformation to 6,13-bis(phenylthio)pentacene, 32, was observed. The transformation requires short wavelength (254 nm) UV irradiation. Through a combined experimental and computational study, we have identified this transformation as a multi-step intramolecular process initiated by the photoexcitation of the endo anti dimer of 26. The …

The Site Of Protonation Of A Distorted Bicyclic Lactam: Nitrogen Vs Oxygen, Brian T. Sliter

Master's Theses and Capstones

Protonation of typical unstrained amides and lactams is favored at oxygen. Protonation of highly distorted lactams such as 1-azabicyclo[2.2.2]octan-2-one is favored at nitrogen. Density function theory calculations at the B3LYP/6-31G* level, as well as QCISD(T)/6-31G* calculations, predict that 1-azabicyclo[3.3.1]nonan-2-one favors protonation at nitrogen only very slightly (<2.0 kcal/mol; "gas phase") over protonation at oxygen. 1H and 13C NMR as well as ultraviolet (UV) studies of this lactam, confirm the lactam is primarily protonated at the nitrogen. Experimental spectra clearly support the N-protonated boat-chair, in contrast the calculations show the N-protonated chair-chair conformation is lower in energy. Broadened resonances in the 13C NMR spectrum suggest an exchange phenomenon. Variable-temperature studies of the 13C NMR spectra support dynamic exchange between the major tautomer (N-protonated) and the minor tautomer (O-protonated) in a roughly 4:1 mixture.

Building And Deployment Of An Automated, In Situ Greenhouse Gas Gas Chromatographic System, Andrew H. Hart

Master's Theses and Capstones

High-precision, continuous monitoring of greenhouse gases, such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N 2O), sulfur hexafluoride (SF6), and the criteria pollutant carbon monoxide (CO), is important for characterizing their regional sources and sinks and understanding how their ambient levels are changing with time and associated anthropogenic activities. For monitoring this suite of gases, a fully automated gas chromatographic based analytical system was built and deployed in the field at the UNH AIRMAP Observing Station at Thompson Farm in Durham, NH. The instrument consists of a Shimadzu 17A gas chromatograph (GC), equipped with a Flame Ionization Detector and …

High Energy Routes To Reactive Intermediates: Computational And Experimental Studies, Aida Ajaz

Master's Theses and Capstones

We developed microwave flash pyrolysis (MFP), using graphite and other sensitizers to carry out high temperature reactions. Newly developed is a closed vessel MFP method. Studies to date include isomerization of azulene to naphthalene, generation of benzyne, cycloaromatizations, and rearrangements. New thermal sensitizers included silicon carbide, titanium dioxide and diverse metal oxides. Graphite remains the most effective thermal sensitizer. Sealed tube MFP was utilized to investigate the Brown rearrangement of aryl alkynes. CCSD(T)//M05-2X computations have been carried out for both concerted and stepwise mechanisms in dehydro-Diels-Alder reactions of ethene and ethyne with vinylacetylene and 1,3-butadiyne. Concerted transition states for enyne-ene …

The Effect Of In Vivo Pbde Treatment On Hepatic Phosphoenolpyruvate Carboxykinase (Pepck) Enzyme Kinetics In Male Wistar Rats, Jessica T. Nash

Master's Theses and Capstones

Polybrominated diphenyl ethers (PBDEs) are synthetic flame-retardant chemicals that enter the environment and mammalian body and may disrupt glucose metabolism. This study investigated the effect of PBDEs on a key gluconeogenic enzyme, phosphoenolpyruvate carboxykinase (PEPCK). Forty-eight male Wistar rats were gavaged with corn oil or corn oil containing 14 mg/kg DE-71 for 3, 14 or 28 days (N = 8 per group). At each time point, fasting plasma glucose, insulin and C-peptide were measured and liver PEPCK enzyme activity was assayed. PBDEs significantly decreased PEPCK Vmax (mumol/min/g liver weight) at 3 days by 26%; this reduction persisted through 28 days. …

Synthesis Of 1,4,7-Triazacyclononane Pendant-Armed Chelators And Their Metal Complexes, Elizabeth Garcia Cardona

Master's Theses and Capstones

Pendant-armed cyclic polyamines have been demonstrated to be promising ligands for the development of new metal-based radiopharmaceuticals for positron-emission tomography (PET). Macrocyclic polyamines bearing pendant arms can effectively bind specific metals with suitable complexation kinetics and stability while attached to a tumor-targeting vector or peptide. 64Cu-radiolabeled peptides containing the chelator 1,4,7-triazacyclononane 1,4,7-triacetate have been shown to possess superior properties which overcome commonly observed problems such as demetallation and accumulation of the radio-metal in non-targeted tissues. To model these radiolabeled bioconjugates and to gain insight into this observed bio-stability, the synthesis of a copper (II) complex of a new triazacyclononane derivative …

Measuring Paralytic Shellfish Toxins In Mussels From New Hampshire Coastal Waters Using Zwitterionic Hydrophilic Liquid Chromatography/Electrospray Mass Spectrometry, Lee Lee Chung

Master's Theses and Capstones

A liquid chromatography/mass spectrometry method (LC/MS) has been adapted from the literature to provide a rapid, direct and highly sensitive routine assays for several Paralytic Shellfish Poisoning (PSP) toxins, with detection limits in the ppb range for STX and its analog neosaxitoxin (NEO) and decarbamoyl saxitoxin (dcSTX). A high throughput sample clean-up aided in reducing the effects of the matrix. Method validation and stability studies have been performed to show that reliable results are produced by this LC/MS method. The LC/MS method was found to supplement the mouse bioassay with the ability to determine the levels and specific types of …

