Chemistry Commons^™

Antioxidant Activity Of Pamam Dendrimer Stabilized Ascorbic Acid, Gabriella Srikureja

Honors Theses

Ascorbic acid (vitamin C) is an essential micronutrient for human health. It acts as an enzymatic cofactor in anabolic biochemical pathways such as the synthesis of collagen, dopamine, and norepinephrine. Unfortunately, this versatility comes at the cost of a high degradation rate both in and outside of the food matrix. Previous research exploring stabilizing aqueous ascorbic acid through Poly(amidoamine) (PAMAM) dendrimers found success in reducing the rate of degradation.

To confirm the antioxidant activity of ascorbic acid in its stabilized dendrimer complex, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assays examined via Cary 5000 UV-Vis-NIR spectrophotometer found that performing the DPPH assay under aqueous conditions …

One Peak, Two Peaks: On The Effects Of Enhanced Evaporation In An Ammonium Sulfate And Succinic Acid Aerosol System, Julia Reynolds

Honors Theses

Aerosols, defined as suspensions of liquid or solid particles in a gaseous medium, are ubiquitous in both indoor and outdoor environments. They have significant impacts ranging from public health concerns to climate dynamics. In laboratory settings, aerosols are most often generated through a technique known as atomization. The atomization or nebulization is from dilute, aqueous solutions of various chemical compositions. This process typically produces a unimodal, lognormal particle size distribution with exceedingly rare exceptions. Colleagues in a different laboratory (Dr. Freedman’s Group at Pennsylvania State University), however, mentioned they observed a bimodal size distribution, a distribution with more than one …

Theoretical Investigation Of Hydrogen Abstraction From Fluorinated Propanones And Fluorinated Propanals, Laurel Washburn

Honors Theses

Per- and polyfluoroalkyl substances (PFAS) are a class of thousands of industrially used compounds often called “forever” chemicals because of their slow degradation process that leads to accumulation in soil, dust, drinking water, and the body. PFAS are used for their grease and water resistance properties but some of these compounds are toxic at extremely low levels. To better understand the effects of these types of compounds, the main pathways of their degradation need to be further investigated. This study analyzes computationally the hydrogen abstraction reactions by both hydroxyl radical and triplet oxygen atom for all possible fluorinated propanones and …

Characterization Of Aromatic Stationary Phases For Uses In High Performance Liquid Chromatography, Anastasia Davis

Honors Theses

High Performance Liquid Chromatography (HPLC) is an analytical chemist technique used to separate a sample into its components to characterize and study a specific molecule or compound. Traditionally, High-Performance Liquid Chromatography in different industries, such as the environmental and pharmaceutical fields, uses stationary phases that are already well characterized, such as the C18 stationary phase for separation. However, aromatic stationary phases have recently been produced, which have phenyl groups bonded to the interior surface of the column. Still, they have not been well characterized because of how modern they are. This project characterized several aromatic stationary phases (Biphenyl, pentafluorophenyl, and …

Theoretical Spectroscopic Predictions Of Electronically Excited States, Noah R. Garrett

Honors Theses

The quest for faster computation of anharmonic vibrational frequencies of both ground and excited electronic states has led to combining coupled cluster theory harmonic force constants with density functional theory (DFT) cubic and quartic force constants for defining a quartic force field (QFF) utilized in conjunction with vibrational perturbation theory at second order (VPT2). This work shows that explicitly correlated coupled cluster theory at the singles, doubles, and perturbative triples level [CCSD(T)-F12] provides accurate anharmonic vibrational frequencies and rotational constants when conjoined with any of B3LYP, CAM-B3LYP, BHandHLYP, PBE0, and ωB97XD for roughly one-quarter of the computational time of the …

Synthesis And Analysis Of A Novel Magnetic Surfactant, Donovan Turpin

Honors Theses

Researchers in the University of Mississippi Chemical Engineering Department have suggested that chelation of a large magnetic transition metal, namely dysprosium, into the large polar head group of a surfactant could result in a magnetic surfactant. This project was aimed at synthesizing a surfactant with a large enough head group and negative charge (specifically EDTA) to support this ion and demonstrating that the chelation process was successful. If so, the molecule would ideally be capable of forming micelles which could extract oily substances from water using a strong magnet—possibly applicable to environmental crises like oil spills.

