Chemistry Commons^™

Fused Arenes-Based Molecular And Polymeric Materials For Organic Field Effect Transistors, Harista Irugulapati

Masters Theses & Specialist Projects

In the past decade, tremendous progress has been made in organic field effect
transistors. Fused oligothiophenes and anthracene molecules are fascinating
macromolecules having unique optoelectronic properties. These compounds are successfully employed as active components in optoelectronic devices including field effect transistors. Our goal is to design and synthesize conjugated molecular materials, which are highly functionalized through structural modifications in order to enhance their electronic, photonic, and morphological properties. The main desire is to synthesize novel organic fused-arenes having efficient charge carrier mobilities, as well as to optimize optical properties for organic field effect transistors (OFETs). Novel series of fused arene …

Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo

Senior Honors Projects

Hexachlorocyclohexanes (HCHs) are a family of chlorinated organic compounds that were previously used as agricultural insecticides. HCHs are recognized as persistent organic pollutants due to their toxicity, recalcitrant properties, and tendency to bioaccumulate in food webs. Although HCH was first synthesized in 1825, its use was not widespread until the discovery of the insecticidal activity of the γ-HCH isomer in 1942. γ-HCH and its toxic waste isomers α-HCH and β-HCH were banned from production and use by the United Nations in 2009, yet these chemicals still present environmental problems due to their persistence in soils and surface waters. HCHs continue …

Pd-­Catalyzed N-­Arylation Of Amides: Catalyst Development And Scope, Tara Brenner

Renée Crown University Honors Thesis Projects - All

Recent development toward more efficient palladium catalyzed amidation reactions has been driven by mechanistic studies and the development of more efficient ancillary phosphine ligands. This review discusses these developments with regard to substrate scope and the nature of the corresponding catalyst systems. Emphasis will be placed on applications of palladium catalyzed amidation reactions and the synthetic utility of these methods.

Interaction Between Lubricants Containing Phosphate Ester Additives And Stainless Steels, David W. Johnson, Matthew Bachus, John E. Hils

Chemistry Faculty Publications

One way to improve fuel efficiency in today’s jet aircraft engines is to create an environment for higher operating temperatures and speeds. New and improved lubricants and bearing materials must be developed to remain stable in these elevated operating temperatures. Three lubricants, with varying amounts of tricresyl phosphate added as an anti-wear/extreme pressure additive were tested on two different stainless steels at varying temperatures ranging from 300 °C to 350 °C in vacuum. Significant decomposition of the lubricant base-stocks and the phosphate ester additive did occur in most of the trials resulting in the formation of carboxylic acids and phenols. …

Strategic Electronic Property Control Of Self-Assembling Pyrazine-Acenes, Lacie Brownell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Control of electronic properties in organic semiconductor materials is essential for electro-optical applications such as field-effect transistors, light-emitting diodes, and photovoltaic devices. This work is focused on two systems that highlight different approaches for the manipulation of electronic properties: (I) the development of electron-deficient (n-type) materials by selective lowering of E_LUMO and (II) low energy gap materials by controlling both E_LUMO and E_HOMO

To specifically lower E_LUMO, a pyrazine-acene π-platform was extended using electron-withdrawing moieties. These include: pyridine, pyrazine, and benzothiadiazole (system I). From the base pyrazine-acene, the most significant change in E_LUMO of …

Experimenting With Polymer Blend Solar Cells And Active Layer Thickness, Ryan Blumenthal

Physics

Bulk heterojunction organic photovoltaics utilize the electrical characteristics of semi-conductive polymers. These solution processable materials are beneficial because of their low material cost, light weight, and simple fabrication requirements. Our devices employ multiple photoactive polymers, P3HT and PCPDTBT, to absorb photons over a wide spectral range. We optimized various device characteristics including thickness and thermal anneal usage to reach a power conversion efficiency of 3.0% in AM1.5 sunlight. Device performance degrades over time due to atmospheric water and oxygen, prompting us to investigate device packaging to extend cell lifetime for additional testing.