Regulation Of Photoreceptor Phosphodiesterase By Prenyl Binding Protein And By Other Interacting Proteins In Photoreceptor Cells, Hannah J. Gitschier

Master's Theses and Capstones

Photoreceptor phosphodiesterase (PDE6) is a central component of the visual pathway. While initial PDE6 activation following light stimulation of photoreceptors is well understood, regulation of PDE6 during recovery and light adaptation may require additional components that interact with PDE6. Two approaches were taken to characterize these potential interactions. The first explored the interaction of PDE6 with prenyl binding protein (PrBP/delta) and demonstrated that changes in membrane localization of PDE6 may occur during light adaptation as a result of association with PrBP/delta. The second approach characterized the PDE6 "interactome" by a mass spectrometric identification of 75 proteins that co-purify with PDE6 …

Trivalent Metal Complexation Of Pendant-Armed Cross-Bridged Cyclams, Han Wang

Master's Theses and Capstones

Radiopharmaceuticals are radioactive compounds which are used in radiotherapy or diagnosis. They have attracted a great deal of attention over the last decades for molecular imaging. Coordination chemistry also plays an important role in designing metal-based radiopharmaceuticals. A novel class of tetraazamacrocycle ligands where two non-adjacent nitrogens are bridged by an ethylene cross-bridge show good thermodynamic stability and high kinetic inertness in their metal complexes. Seven trivalent metal (Y3+, La3+, Ga3+, In3+) complexes of cross-bridged ligands have been synthesized and characterized. Two vanadyl complexes were prepared as well. All metal complexations have been investigated under microwave-assisted conditions. Both Ga-CB-TE2P and …

Truncated Mortalin In Animal Cancer, Katrina K. Olson

Master's Theses and Capstones

Hematopoetic neoplasia or clam hemocyte cancer (a leukemia-like disease) has been studied in a number of bivalve molluscs for the last 20 years. Recent molecular studies of the hemocytes of the soft shell clam, Mya arenaria, have demonstrated an interaction between p53 and mortalin, the mitochondrial Hsp70. The former protein is intimately involved in the initiation of cell-cycle arrest, apoptosis, DNA repair, and cell differentiation. In cancerous clams, wild-type p53 is sequestered in hemocyte cytoplasm by mortalin and cannot be translocated to the nucleus. This is critical because although p53 is functions properly, it is unable to enter the nucleus …

A Versatile Synthetic Approach Towards The Synthesis Of New Polycyclic Aromatic Hydrocarbons Using Scholl, Grignard And Umpolung Chemistries, Joseph M. Dunn

Master's Theses and Capstones

The Synthesis of Dibenzo anthracenes 3, 7-diphenyldibenzo[a,h] anthracene (1) and 3,6-diphenyl-9-methoxydibenzo [a,j] anthracene ( 2) as well as a phenyl substituted picene (3) was attempted utilizing an original, generic, scheme. An Umpolung reaction between a 1,3-dithiane and a variety of dibromomethyl benzene hubs was performed to generate the carbon framework of 1, 2 and 3. Deprotection of the thioacetal groups yielded a carbonyl product which upon Grignard addition and dehydration could potentially be converted to the desired product. The proposed synthetic design allows for a variety of substitution patterns about the parent PAHs, without adding synthetic steps.

Investigating Pheromone Variability In A Terrestrial Woodland Salamander, Adam James Chowinard

Master's Theses and Capstones

The communication system of Plethodontid salamanders relies heavily upon chemical signaling. Pheromone molecules convey a tremendous amount of information to conspecifics, and facilitate a wide variety of the essential social functions of these animals. Much of the information contained within the pheromone mixture is variable from one individual to the next, such as the ability to recognize specific individuals, the size of the sender, and the relative "quality' of the signal. In order for variable information to be conveyed through chemical signals, the corresponding variability must be contained within the pheromone mixture itself. This variability may exist as a gradient …

Design And Implementation Of A Statistical Analysis Tool For Two Biological States, Gang Lu

Master's Theses and Capstones

The major goal of research in this thesis is to design and implement a software tool (Q5+) that can easily, quickly and reliably search biomarkers by statistically analyzing mass spectrometry data from two different biological states. Q5+ implements most of the Q5 algorithm, a very good algorithm that is used for classifying mass spectrometry data (Lilien et al). Compared Q5 Q5+ improves the usability of Q5 by incorporating a Graphic User interface and Matrix Library. Results show that by running the same data, Q5+ and Q5 showed the equivalent classification ability. Q5+ also implements the Peak Screening feature, which can …

N-Linked Glycans Characterization And Biomarker Discovery By Sequential Mass Spectrometry, Hongqin (Jenny) Jiao

Master's Theses and Capstones

N-linked glycans from a well-studied glycoprotein, (hen albumin) were characterized using ion trap MS (MSn) without chromatographic separation. From the spectral profile, ten major ion compositions were selected for study, which resulted in the characterization of 37 isomeric structures, 16 of which were previously unreported. These findings were compared with previously reported studies using different analytical strategies: IMMS, MS/MS. MSn not only identifies but also structurally characterizes components in the absence of any adjunct instrumentation. Selected examples have been detailed.

A major challenge for adult stem cell (ASC) research is the lack of specific biomarkers for their identification and isolation. …