NMR analysis has suggested, …

Synthesis And Characterization Of Ox-Nad Derivatives, Juanita Monteiro-Pai

Honors Theses

Energy metabolism is complex, and NAD, or nicotinamide adenine dinucleotide, plays a huge role as an organic redox cofactor, driving metabolic reactions. The abundance of pathways dependent on NAD has led to an increase in the studies of NAD and its precursors. As a result NR, or nicotinamide riboside, is now a popular pharmaceutical taken to increase levels of NAD in the body. NR is not only a precursor to NAD, but a metabolite that is found in extracellular regions such as urine and blood. While this molecule should be an intracellular molecule, the fact that it is found in …

The Synthesis And Characterization Of 9,10-Bis-(Iodoethynyl)Anthracene For 2d Molecular Crystals From Halogen-Bonding, Nehemiah Antoine

Honors Theses

Two-dimensional crystals have unique properties, giving them the potential to develop practical items such as electronics, biomedicine, and sensors. Our goal is to use chemical principles to synthesize molecules that spontaneously form 2D crystals with designed patterns and properties. For this, we will exploit directional, non-covalent interactions to determine what pattern will form in 2D. In this project halogen-bonding will be utilized: halogen-bonding is the interaction between the electrophilic region of a halogen and a nucleophilic region of a Lewis base. We are functionalizing anthracenes with iodine and nitrogen to form halogen bonds that enable the molecules to pack more …

Synthesis And Characterization Of Silver(I) And Manganese(Ii) Complexes With Thione Imidazoles, Shannon Keyser, Audrey Lawrence, Jaime M. Murphy Ph.D.

Honors Theses

Coordination polymers are chemical complexes with versatile applications such as catalysts, electrical conduc-tors, non-linear optics, magnetics, chemical sensing, and molecular storage. The polymers are comprised of a repeating series of metal-ligand complexes, which form various structures in varying ratios depending on the metal and ligand used. Certain metal-ligand combinations have shown particular promise as potentially being polymers or, if not polymers, possessing other useful features such as electromagnetic conductivity. Complexes were synthesized using silver(I) and manganese(II) with the ligands methimazole, 2-mercaptoimidazole, and thiocarbanilide with counterions of either chloride or nitrate. These com-plexes were characterized using elemental analysis, infrared spectroscopy, and …

Methods For Computing Rovibrational Spectral Data With Applications To Inorganic Oxides And Hydrocarbons, Alexandria Watrous

Honors Theses

Computational chemistry focuses on finding solutions to the time-independent Schrödinger equation for systems of interest to study their molecular properties such as rovibrational spectral data. Any molecule containing more than one electron cannot be solved explicitly but coupled cluster theory offers one of the best approximations. One such application of this method is to molecules of astrochemical interest to support observation and experimental data. Chapters 2, 3, and 4 look at the performance of new couple cluster theory methods including composite and hybrid methods for ground and excited state rovibrational data. Chapters 5 - 9 use the previously mentioned methods …

Understanding The Mechanism Behind Hfip's Effect On Diastereomeric Separation Of Oligonucleotides, Ian Neidigh

Honors Theses

The goal of this research was to determine the mechanism behind 1,1,1,3,3,3-hexafluoroisopropanol's (HFIP0 ability to suppress the separation of oligonucleotide diastereomers. This was accomplished by selecting different molecules that were like HFIP but differed in specific ways such as polarity, number and type of halogen(s), alcohol group location, carbon chain length, hydrophobicity, and chao/kosmotropicity. These molecules replaced HFIP in an IPRP chromatography method to determine if splitting of the diastereomers was observed and then they would becompared to HFIP's effect. Viscosity tests were to run to acquire quantitative data to determine chao/kosmotropicity. No decisive trend among a single factor was …

Computational Study Of Substituent Effects On The Diels-Alder Reaction Involving Furan And Maleimide For Hydrogel Synthesis, Matthew Phillips