Further Studies On The Allylic Diazene Rearrangement, Maha Laxmi Shrestha

Graduate Theses and Dissertations

Former graduate student Wei Qi and Professor Matt McIntosh have reported diastereoselective reductive 1,3-transpositions of acyclic alpha, beta-unsaturated tosyl hydrazones to afford substrates with a 1,4-syn or 1,4-anti relationship between alkoxy and methyl groups that proceed via an ADR (Qi, W.; McIntosh, M. C. Org. Lett. 2008, 10, 357; Qi, W.; McIntosh, M. C. Tetrahedron 2008, 64, 7021). In these reports, silica gel was employed to accelerate the reduction. We have found that acetic acid gives the same results with high diastereoselectivity in the reaction. We further optimized the reaction by lowering the amount of catecholborane to 3 eq. Effects …

Structural And Functional Characterization Of The Ldp3 (Vhz) Protein Tyrosine Phosphatase, Vyacheslav I. Kuznetsov

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein phosphorylation is as an important regulatory mechanism that controls a large number of physiologically important cellular processes. Proteins are phosphorylated on aliphatic (serine and threonine) as well aromatic (histidine and tyrosine) residues predominantly located on sterically accessible loops. Phosphorylation affects three- dimensional structures of proteins resulting in conformational changes which activate or deactivate enzymatic functions. Because of the ability of protein phosphorylation to modulate a multitude of diverse cellular processes, it became an appealing and promising target for drug therapy.

Attachment of phosphate is accomplished by kinases, whereas the removal of the phosphoryl group is performed by protein phosphatases. …

Molecularly Woven Materials From Metal-Organic Precursors, Gellert Mezei, Jaafar Hachem, Isurika R. Fernando, Natasha R. Wadhwa, Neil C. Hughes

Faculty Research and Creative Activities Award (FRACAA)

No abstract provided.

Electron Transfer In Electrophilic Aromatic Nitration And Nitrosation, Yirong Mo, Zhenhua Chen

Faculty Research and Creative Activities Award (FRACAA)

No abstract provided.

Facile Synthesis Of Silver Nanoparticles Stabilized By Cationic Polynorbornenes And Their Catalytic Activity In 4-Nitrophenol Reduction, Bharat Baruah, Gregory J. Gabriel, Michelle J. Akbashev, Matthew E. Booher

Faculty Articles

We report the facile one-pot single-phase syntheses of silver nanoparticles stabilized by norbornene type cationic polymers. Silver nanoparticles (AgNPs) stabilized by polyguanidino oxanorbornenes (PG) at 5 and 25 kDa and polyamino oxanorbornenes (PA) at 3 and 15 kDa have been synthesized by the reduction of silver ions with NaBH4 in aqueous solutions at ambient temperature. The four different silver nanoparticles have been characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and transmission electron microscopy (TEM) for their particle size distributions. Interestingly, PG stabilizes the silver nanoparticles better than PA as evident from our spectroscopic data. …

Metal-Organic And Supramolecular Architectures Based On Mechanically Interlocked Molecules, Isurika Rosini Fernando

Dissertations

The focus of this work is on mechanically interlocked molecules (MIMs), which have unusual physicochemical and mechanical properties with potential applications in nano-scale/molecular devices and high strength materials.

