Chemistry Commons^™

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 …

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; …

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 …

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 …

Synthesis And Characterization Of Rhenium 2,2′-Pyridylnaphthyridine Metal Complexes, Benjamin F. Solomon

Honors Theses

Rhenium (Re) is a group 7 heavy 5d transition metal in the same family as manganese (Mn) and technetium (Tc). Re-carbonyl complexes are known to be catalysts for many different kinds of reactions from C-C bond formation to reduction reactions like CO₂ reduction (CO₂RR)^1,2. With this in mind, we have prepared a set of six Re-carbonyl complexes of 2,2′-pyridyl-1,6-naphthyridine (1,6- pynap) and 2,2′-pyridyl-1,8-naphthyridine (1,8-pynap), a redox non-innocent ligand containing a bpy moiety as well as an additional aryl nitrogen binding location at which another metal-ligand bond could form. We have synthesized these complexes as precursors …

Synthesis And Characterization Of Organometallic Complexes For Biological Imaging, Emily Stumbo

Honors Theses

Luminescent transition metal complexes are of interest for biological imaging applications due to their unique photophysical properties including large Stokes shift, long fluorescence lifetimes, and tunable emission. Altering ligand structure is a useful way to manipulate the charge transfer (CT) and mixed character states that give these complexes their photophysical properties. A series of organometallic complexes containing ligands with externally facing nitrogens has been prepared and synthesized. Complexes of the form Pt (II)(tbbpy)(C2-py), Re(CO)3(N^N), Ir(C^N)2(N^N), and Ir(C^N)2(N^O) have been studied for their potential application as biological imaging agents. The goal of this project is to compare the properties of these …

Synthesis And Characterization Of Silver Thione Complexes, Audrey V. Lawrence

Honors Theses

Coordination polymers are repeating units of a coordination complex that have applications as catalysts, conductors, and magnets. In this work, silver (I) was the metal of choice because it behaves similarly to copper (I), which has been studied much more extensively and thione ligands were chosen due to their potential for forming coordination polymers. These coordination complexes with silver were synthesized by combining silver nitrate with thioacetamide, N,N'-diphenylthiourea, and 2-mercapto-1-methylimidazole. These complexes were characterized via IR spectroscopy, elemental analysis, and X-ray crystallography. Silver thioacetamide was determined to form a coordination complex through the sulfur to form a trigonal crystal lattice …

Synthesis And Characterization Of Redox-Active Multidentate Ligands For Catalytic C-H Bond Oxidation And Carbon Dioxide Reduction, Caroline Hodge

Honors Theses

This thesis focuses on two research projects. The first project reported in Chapter 1 involves the synthesis and application of a tetradentate ligand (2-(1,1-di(pyridin-2-yl)ethyl)-1,10-phenanthroline, PhenPY2Me) that is metalated with iron to give a catalyst capable of carbon-hydrogen (C-H) bond oxidation. C-H bond oxidation provides a method that may allow some transformations in organic syntheses to be streamlined. The mononuclear iron complex supported by PhenPY2Me was found to dimerize in the presence of O₂ in a non-coordinating solvent. These iron complexes and a previously reported system were assessed and compared in C-H bond oxidation with model substrates using the sacrificial …

A Conductivity Analysis Of A Newly Synthesized Poly(Ethylene Glycol) Methyl Ether Hydroxide Electrolyte, Sarah Marie Peterson

Honors Theses

This thesis investigates the synthesis and conductive properties of a Poly (ethylene glycol) methyl ether-based polymer electrolyte. The goal of the synthesis is to enhance the hydroxide ion conduction properties of the polymer with its cationic groups attached. The MePEG backbone contained seven ethylene glycol groups and was modified to substitute the hydroxide group in the MePEG with trimethylamine. In addition, the bromide added in the synthesis was exchanged for hydroxide ions to allow for the transportation of hydroxide ions in polymeric electrolytes that can be used in Anion Exchange Membrane Fuel Cells. The newly synthesized polymer was compared to …

Functionalization Of Novel Pp5 Inhibitors, Hope P. Hill

Honors Theses

The overexpression of protein phosphatase 5 has been correlated to tumor cell reproduction making it a candidate for small molecule drug therapy. Selective and potent inhibition of protein phosphatase 2A (PP2A) enzyme has been previously achieved through the development of the molecule fostriecin with key functionality being a lactone and unsaturated linear chain. The large synthetic overhead of fostriecin has led to exploration of other small molecule inhibitors that could mirror fostriecin’s interaction with the active site in the catalytic domain of PP5. The naturally occurring inhibitor, cantharidin, is functionalized with an epoxy containing eleven carbon chain to optimize binding …

The Synthesis Of A Mepeg-Based Hydroxide Conducting Electrolyte And The Optimization Of The Mepeg-Tosylation Reaction, Andrew Ladner

Honors Theses

As society is becoming increasingly aware of the effects of climate change and the ever-looming threat of a fuel shortage, exploring green and renewable alternative energy production, such as fuel cells, is paramount. This project investigates the synthesis of a polyethylene glycol monomethyl ether (MePEG_n) based polymer as well as the optimization of the MePEG Tosylation reaction. The MePEG explored contains seven polymerized ethoxy groups (MePEG₇). The MePEG₇ polymer was modified by substituting a positively-charged trimethylamine group in the place of the alcohol functional group at the end of the PEG chain. The reason for …

Synthesis And Characterization Of Transition Metal Scorpionate Complexes For Redox Shuttle Applications In Dye-Sensitized Solar Cells, Chase Lance

Honors Theses

Given the rising global energy demands, alternative renewable energy sources are currently being investigated. The most appealing renewable energy source is solar energy, and dye-sensitized solar cells (DSSCs) in particular are an attractive technology. DSSCs have traditionally utilized iodide/triiodide as the redox mediator couple, which exhibits high efficiencies and fast regeneration of the oxidized dye with little recombination. Recently, the use of alternative redox couples based on transition metal complexes has been studied as a promising substitute due to the tunable design of these complexes. In this study, tridentate tris(pyrazolyl)borate and tris(pyrazolyl)methane ligands with first-row transition metals were designed and …

Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr.