Honors Theses

This research utilized a computational study with SPARTAN’20 software to analyze the energetics of the Diels-Alder (DA) reaction between substituted furan and maleimide. The products of this type of reaction can lead to the production of hydrogels. Hydrogels are used in multiple biomedical applications, such as controlled drug delivery systems, wound dressings (liquid bandages), contact lenses, and more. The DA reaction involves a diene (a hydrocarbon with two conjugated π bonds) and a dienophile (a hydrocarbon with one π bond). Research on the placement of electron withdrawing and electron donating groups onto the dienophile and diene has been completed in …

Phenanthrene Jamboree, Alexander D. Roth

Honors Theses

Using cyclopropanated and cyclobutanated phenanthrene precursors, our hero embarks on a mission to find as many reactive intermediates as possible. Fraught with danger, romance, and mangosteens, Anderson calls this work 'monstrous' and 'alarming.'

Self-Quenching Of Carbon Monoxide In The Presence Of Noble Gases, Madeline V. Hinkle

Honors Theses

Precise rate coefficients for the vibrational relaxation pathways of CO(v)-CO in the presence of Ar and Kr have been determined through the work of this thesis. This work was motivated by the need to find a more cost-effective alternative to using xenon as a bath gas, which has increased significantly in price in the past few years. Similar experiments within this lab at Bucknell have been conducted in the past using argon, which can be used in the same manner as xenon but comes at a much lower price, but the experiments yielded inferior results compared to those using xenon. …

Computational Study Of Proton Transfer At Transition Metal Hydrides, Megan Ford

Honors Theses

Energy storage in the bonds of common chemical feedstocks is an attractive solution to the unreliability of wind and solar power due to its long term efficiency and easy recoverability. Energy is stored by reducing chemicals like ammonia, formic acid, and hydrogen, the reaction of which is dependent on a catalyst. To catalyze the reaction, the catalyst undergoes a slow proton transfer (PT) step to form what is known as a metal hydride. The sluggish kinetics of this step lower the effectiveness of the catalyst, and therefore must be better understood in order to improve the efficiency of energy storage …

An Investigation Of The Correlation Between Polymer Solution Entanglement And Electrospun Polycaprolactone Fiber Mechanics, Manasa Sujatha Rajeev

Honors Theses

The aim of this study was to determine the role of entanglement in the mechanical properties of electrospun polycaprolactone (PCL) fibers. PCL is a useful polyester due to its favorable properties such as its biocompatibility and biodegradability. Multiple concentrations of PCL were dissolved in a 3:1 acetic to formic acid solvent. Fibers were formed using an electrospinning technique. Entanglement is a required parameter to produce fibers, thus the number of entanglements per polymer (ne) was calculated, as well as the corresponding concentrations. Smooth continuous fibers were found to form between 13 w/v% and 17 w/v%. Mechanical analysis, such as three-point …

The Effect Of Solvent Identity And Hydride-Donor On The Reduction Of Co2 Into Useful Fuels, Abigail Mcentire

Honors Theses

One possible strategy for decreasing CO2 emissions is through electrocatalytic reduction reactions to convert the CO2 back into combustible fuels , such as methane or methanol. However, it can be challenging to control the reaction to select one of these useful fuels as opposed to carbon monoxide or formate. Our strategy is to investigate a specific hydride donor and solvent combinations for which the reaction favors conversion to methanol. It was found that in acetonitrile , several hydride donors were capable of selective reduction of CO2 to the methanol oxidation state.

Exploration Of Sulfonamides And Benzothiazoles As Peptide-Based Cleavable Linkers, Abigail Dalton

Honors Theses

Cleavable linkers have demonstrated great potential in various applications of medicinal organic chemistry, such as in modern therapeutic development. Linkers are stable compounds that cleave in specific conditions to release molecular cargo. We have developed cleavable linkers based on nucleophilic aromatic substitution reactions on sulfonamide and benzothiazole substrates in small molecule and in peptide studies. Sulfonamides, commonly with an electron-withdrawing group, reacted in high conversion of starting material to the sulfide product in small molecule studies, but was unable to successfully cleave the sulfonamide linker on peptide in mild conditions. Next, a benzothiazole sulfone substrate was analyzed and optimized in …

