Organic Chemistry Commons^™

Steric And Electronic Considerations Of Ester Hydrolysis: Updating A Longstanding Physical Organic Kinetics Experiment, Mara J. Aucoin

Chemistry Theses

A current, longstanding undergraduate physical chemistry kinetics experiment uses UV-Vis spectrophotometry to follow the hydrolysis of para-nitrophenyl acetate (NPA) with an imidazole (Im) catalyst. The catalyzed and uncatalyzed reaction paths can be studied simultaneously under pseudo first order conditions ([Im]>>>[NPA]). To obtain the rate constants for the catalyzed and uncatalyzed reactions, the concentration of imidazole is varied between reactions and then plotted against the observed rate constant (k_obs).This produces a linear line where the slope is equal to the rate constant of the catalyzed reaction (k_cat) and the intercept is equal to …

Synthesis Of Piperidine Heterocycles With Specific Functional Groups Via Sn2 Reactions, Teyanna Monroe

Honors Theses

Piperidine is a heavily utilized nitrogen containing heterocycle found in numerous pharmaceutical agents, solidifying its importance as a building block in drug development. The focus of this research is to investigate different mechanisms of action for adding and replacing various functional groups utilizing readily available lab materials. These findings would lead to determining the overall influence of substitution patterns and functional groups have on stereochemistry, reactivity, and overall conformation of the piperidine ring. The synthetic approach involves the formation of 3-bromo-5-methoxy-tosylpiperidine intermediate through acid promoted cyclization, followed by nucleophilic substitution reactions to introduce various functional groups. Reaction progress and product …

Crystallization And Utility Of Brominated Phenylethynylene Bis-Urea Macrocycles, Paras Srivastava

Senior Theses

Macrocycles are large, cyclic molecules with central cavities that can encapsulate other molecules and that have uses in supramolecular chemistry. The Shimizu group has previously synthesized Macrocycle 1, a phenylethynylene bis-urea macrocycle that crystallizes in a columnar form, enabling its utility as a host in host-guest systems. Reactions within these systems can be used to modify stereospecificity, kinetics, and other physical properties. Previously, photodimerization reactions between coumarins and chromones have been studied in systems of Macrocycle 1, resulting in the improved specificity of photodimerization products. Herein, we apply a dynamic covalent chemistry (DCC) strategy to synthesize Macrocycle 1 and its …

Increased Backbone Rigidity Of Artificial Transcription Factors, Jasmine Glover, Emma Otey, Joanna K. Kwao, Nicholas Truex

Senior Theses

Programming DNA-binding proteins is an effective strategy for developing therapeutics that regulate gene expression. These proteins can directly bind to DNA to activate or repress transcription of specific genes. Zinc finger proteins are a class of DNA-binding proteins commonly found in eukaryotic organisms. Their DNA-binding function is derived from unique amino acid sequences within each domain that recognizes specific nucleotides, allowing each finger to selectively recognize three DNA base pairs. Adjoining of multiple domains in tandem allows recognition of a specific DNA sequence. Artificial transcription factors can be made of multiple zinc finger domains arranged in tandem and engineered to …

Design And In Silico Modeling Of Heterocyclic-Based Xanthone Derivatives As Potential Anticancer Agents Through Tyrosine Kinase Inhibition, Yehezkiel Steven Kurniawan, Ervan Yudha, Nela Fatmasari, Radite Yogaswara, Harno Dwi Pranowo, Eti Nurwening Sholikhah, Jumina Jumina

Makara Journal of Science

Cancer is one of the deadliest diseases nowadays, and tyrosine kinase receptors play crucial roles in cancer cell survival, differentiation, proliferation, and migration. This study designed and developed a new inhibitor from heterocyclic-based xanthone derivatives to target two tyrosine kinase receptors, epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor (PDGFR), through in silico screening. Eighteen heterocyclic-based xanthones were evaluated through molecular docking for both receptors. All heterocyclic-based xanthones gave the root mean square deviation (RMSD) value lower than 2.00 Å. Xanthone with isobenzothiazole substituent (iBzThio) was found as the most potent inhibitor with binding energies of -10.60 and …

Top-View Method As A Robust Alternative For Contact Angle Measurement, Bi-Min Zhang Newby, Emmanuel Agyei