Honors Theses

In this project, the vibrational characteristics/vibrational modes are explored via Raman Spectroscopy for thiolated-gold nanoparticles. This class of compounds is also known as gold nanoparticles (AuNPs). They remain of great interest in research areas such as catalysis, gold dependent nanoelectronics, drug delivery, and sensing, due to their unique size-dependent optical, chiroptical, and electronic properties. Vibrational spectroscopy of thiolated gold nanoparticles are oftentimes considered nontrivial as the compounds strongly absorb light in the visible region of the electromagnetic spectrum, are generally considered weak scatterers, and give off large amounts of fluorescence. This combined with their black appearance, susceptibility to localized heating, …

Towards The Synthesis Of An Artificial Fluorescent Siderophore, Ashley Burns

Honors Theses

Siderophores are molecules capable of binding ferric ions with high affinity (Ka = 1052). This thesis outlines our attempts to synthesize an artificial siderophore, which incorporates a signaling group to help monitor the uptake of ferric ions. The artificial siderophore is a tripodal molecular receptor synthesized in a five-step procedure with a proposed final sixth step. Rhodamine 6G azide (95.0% yield) was formed from rhodamine 6G and the synthesis of 2-azidoethanamine was modified from the literature. The tripodal arm portion of the sensor was successfully synthesized by protecting the catechol of 2,3-dihydroxybenzaldehyde to form 3-formyl-1,2-phenylene dimethanesulfonate (98.8% yield). The reduction …

Optimization Of Superhydrophobic Surface Production Using Ambient-Dried Silica-Based Aerogels, Elizabeth Donlon

Honors Theses

Superhydrophobic surfaces exhibit particular properties that make them functional in various anti-sticking, anti-contamination, self-cleaning and drag reduction applications. Though such surfaces are found in nature - most notably the lotus leaf - they are difficult to produce. There are numerous methods and techniques for fabricating superhydrophobic surfaces. One such method is the sol-gel method, in which aerogel, a highly porous and lightweight material that can be made hydrophobic or superhydrophobic, is coated onto a surface. The purpose of this project is to devise a simple and repeatable procedure for making hydrophobic silica aerogel coatings that can be used for drag …

Photoelectrochemical Investigations On Novel Earth Abundant Solid State Catalysts For Solar Water Oxidation, Nathaniel Branimir Kurtz

Honors Theses

In light of a looming fossil fuel scarcity, many forms of alternative, clean energy production are being researched in order to provide a more sustainable source of energy production for the future. One area of research is on using novel, abundant catalytic materials in conjunction with semiconducting materials to drive the splitting of water in order to produce hydrogen gas, an energy-rich fuel. Currently, efficiency is limited by the energy bottleneck posed by the oxygen evolution reaction (OER) half of water splitting. In this work, cobalt selenide (CoSe) catalyst paired with the semiconductor iron oxide (Fe2O3) has been identified as …

A Chemical Sensor For Cyanide, Rachel E. Lambert

Honors Theses

The cyanide ion and its gaseous form, hydrogen cyanide, are extremely toxic. Cyanide impairs cellular respiration by inhibiting cytochrome c oxidase, an enzyme in the electron transport chain, leading to cell death.

In a previous study, we synthesized an optical sensor that detects cyanide selectively. The aim of this project is to increase the sensitivity of this sensor. This can be achieved by utilizing the unique spectroscopic properties of lanthanide ions.

The lanthanide metal (europium or terbium) was added to a coumarin-glycine chemodosimeter in a DMSO solvent system. The sensor was titrated with several monodentate analytes including, nitrate, octylamine, 1-pentanethiol, …

A Method For The Determination Of Purity Of Pnu-10483 Bulk Drug By Capillary Zone Electrophoresis, Gavin Gibson

Honors Theses

In this investigation, a method was developed for the determination of purity of the drug PNU-10483 using the technique of capillary zone electrophoresis (CZE). CZE was seen as a potential alternative to the formerly used procedure of ion-pair reversed phase highperformance liquid chromatography (HPLC). Nearly five years earlier, a similar study was performed, in which an attempt was made to develop a method that used CZE to determine the purity of bulk drug and the potency of drug tablets. While this development was mostly successful, sporadically unpredictable results reduced the method's overall viability. These outliers were thought to be caused …

Effect Of Trace Metals On Growth Rate Of Algae, Gabriel H. Srouji

Honors Theses

Heavy metals, although only in traces, are essential for all forms of life. They are taken up by the living cell in the form of cations, and their uptake is strictly regulated because most or all of them are toxic in excess. A remarkable specificity has been found: seldom can an excess of one essential metal prevent the damage caused by deficiency of another. In fact, such an excess often increase the injurious effect of deficiency.

Metal-binding substances, many of which function by chelation, form a class of substances which have furnished many useful drugs and other substances of value …