Investigation Of Zinc And Iron In Wildflower Honey, Savannah Simpson

Honors Theses

Honey acts as a valuable food source for both animals and humans. When found in contaminated environments, there is an increased likelihood that honey samples will have high metal concentrations. It has been discovered that honey concentrations in metals can be different based on location. This experiment aims to determine the amount of two valuable metals, zinc, and iron, in various honey sources. These metals can be important to the human body because they help boost immunity and allow the body to carry out the functions required for survival. However, if these elements are present in copious quantities, then it …

Stress-Sensing In Flexible Epoxy Adhesives, Christine Rukeyser

Honors Theses

In mechanochemistry, mechanical force causes a chemical change using small molecules, called mechanophores, by covalently connecting them into polymer materials. Stress-sensing mechanophores give a visual signal of mechanical force on the molecular level within a material. To our knowledge, stress-sensing mechanophores have never been incorporated into a commercially available epoxy kit. In this work, the characterization of two 3MTM Scotch-Weld TM Epoxy Adhesive kits: DP100 Plus Clear and DP190 Translucent have been completed through FT-IR Spectroscopy. The addition of the mechanophore spiropyran to the 3M kits will be discussed; as well as preparation and characterization of three dimerized anthracene derivatives. …

Understanding Favorability In Diels-Alder Reaction For Hydrogel Synthesis: A Computational Study, Sejal Bhasin

Honors Theses

This study delves into analyzing the change in reaction enthalpy and activation energies of the Diels-Alder reaction for the synthesis of hydrogels, possessing diverse applications in scientific domains due to their unique properties. Utilizing the Diels-Alder reaction for hydrogel creation allows tailored structures responsive to specific stimuli. Theoretical calculations, employing computational methods, utilized the latest Spartan software (version 20) and conducting gas-phase calculations with semi-empirical methods (PM3) and Hartree-Fock (6-31G*). This research examines the hypothesis regarding the potential enhancement of reaction favorability through the introduction of an aromatic ring into the product, along with the incorporation of an electron-donating group …

Chemical And Genetic Composition Analysis Of Organic And Nonorganic Tortilla Chips, Aubrey White-Day

Honors Theses

The aim of this study was to explore the chemical and genetic differences between organic and nonorganic tortilla chips using GC-MS and PCR. Twenty chip brands were selected: 10 organic and 10 nonorganic. A survey on shopping preferences was created and distributed to compare results of public opinion to experimental data. It yielded 212 responses. All organic chip brands, and one out of ten nonorganic chip brands, tested negative for GMOs. This study concluded that there are minimal chemical differences based on Jaccard similarity indicies and stark genetic differences between organic and nonorganic tortilla chips. In comparing statistical analyses to …

Photophysical And Photochemical Processes In Small Molecules And Materials For Solar Energy Conversion, Ethan Lambert

Honors Theses

The work covered in this thesis all falls under the theme of photophysical processes after light and matter interact. Those of primary interest are Raman scattering induced vibrations and excited state dynamics probed by transient absorption spectroscopy. Small molecules are studied with Raman spectroscopy and computational chemistry. These studies unearth the shifts in vibrational frequency as a function of charge transfer or receipt and how a quantitative assay of natural orbital populations and delocalization can offer both the nature and magnitude of this charge transfer. Further, a method is presented that builds upon previous work within the academic family tree; …

Microhydration Of Hexachlorophosphate Anion, Anna Robertson

Honors Theses

The microhydration of the hexafluorophosphate anion has been the focus of many previous experimental and computational studies, due to its use in room temperature ionic liquids.This preliminary study examines the analogous hexachlorophosphate anion and its interactions with one to two water molecules (PCl₆⁻(H₂O)_n, n = 1-2), identifying the structural and energetic differences in the microhydration of PCl₆⁻ versus PF₆⁻. A systematic investigation of the possible orientations of one to two water molecules around PCl₆⁻ was done. Full geometry optimizations were performed using the ab initio method …

Diffusion Of Ionic Liquid-Modified Polymer Nanoparticles Through Nasal Mucus, Mary Vanlandingham