University Research

This study validates the top-view method for contact angle measurement, based on the spherical cap assumption, as a practical alternative to conventional side-view techniques. It is particularly useful when side-view imaging is challenging, such as on rough, deformable, irregular, or confined areas where baseline visibility, meridian clarity, or drop symmetry is compromised. To address these challenges, this study details the simultaneous acquisition of top and side-view images of sessile drops along with precise drop volume via drop mass measurements. The contact angles were then deduced from drop volume and contact area based on the spherical cap assumption. Contact angles of …

Physical And Chemical Study Of Interaction In The Urea–Valine System For The Creation Of Modified Liquid Nitrogen Fertilizers, Suvonkul Erkhanovich Nurmonov, Saydullo Khamidovich Azimov

Chemical Technology, Control and Management

This study reports the results of a comprehensive physicochemical investigation of the urea–L-valine binary system, conducted to validate its potential as a modified base for liquid nitrogen fertilizers.

By utilizing the methods of isomolar series, visual-polythermal analysis, X-ray phase (XRD) and single-crystal X-ray diffraction (SC-XRD), synchronous thermal analysis (TGA/DTA), and FT-IR spectroscopy, it was determined that the interaction between components in both aqueous solutions and the solid phase results in the formation of molecular associates stabilized by hydrogen bonds, without the formation of new stoichiometric compounds.

The concentration and temperature limits of the system's stability were defined, revealing a reduction …

An Undergraduate Chemistry Experiment Integrating Theoretical And Practical Aspects Of Hypervalent Iodine(I) Compounds, Vladimir L. Kolesnichenko, Galina Z. Goloverda

Faculty and Staff Publications

A simple reaction sequence has been developed to produce iodine chloride-pyridine (PyICl) and pyridinium dichloroiodate (PyHICl2), convenient iodinating agents, in a high yield. Our approach is safe and simple to handle, avoiding the use of elemental chlorine or hazardous manipulations. Designed for an upper-level undergraduate hybrid lecture/lab chemistry course, the experiment integrates key concepts from both inorganic and organic chemistry. The pre-experiment lecture explains the connections between molecular structure, reactivity trends, and reaction types. Over three 4 h lab sessions, students carry out a sequence of quantitative transformations and characterize each intermediate and the final product using ESI mass spectrometry, …

Development Of Novel Anti-Cancer Colchicine Analogs: Synthesis And Configurational Studies, Orugbani S. Eli

Dissertations, Theses, and Capstone Projects

Colchicine, a naturally occurring alkaloid, has long been known as a potent therapeutic agent. Despite its efficacy treating gout and other inflammatory disorders, its severe toxicity, limited selectivity, and poor pharmacological profile have restricted its broader clinical application. Reported advantages of colchicine-site ligands as vascular-disrupting agents, including reduced susceptibility to multidrug resistance, have revived interest in the colchicine site on tubulin as a validated therapeutic target for cancer. This dissertation focuses on the development of new colchicine analogs, detailing the synthetic method to functionalized AC-ring derivatives, as well as the evaluation of their configurational stability and biological activity.

In Chapter …

Monosaccharide Binding To Synthetic Carbohydrate Receptor Microarrays, Milan A. Shlain

Dissertations, Theses, and Capstone Projects

Chapter 1: A glycan detection platform comprised of synthetic carbohydrate receptors (SCRs) immobilized onto polymer brushes was prepared. SCR043, an alkene-containing SCR, was incorporated into grafted-from polymer brushes using hypersurface photolithography, resulting in microarrays of SCR043-functionalized polymer brushes, where brush height (h) and SCR grafting density (Γ) is controlled precisely at each feature in the array. The influence of h and Γ on the binding to five fluorescently labelled monosaccharides – α-glucose (α-Gluc-FL), α-galactose (α-Gal-FL), α-mannose (α-Man-FL), β-glucose (β-Gluc-FL), and β-galactose (β-Gal-FL) – in aqueous buffer …

Interview With Orca Award Winner Reuben Rieke, Unl Chemistry; Discoverer Of Rieke Metals, Mark Griep, Reuben Rieke

