Physical Sciences and Mathematics Commons^™

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 …

The Concentration Of Heavy Metals In Lincoln Nebraska's Tap Water, Evan Neuhaus

Honors Theses

Heavy metals are commonplace in nature, and are typically found in scarce quantities in all drinking sources. However, in high enough concentrations, they can have a myriad of negative health effects. This study seeks to find the concentrations of such metals in the Lincoln water supply utilizing the resources of the Water Center at the University of Nebraska at Lincoln. To test for discrete concentrations of trace elements, a method of using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was implemented. ICP-MS uses plasma to ionize and atomize a sample which is then filtered into a series of cones into a …

Applications Of Sodium Azide In The Synthesis Of Tetrazines And Hydrolysis Reactions, My Le

Honors Theses

The inverse electron demand Diels−Alder cycloadditions of heterocyclic azadienes have provided a robust methodology for synthesizing highly substituted and functionalized heterocycles. It is widely used in organic synthesis and the pharmaceutical industry in the divergent construction of screening libraries and bioorthogonal conjugation. Each heterocyclic azadiene was found to possess a unique reactivity toward different classes of dienophiles, display predictable modes of cycloaddition, and exhibit substantial substituent electronic effects impacting their intrinsic reactivity and cycloaddition regioselectivity. Synthesis of 1,2,4,5-tetrazine has been reported in the literature since the late 19th century, showing scientists' tremendous interest in its application.

Herein we attempt to …

Synthesis Of A Dd-Π-Aa Organic Dye For Dye-Sensitized Solar Cells, Hope Lovell

Honors Theses

This project investigates the synthesis of a DD-π-AA (dual donor/dual acceptor) organic dye as a potential sensitizer for dye-sensitized solar cells (DSCs). The design of this dye was based off previous research that found dual donor/dual acceptor dyes exhibited promising results when used in a DSC. The donor groups, acceptor groups, and π-bridge were chosen for their stability, ability to absorb in the near-infrared (NIR) region, and intramolecular charge transfer (ICT) abilities.

While many components of the dye were synthesized, the final stages of the synthetic scheme were not completed due to the loss of time from COVID-19. Had the …

Synthesis And Conductivity Analysis Of A Methyl (Polyethylene Glycol) Comb Polymer, Olivia Fox

Honors Theses

The overall goal of work in this field is to improve materials for use in a variety of applications in fuel cell and battery production. This thesis specifically investigates the synthesis of two variations of a methyl (polyethylene glycol) comb polymer electrolyte (MePEG_nwhere n=7) to understand how the molecular structure of an ion-conducting polymer affects its electrochemical properties. The MePEG used in this synthesis contains seven ethylene glycol groups and was added to a poly (methylhydrosiloxane) comb polymer backbone. In the first sample, the polymer contained only the MePEG sidechain, and in the second sample, the polymer contained …

Indolizine Donor-Based Dyes For Applications In Fluorescence Biological Imaging, William Meador

Honors Theses

NIR emissive fluorophores are intensely researched due to their potential to replace modern imaging procedures. Many molecular strategies have been employed in the literature to optimize fluorophores for deeper NIR absorption and emission, biocompatibility, and higher fluorescence quantum yields. Amongst the fluorophores studied to date, proaromatic indolizine donors are attractive alternatives to traditional alkyl amine and indoline based donors due to their 1) lower energy absorption and emission facilitated by proaromaticity, 2) large Stokes shifts due to increased dihedral angles about the π-system, 3) ease of functionalization and capacity for bioconjugation at the phenyl ring, and 4) potential for further …

Approaches Towards The Synthesis Of Ketamine Metabolites, Ann K. Patrick

Honors Theses

Major Depressive disorder (MDD) plagues society and stands at the forefront of research as MDD affects approximately 16% of the population. Pharmaceutical drugs, including the selective serotonin reuptake inhibitors (SSRIs), have been used for MDD treatment and remain a popular option today. However, current antidepressant treatments have proven to be ineffective in just less than half of the patients. Research continues with the goal to better understand the mechanisms of the pathology of depression and to search for other treatment options. For example, the stress-neurogenesis hypothesis investigates the role of stress and decreased neuroplasticity within MDD.

Supporting the stress-neurogenesis hypothesis, …

An Investigation Into The History, Science, And Future Of Dental Filling Materials, Natalia Kaczor

Honors Theses

No abstract provided.

Synthesis And Evaluation Of Nebraska Red Derivatives For Protein Labeling Studies, Lauren Lesiak

Honors Theses

G protein-coupled receptors (GPCRs) play a vital role in cell signaling, and imaging the internalization of these proteins will allow for better understand of protein trafficking within the cell, as well as identification of potential drug targets. However, there is a need for further development of fluorescent protein labels that are able to effectively monitor GPCR internalization in the near-infrared (NIR) range. We recently described a series of NIR fluorophores in which a phosphinate functionality is inserted at the bridging position of the xanthene scaffold, called the Nebraska Red (NR) dye series. These dyes are attractive reagents for the imaging …

Tying The Knot: Applications Of Topology To Chemistry, Tarini S. Hardikar

Honors Theses

Chirality (or handedness) is the property that a structure is “different” from its mirror image. Topology can be used to provide a rigorous framework for the notion of chirality. This project examines various types of chirality and discusses tools to detect chirality in graphs and knots. Notable theorems that are discussed in this work include ones that identify chirality using properties of link polynomials (HOMFLY polynomials), rigid vertex graphs, and knot linking numbers. Various other issues of chirality are explored, and some specially unique structures are discussed. This paper is borne out of reading Dr. Erica Flapan’s book, When Topology …

Progress Towards An Aza-Michael Addition To Ketones, Bowman Potter

Honors Theses

The aza-Michael addition to unsaturated ketones under neutral to mildly basic condition is a difficult transformation due to the inherent unreactivity of ketones toward the addition of weak nucleophiles. This thesis reports on efforts to develop an environmentally friendly, stereoselective and low-cost organo-catalyzed aza-Michael reaction between unsaturated ketones and nitrogen nucleophiles, such as phthalimide, under neutral to mildly basic conditions using the most inexpensive chiral secondary amine catalyst, proline.1 Both proline and the organic base triethylamine were found to be catalytic in the testing platform of cyclohexen-2-one and phthalimide, and another testing platform of 4-hexen-3-one and phthalimide. Likewise, when screened …