Honors Theses

Mucosal barriers are a natural defense system for preventing the entry of foreign objects into the body; however, they pose as obstacles for effective drug delivery. Coated polymer nanoparticles have been proven to possess improved rates of diffusion across mucus compared to their uncoated, or bare, counterparts. When choline-based ionic liquids (ILs) are introduced to an aqueous system, their dissociation leads to an increase in solution conductivity which ultimately reduces the viscosity of mucus without significantly affecting its structure. Additionally, ILs are highly tunable, so they work well in a range of pHs and conductivities, making ILs an ideal choice …

Investigating Reactivity Of Artificial Copper Peptides With Small Molecules, Allyson Bryant

Honors Theses

The design of artificial enzymes has been a topic of significant interest in the field of biochemistry, as they can provide new opportunities for catalytic processes and drug development. De novo protein design has emerged as a promising approach to create such enzymes, and the study of metalloproteins, particularly copper-binding peptides, has become a focus of this research. This thesis investigates the reactivity of a mutated copper-binding peptide, I5A-3SCC, with oxygen and its implications in the development of artificial enzymes.

The parent peptide, 3SCC, was mutated by replacing Isoleucine residues with smaller Alanine side chains, which was hypothesized to enhance …

Photocatalyzed Hydrogen Evolution Using Nickel-Bound Metallothionein Protein, Windfield Swetman

Honors Theses

The continued burning of fossil fuels is not only a cause of increasing deterioration of the environment but also a financially unsustainable source of energy. Advances in energy production must be investigated to avoid the long-term effects of this current main source of energy. One of the avenues being explored is the use of metalloenzymes to catalyze hydrogen evolution via water splitting that occurs during the reductive half of artificial photosynthesis. Metalloenzyme catalysts with a single Ni(Cys)₄ active site have been previously studied, and this study explores the possibility of increasing hydrogen production by using metalloenzyme catalysts with multiple …

Structural Integrity And Stability Of Dna In Ionic Liquid And Near-Infrared Indolizine Squaraine Dye, Ember Yeji Suh

Honors Theses

Luminol, the most common presumptive test for blood at a crime scene, has multiple issues, such as false positive results with chemical agents, no luminescence due to “active oxygen” cleaning agents on bloodstains, and inability to penetrate textile materials. A combination of indolizine squaraine dye and ionic liquid (IL), or Dye Enhanced Textile Emission for Crime Tracking (DETECT), have shown potential to address these issues. The purpose of this study was to assess the binding mechanism of CG (1:1) and SO₃SQ dye to HSA and how the mechanism can explain the W214 fluorescence quenching effect and to determine …

A Synthetic Approach To The Optimization Of Silicon-Rosindolizine Swir Fluorophores, Timothy Lewis

Honors Theses

Fluorophores emitting within the near-infrared (700 – 1000 nm) or shortwave-infrared (1000 – 1700 nm) regions of the electromagnetic spectrum are of particular interest for their potential to supplement or even outright replace commonly used biological imaging techniques, such as magnetic resonance imaging and computed tomography scanning. Various characteristics make these molecules particularly appealing to researchers, such as their ease of synthetic tunability, generally low toxicity, and high solubility in biological media in comparison to other NIR- and SWIR-emissive fluorophores. Different molecular skeletons have been examined for use as the core of these imaging agents, such as squaraine, cyanine, and …

Design And Synthesis Of Dinucleating Phthalazine-Based Ligands Toward Bimetallic Ruthenium Catalysts For Water Oxidation, Alex Bromley

Honors Theses

Two synthetic pathways were developed to construct dinucleating ligands towards the synthesis of bimetallic ruthenium-based water oxidation catalysts. The motivation for this work stems from earlier observations of related ligands that are susceptible to oxidative decomposition. The design pursued here incorporates a phthalazine core into the dinucleating ligand, which, we hypothesize, will prevent the previously established cleavage of a pyridazine unit at the same position. The ligand precursors involved in the multi-step syntheses are characterized by Nuclear Magnetic Resonance (NMR) spectroscopy. Synthetic protocols were refined to ensure reproducibility. In addition, our hypothesis for which of the two target ligands will …