UNL ORCA Interview Series

Emeritus Prof. Reuben Rieke was awarded the ORCA in 1995. Reuben was born in Fairfax, Minnesota. Something in his youth must have sparked an interest in science because he traveled 100 miles east to The University of Minnesota where he earned a bachelor’s in chemistry. Next, he earned a doctorate from the University of Wisconsin, and did postdoctoral work at the University of California Los Angeles. In 1977, after about 11 years as a faculty member in the chemistry department at the University of North Carolina, he joined UNL as a full professor of chemistry. I’ll share two remarkable facts …

Monomeric And Dimeric Metal Complexes Of A New Tridentate Azole-Isoindoline-Urea Ligand, Ben Hudak

Williams Honors College, Honors Research Projects

1,3-Diiminoisoindoline (DII) compounds have been found to be novel materials for both metal binding and chromophore applications. In this work, I am investigating the next synthetic step in developing pyrazole- and indazole-DII compounds. These compounds stem from the reaction of the unsubstituted imine of the pyrazole- or indazole-DII adduct with an isocyanate. These DII compounds, DII-pyrazolePhNCO, DII-pyrazolenapthylNCO, DII-indazolePhNCO, DII-indazolenapthylNCO, DII-pyrazoleptolylNCO, and DII-indazoleptolylNCO were prepared using ethanol as the solvent and heat. Metal acetates were then reacted with the ligands using DMF and heat. The acetate salts included copper (II) and nickel(II). Some distinctive hydrogen bonding interactions were observed in the …

Using Nmr Spectroscopy And Linear Discriminant Analysis To Molecular Profile Varietal Honey, Taylor Mac

Master's Theses and Doctoral Dissertations

In recent years, varietal honey has been a massive target of adulteration through mislabeling and the addition of other sugars. Unethical companies do this to cut production costs while still charging the consumer full price. Previous studies have used nuclear magnetic resonance (NMR) to unravel possible adulteration in honey, but currently, there are no standard rapid methods to authenticate varietal honey. In our research, we collected NMR signatures (“fingerprints”) and combined them with linear discriminant analysis (LDA) to predict the varietal, country, and region of varietal honey. As a part of the project, we investigated whether an adjustment to the …

Scalable Transfer Of Dna Origami–Directed Nanoparticle Arrays Onto Functional Surfaces Using Thermal Release Tape, Yuwei Zhang, Chikadibia Genevieve Edward, Ethan Keuhn, Shelley D. Minteer, Risheng Wang

Chemistry Faculty Research & Creative Works

Precise integration of DNA origami nanostructures onto functional substrates is essential for advancing electronics, photonics, and biosensing. However, most surface-assembly methods are highly sensitive to substrate type, limiting their broader applications. Here, we introduce a thermal release tape (TRT)-assisted transfer method that enables efficient, large-area printing of DNA origami-guided gold nanoparticle (AuNP-DNA origami) arrays from mica onto diverse surfaces. The method relies on differential adhesion: AuNP-DNA origami arrays form strong electrostatic and hydrogen-bonding interactions with 3-aminopropyltriethoxysilane (APTES)-functionalized receiver substrates, while the TRT adhesive weakens upon heating to 120°C, allowing release from the tape. Using this approach, well-ordered AuNP-DNA origami arrays …

Design, Synthesis, And Characterization Of Phosphonate-Functionalized Diimide Ligands For Metal-Organic Framework Construction, Kenya Rosas, Jonathan Uribe

Posters - 2026

• Metal–organic frameworks (MOFs) are solid, porous materials composed of metalions reacted with organic linkers

• MOFs are customizable through variations in their metal ions, organic linkers, and the functional groups of the organic linker all yielding a structure with different properties

• MOFs have a variety of applications, ranging from storage and catalysis to drug delivery

• The synthesis and characterization of four phosphonate-based diimide ligands:
  • N,N´-bis(phosphonomethyl)-pyromellitimide (PPMI).
  • N,N´-bis(phosphonobenzyl)-pyromellitimide (PPMI-Ph).
  • N,N´-bis(phosphonomethyl)-3,3′,4,4′-biphenylenediimide (PBDI).
  • N,N´-bis(phosphonobenzyl)-3,3′,4,4′-biphenylenediimide (PBDI-Ph).

• These ligands were then coordinated with zinc or copper metal ions to make MOFs.

