Chemistry Commons^™

High Resolution Intracavity Laser Absorption Spectroscopy Of Transition Metal-Containing Diatomic Molecules, Kristin Bales

Dissertations

Three transition metal-containing diatomic molecules have been studied using intracavity laser spectroscopy. Many of the transitions were recorded using a Fourier-transform spectrometer for detection, allowing collection at Doppler-limited resolution for the gas phase molecules. Several vibrational bands in two electronic transition systems of tantalum fluoride (TaF) have been analyzed, and new molecular constants provided. Transitions involving six electronic states of tungsten sulfide (WS) have been analyzed, with new and updated constants provided, including a deperturbation analysis of three vibrational bands in two of the states. Finally, a fresh perspective on two electronic states of tungsten oxide (WO) included a deperturbation …

Degradation Of Oligo[Poly(Ethylene Glycol) Fumarate] Hydrogels Through Stimulus-Mediated Pendent Group Cyclization, Andrew Chung, Burak Tavsanli, Elizabeth Gillies

Chemistry Publications

Hydrogels are of interest for a wide range of applications including drug delivery, regenerative medicine, agriculture, and personal care products. Among the water-soluble synthetic polymers that can be processed to form hydrogels, oligo[poly(ethylene glycol) fumarate] (OPF) has attracted significant attention. The degradation of OPF can be tuned to some extent based on the poly(ethylene glycol) chain length and amount of cross-linker incorporated, but the degradation is generally quite slow, occurring over several months. Here we introduce a new approach to tune and trigger the degradation of OPF. Fumarate alkenes were functionalized to introduce protected pendent amines, that after deprotection could …

New Chemical Dopant And Counterion Mechanism For Organic Electrochemical Transistors And Organic Mixed Ionic–Electronic Conductors, Vianna N. Le, Joel H. Bombile, Gehan S. Rupasinghe, Kyle N. Baustert, Ruipeng Li, Iuliana P. Maria, Maryam Shahi, Paula Alacon Espejo, Iain Mcculloch, Kenneth R. Graham, Chad Risko, Alexandra F. Paterson

Chemistry Faculty Publications

Organic mixed ionic–electronic conductors (OMIECs) have varied performance requirements across a diverse application space. Chemically doping the OMIEC can be a simple, low-cost approach for adapting performance metrics. However, complex challenges, such as identifying new dopant materials and elucidating design rules, inhibit its realization. Here, these challenges are approached by introducing a new n-dopant, tetrabutylammonium hydroxide (TBA-OH), and identifying a new design consideration underpinning its success. TBA-OH behaves as both a chemical n-dopant and morphology additive in donor acceptor co-polymer naphthodithiophene diimide-based polymer, which serves as an electron transporting material in organic electrochemical transistors (OECTs). The combined effects enhance OECT …

Rhodium-Catalyzed Asymmetric Synthesis Of P-P And P-C Bonds, Sarah T. Chachula

Dartmouth College Ph.D Dissertations

Chapter 1: Synthesis, Structure, Dynamics, and Enantioface-Selective η3-Benzyl Coordination in the Chiral Rhodium Complexes Rh(diphos*)(η3-CH2Ph) Abstract: The rhodium benzyl complexes Rh(diphos*)(η3-CH2Ph) (1-14, diphos* = chiral bis(phosphine)) were prepared either by treatment of Rh(COD)(η3-CH2Ph) (15, COD = 1,5-cyclooctadiene) with diphos*, or from the reaction of [Rh(diphos*)(Cl)]2 (16- 20) with PhCH2MgCl. For C2-symmetric diphos*, observation of one set of NMR signals for complexes 1-12 suggested that the two diastereomers in which different 3-benzyl enantiofaces were coordinated to rhodium interconverted rapidly on the NMR time scale via suprafacial shifts; observation of five inequivalent aryl 1H NMR signals showed that antarafacial shifts were slow …

Synthesis Of Tools For The Investigation And Treatment Of Infectious Diseases, Grant Lawrence

USF Tampa Graduate Theses and Dissertations

Modern medicine’s ability to treat a wide array of diseases is due mainly to the development of small-molecule drug discovery. Thousands of years of traditional medicines have been dwarfed in less than a hundred years. In addition, drug discovery has becoming a more consistent process with the introduction of the clinical trials process as well.Plasmodium is a genus of tropical parasites that have the potential to wreak havoc on billions of people globally. Current methods of drug discovery aimed at defeating these parasites require expensive assays that use radioactive material. By using an alkyne-labeled agent instead of a tritium-labeled agent, …

Synthesis Of Small Molecule Modulators Of Non-Traditional Drug Targets, Jamie Nunziata

USF Tampa Graduate Theses and Dissertations

This work details the effort toward structure-activity-relationship (SAR) studies and synthesis of the small molecule modulators of two non-traditional drug targets. The first part of this manuscript (chapters 1–2) will discuss the collaborative work and synthesis of an inhibitor of Slingshot Homology 1 (SSH1) with the potential therapeutic application toward Alzheimer’s Disease (AD) treatment. The second part (chapters 3–6) will discuss the synthetic efforts toward modulation of a protein target known as STING, or stimulator of interferon genes, with the therapeutic application toward autoimmune disease or anti-tumor activity.