Rotaxanes, for example, consist of an axle-like molecule threaded through a wheel-like molecule, with bulky groups at the two ends of the axle preventing the wheel from dissociating. The position of the wheel along the axle can be switched in a controllable and reversible manner by applying external stimuli, a feature that might lead to the next generation of computers. Molecularly woven materials (MWMs), another example of molecules with mechanically interlocked features, …

Expulsion Of Leaving Groups From Zwitterionic Intermediates Generated Via Photochemical Electrocyclic Ring Closure Reactions And An Investigation On Tpe Oligomers, Tasnuva Shahrin

Dissertations (1934 -)

Photochemical cleavage reactions have been found widespread use in biological applications that require intracellular photochemical release of biologically active substrates such as peptides, proteins, neurotransmitters, or nucleotide phosphates. The research is to devise photoremovable protecting groups (cage compounds) that can be used to deprotect those biological substrates by irradiation. A number of photocleavage reactions have been developed in recent years which release chlorides, hydroxides, carboxylates, thiolates, and phenolates leaving groups for use in such applications. Nevertheless, photochemical elimination reactions that expel such leaving group anions remain quite uncommon. The cleavage of cage compounds via photolysis requires heterolysis of a bond …

A Novel Algorithm For Validating Peptide Identification From A Shotgun Proteomics Search Engine, Ling Jian, Xinnan Niu, Zhonghang Xia, Parimal Samir, Chiranthani Sumanasekera, Zheng Mu, Jennifer L. Jennings, Kristen L. Hoek, Tara Allos, Leigh M. Howard, Kathryn M. Edwards, P. Anthony Weil, Andrew J. Link

Chemistry Faculty Research

Liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) has revolutionized the proteomics analysis of complexes, cells, and tissues. In a typical proteomic analysis, the tandem mass spectra from a LC–MS/MS experiment are assigned to a peptide by a search engine that compares the experimental MS/MS peptide data to theoretical peptide sequences in a protein database. The peptide spectra matches are then used to infer a list of identified proteins in the original sample. However, the search engines often fail to distinguish between correct and incorrect peptides assignments. In this study, we designed and implemented a novel algorithm called De-Noise to …

Spectral Data For "Generation Of Molecular Complexity From Cyclooctatetraene: Preparation Of Optically Active Protected Aminocycloheptitols And Bicyclo[4.4.1]Undecatriene", Mohamed F. El-Mansy, Anobick Sar, Sergey V. Lindeman, William A. Donaldson

Natural Products Synthesis via Organoiron Methodology

Spectral data created in the course of the research project. Supports specific findings in "Generation of Molecular Complexity from Cyclooctatetraene: Preparation of Optically Active Protected Aminocycloheptitols and Bicyclo[4.4.1]undecatriene".

The racemic (6-cyclo-heptadienyl)Fe(CO)₃⁺ cation ((±)-7), prepared from cyclooctatetraene, was treated with a variety of carbon and heteroatom nucleophiles. Attack took place at the less hindered C¹ dienyl carbon and decomplexation of the (cycloheptadiene)Fe(CO)₃ complexes gave products rich in functionality for further synthetic manipulation. In particular, a seven-step route was developed from racemic (6-styryl-2,4-cycloheptadien-1-yl)phthalimide ((±)-9 d) to afford the optically active aminocycloheptitols (−)-20 and …

Preparation Of Organofluorine Compounds: Exploring Mono-, Di-, And Tri-Fluorination, Diandra M. Rudzinski

Master's Theses

Organofluorine compounds exhibit biological activity and have advantageous properties for drug design. Natural occurring fluorinated molecules are rare, demanding new synthetic methods for their preparation. A novel route to access trifluoromethyl ketones from Weinreb amide precursors is discussed. This is the first documented method for the use of the Ruppert-Prakash reagent, (trifluoromethyl)trimethylsilane, for the production of trifluoromethyl ketones from amide starting materials. This method is tolerant of aryl and alkyl substrates exhibited by their moderate to excellent yields. A discussion of the unusual reactivity of these amides, their selectivity for mono-trifluoromethylation, and other mono-, and di-fluorination attempts are reported.

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR Program Research Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on …

Organic Thin-Film Transistors And Tips-Pentacene, Zachary Stewart

Lewis Honors College Capstone Collection

TIPS-Pentacene, an organic semiconductor characterized by its good electronic properties, solubility, and stability, is used primarily in organic thin-film transistors (OTFT). This research seeks to create an OTFT by crafting a stencil, depositing the source and drain onto a substrate’s surface, and processing TIPS-Pentacene onto the channel between them. In addition, if time permits, the electronic properties of several OTFTs will be compared to determine how to optimize their production.