Investigating The Role Of Humic Acid In The Adsorption Mechanics Of Acetaminophen On Potassium Persulfate-Aged Polyethylene Terephthalate (Pet), Andrew Littleton, Maria Danielle Garrett, Phd

SPARK Symposium Presentations

Pharmaceutical contaminants such as acetaminophen (APAP) are showing a rising presence in aquatic environments, where their interactions with microplastics (MPs) can potentially modulate natural degradation mechanisms. Concurrent presence of the two substances has been shown to potentiate increase their individual harmful effects. This study investigates whether oxidative aging and humic-acid surface modification of PET microplastics influence APAP adsorption.

In this study, UV-aging was reproduced using an iron (II)-activated potassium persulfate (Fe(II)-KPS) oxidation system. Aqueous dissolved organic matter (DOM) is simulated using multi-hour exposure to humic acid. The MPs are then removed from the solution to examine adsorption mechanisms. While most …

Exploring The Limitations Of Substrate Scope In Dimethylallyltryptophan Synthases, Evan T. Miller

Theses and Dissertations--Pharmacy

Natural products (NPs), are the largest source of bioactive compounds in Nature, and are essential to the treatment of human disease. Nearly 50% of drugs approved for use from 1981 to 2019 owe some aspect of their development to NPs, either in terms of their structure, pharmacophore, or mechanism of action. However, NPs are difficult to structurally optimize. Chemoenzymatic methods for NP derivatization have been increasingly seen as practical alternatives to traditional synthetic methods. Prenyltransferases (PTs) are involved in the primary and secondary metabolism of plants, bacteria, and fungi, and they are key enzymes in the biosynthesis of many clinically …

Photo And Spatial Control Of Rna Structures And Functions: Exploring Positional Effects And Photo-Responsiveness Of Azobenzene Modified Nucleotides, Jinxi Du

Electronic Theses & Dissertations (2024 - present)

RNA molecules perform many important biological functions by forming complex three-dimensional structures stabilized by base pairing, tertiary interactions, and metal ion coordination. Because RNA function depends strongly on its structure, methods that allow reversible control of RNA conformation and activity are important for understanding RNA behavior and for potential therapeutic applications. However, achieving reversible and site-specific control of RNA structure, especially at the single-nucleotide level, remains challenging. In this dissertation, I developed and applied azobenzene-modified nucleotides as a chemical tool to enable optical and spatial control of RNA structure and function.

The first part of this dissertation focuses on establishing …

Investigations Toward A Unified Reaction Pathway Of Thermal And Tbsotf-Mediated Oxidopyrylium-Alkene (5 + 2) Cycloadditions, Adam J. Youman, Samantha N. Rokey, Wentao Guo, Jacob P. Grabowski, Susanna N. Angles, Jacob J. Bulandr, Qing Sun, John R. Goodell, Dean J. Tantillo, T. Andrew Mitchell

Faculty Publications – Chemistry

Oxidopyrylium-based (5 + 2) cycloadditions are crucial reactions to construct seven-membered carbocycles containing an ether bridge (i.e. oxabicyclo[3.2.1]octanes). Intramolecular silyloxypyrone-based (5 + 2) cycloadditions were investigated and revealed several features: (1) the TBDPS thermal process proceeds via a zwitterionic oxidopyrylium intermediate similar to previously reported TBS variants; (2) the TBSOTf-mediated reaction proceeds through a cationic oxidopyrylium intermediate; (3) quantum chemical calculations predict a stepwise process for an electron-rich dipolarophile for each set of conditions. The thermal silyloxypyrone-based (5 + 2) cycloadditions were extremely dependent on the nature of the dipolarophile and the silyl transfer group. The TBDPS enhances the …

Net Carbonyl Ene Reactions Of Olefins With Aldehydes, Alexandra Mock

Honors Theses

Aldehydes and olefins react in the presence of base and TMSOTf to yield homoallylic alcohols. In this net ene reaction, TMSOTf acts as a Lewis acid to activate the aldehyde, leading to a strong oxygen-silicon bond that acts as a driving force in the reaction. In the proposed mechanism, the α-methylstyrene attacks the carbonyl carbon of the TMSOTf-activated aldehyde to produce a carbocationic intermediate. Elimination using a relatively bulky base (2,6-lutidine) provides the homoallylic alcohol. This reaction has proven robust in terms of the aldehyde and olefin scope.