Synthesis And Application Of Atp Analogs For Phosphorylation-Dependent Kinase-Substrate Crosslinking, Satish Kumar Garre Venkata Raghavendra

Wayne State University Dissertations

Phosphorylation is an important post-translational modification that plays a key role in a variety of signaling cascades and cellular functions. Kinases phosphorylate protein substrates in a highly regulated manner and are promiscuous. Understanding kinase-substrate specificity has been challenging and there is a need for new chemical tools. To this end we developed -phosphate modified ATP photocrosslinking analogs ATP-ArN3 and ATP-BP, that crosslink substrate and kinase in a phosphorylation dependent manner. We have successfully demonstrated that ATP-ArN3 and ATP-BP can be used with natural kinase and substrates using cell lysates in vitro. We used our approach to identify novel kinases of …

1. Chromium(0)- Promoted Higher Order Cycloaddition Reactions: Studies Toward The Total Synthesis Of The Cyclocitrinols And Echinopines A And B 2. Total Synthesis Of (±)-Debromoflustramine B Via [4+1] Cyclization Of An Indole Isocyanate And A Bis(Alkylthio)Carbene, Saptarshi De

Wayne State University Dissertations

A facile and short stereoselective synthesis of the functionalized tetracyclic core structure of the cyclocitrinols, a family of unusual C25 steroid isomers, has been accomplished. The key structural unit, the bicyclo[4.4.1]A/B ring system, was constructed by a regioselective Cr(0)-promoted [6π + 4π] photochemical cycloaddition reaction.

A Bronsted acid catalyzed rearrangement of the 11-trimethylsilyl-tetracyclo[8.1.0.03,7.04,11]undeca-5,8-diene ring system to the unusual homotriquinacene ring system. The trimethylsilyl substitution on the cyclopropane moiety was found to be crucial for the rapid transformation which is believed to proceed via carbocation intermediates.

A short concise formal synthesis of Echinopines A and B is reported. The key [5.5.7] …

Adding Gas Chromatography-Mass Spectrometry Data To A Melting Point And Thin-Layer Chromatography Laboratory, Adam M. Azman, Julie A. Barrett, Megan Darragh, John J. Esteb

Scholarship and Professional Work - LAS

The addition of gas chromatography–mass spectrometry (GC–MS) data interpretation to a thin-layer chromatography (TLC) and melting point (mp) laboratory for an introductory organic course is described.

The Rich Chemistry Of Cyclotriveratrylene (Ctv) And Ct-Inspired Reactions: Anthracenes With Organic Light-Emitting Diode (Oled) Applications And The Discovery Of Cascade Reactions, Samuel Sarsah

Dissertations

Cyclotriveratrylene (CTV) is a supramolecular scaffold with applications in host-guest chemistry, analytical detection, drug delivery and liquid crystals. We have discovered that CTV rearranges to a highly functionalized anthracene derivative that is ideal for the synthesis of 9,10-disubstituted anthracene derivatives that are useful for the construction of organic light-emitting diodes (OLEDs). Several diaryl anthracene derivatives have been synthesized and analyzed, and were found to have excellent electroluminescent properties, including one analog that exhibits an exceptionally high quantum yield. Red, green and blue are the primary colors needed for full color display, but blue fluorescence emitting organic compounds used in OLEDs …

Diffusion Of Vitamin B12 Across A Mesoporous Metal Organic Framework, Veronica Valencia

Undergraduate Journal of Mathematical Modeling: One + Two

We measure the rate of uptake and the rate of release of a Vitamin B12 solution (dissolved in water) at 2 different temperatures (room temperature and 37°C) by the mesoporous metal organic framework TbMOF-100 at 1-hour intervals using a spectrophotometer. Using the Beer-Lambert law, we calculate the concentration of the stock solution based on the absorbance values obtained with the spectrophotometer. These values allow for the quantification of the initial rate of uptake and the rate of uptake at a random incubation time of the Vitamin B12 by the TbMOF-100. We also calculate the value of the coefficient of diffusion …

Preparation Of Phosphonoterephthalic Acids Via Palladium-Catalyzed Coupling Of Aromatic Iodoesters, Nathaniel Ivan, Vladimir Benin, Alexander Morgan

Chemistry Faculty Publications

The current article reports in detail the preparation of two phosphonoterephthalic acids: 2-phosphonoterephthalic acid (1) and 2,5-diphosphonoterephthalic acid (2). Efficient, scalable syntheses have been developed for both compounds based on Pd-catalyzed coupling reactions of iodinated terephthalate esters. Phosphonoterephthalic acids are potentially useful as flame-retardant additives or as monomers for the construction of acid-pendant polymer chains.

Synthesis Of Orthogonally Protected Azalanthionines (Lanazanines) By Sequential Ring-Opening Of N-Substituted Aziridine 2-Carboxylates, Keith O'Brien, Keith Ó Proinsias, Fintan Kelleher

Articles

Orthogonally protected azalanthionines (lanazanines, 4-azadiaminopimelic acids or b-aminoalaninoalanines) have been synthesised in good yields by the ring-opening of N-protected aziridine 2-carboxylates with suitably protected diaminopropanoic acids (DAPs). The required DAPs were also synthesised by ring-opening of N-protected aziridine 2-carboxylates with para-methoxybenzylamine.

Study On Polydimethylsiloxane (Pdms) Surface Over The Time, Saeed A. Bigdeli

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Synthetic Approaches To Thiacorannulene, Rama Yaghi

Legacy Theses & Dissertations (2009 - 2024)

Thiacorannulene is an unknown, open geodesic heteropolyarene comprised of a central five-membered ring surrounded by four benzene rings and one thiophene ring. This heterobuckybowl is expected to have unique physical, chemical and biological properties. The curvature in thiacorannulene should provide two distinct surfaces, convex and concave, and should affect properties such as dipole moment, ionization potential, metal binding, etc. Having a thiophene ring embedded in its structure is expected to influence the reactivity of this compound. We sought to devise syntheses of the unknown heterobuckybowl based on earlier, optimized syntheses of buckybowls, heterobuckybowls, and heterocirculenes. Details of our attempted syntheses …

(S)-Trifluoroselenomethionine : A New Non-Natural Amino Acid With Enhanced Methioninase-Induced Cytotoxicity Toward Human Colon Cancer Cells, Stephene Nathele Lodge

Legacy Theses & Dissertations (2009 - 2024)

Abstract

Iron (Iii) Tosylate Catalyzed Synthesis Of 3,4-Dihydropyrimidin-2(1h)-Ones/Thiones, Ram Mohan, Jacob Starcevich, Thomas Laughlin

Scholarship

No abstract provided.

Amalgamation Of Nucleosides And Amino Acids In Antibiotic Biosynthesis, Sandra H. Barnard

Theses and Dissertations--Pharmacy

The rapid increase in antibiotic resistance demands the identification of novel antibiotics with novel targets. One potential antibacterial target is the biosynthesis of peptidoglycan cell wall, which is both ubiquitous and necessary for bacterial survival. Both the caprazamycin-related compounds A-90289 and muraminomicin, as well as the capuramycin-related compounds A-503083 and A-102395 are potent inhibitors of the translocase I enzyme, one of the key enzymes required for cell wall biosynthesis. The caprazamycin-related compounds contain a core nonproteinogen b-hydroxy-a-amino acid referred to as 5’-C-glycyluridine (GlyU). Residing within the biosynthetic gene clusters of the aforementioned compounds is a shared open reading …