AD is a progressive and degenerative illness that holds the title of …

From Waste To Energy: The Electrochemical Reduction Of Co2 Using Recycled Nanostructured Catalysts, Ibrahim Badawy

Theses and Dissertations

The reduction of carbon dioxide (CO₂RR) using electrochemistry is a promising solution for the burgeoning global energy crisis. The overall vision of its implementation relies on renewable energy sources to power the reaction creating carbon neutral products and effectively closing the carbon cycle. Research in this field has come a long way since its inception in the mid-1900s. However, there remain significant hurdles and important considerations to overcome in order to reach full commercialization. Most electrocatalysts tested for CO₂RR have been designed solely for maximum performance while ignoring the environmental consequences if such a material were …

Concurrent Reduction And Stabilization Of Graphene Oxide Dispersion By Silk-Inspired Polymer, Zoren Valmonte, Zeyad Baker, Jianna Loor, Amrita Sarkar

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Silk, a popular biomaterial, is used as a greener alternative of toxic reducing agent in biocompatible graphene synthesis. However, silk often forms gel uncontrollably due to its heavy-chain molecular weight and faces significant challenges in the reduction, stabilization, and dispersion process of graphene. In this contribution, we report a rapid chemical synthesis approach for a low-molecular-weight silk-inspired polymer via ring-opening and microwave-assisted Diels-Alder-aided step-growth polymerizations. This synthetic polymer with periodic sequences of hydrophilic and hydrophobic moieties not only reduces graphene oxide efficiently but also enhances the dispersibility of hydrophobic reduced graphene oxide in aqueous media.

Photophysical Properties Of Synthetic Oligomeric Phenylene Ethynylene, Hugh F. Fritz Jr.

Chemistry and Chemical Biology ETDs

Oligomeric Phenylene Ethynylenes (OPEs) are a class of synthetically prepared compounds with the basic structure of phenylene rings connected by triple-bonded carbon atoms, also known as an ethyne link. This structure can be modified by incorporating functional groups onto one or more of the phenylene rings. The addition of functional groups, such as sulfoxide or imidazole, may alter the photophysical properties in detectable ways. The photophysical techniques used in this report include fluorescence, spectroscopy in the ultraviolet and visible light range (UVVIS), and photon-based excitation using a photo chamber.

One attractive function of OPEs is their antimicrobial property. Previously published …

Elucidating Interprotein Energy Transfer Dynamics Within The Antenna Network From Purple Bacteria, Dihao Wang, Olivia C. Fiebig, Dvir Harris, Hila Toporik, Yi Ji, Chern Chuang, Muath Nairat, Ashley L. Tong, John I. Ogren, Stephanie M. Hart, Jianshu Cao, James N. Sturgis, Yuval Mazor, Gabriela S. Schlau-Cohen

Chemistry: Faculty Publications

In photosynthesis, absorbed light energy transfers through a network of antenna proteins with near-unity quantum efficiency to reach the reaction center, which initiates the downstream biochemical reactions. While the energy transfer dynamics within individual antenna proteins have been extensively studied over the past decades, the dynamics between the proteins are poorly understood due to the heterogeneous organization of the network. Previously reported timescales averaged over such heterogeneity, obscuring individual interprotein energy transfer steps. Here, we isolated and interrogated interprotein energy transfer by embedding two variants of the primary antenna protein from purple bacteria, light-harvesting complex 2 (LH2), together into a …

First-Principles Simulations Of Attosecond Transient X-Ray Absorption, Min Chen

LSU Doctoral Dissertations

The first part of this dissertation presents calculations of the extinction spec- tra of gold-silver/silver-gold core-shell nanospheres. The goal of this projectsis to get a deeper understanding of surface plasmonic resonance in metal nanospheres with core-shell geometry. Here, we used the finite-difference time-domain (FDTD) method and total-field/scattered-field (TFSF) framework to compute the extinction spectra of nanoparticles to determine the geometry of gold-silver/silver-gold core-shell nanoparticles. This supported experimental work on monitoring the growth dynamics of colloidal gold- silver/silver-gold core-shell nanoparticles using in situ second harmonic generation (SHG) and extinction spectroscopy.

The second and main project involved simulating attosecond transient spectra for …

Temperature-Pressure Phase Diagram Of Confined Monolayer Water/Ice At First-Principles Accuracy With A Machine-Learning Force Field, Bo Lin, Jian Jiang, Xiao Cheng Zeng, Lei Li

Department of Chemistry: Faculty Publications

Understanding the phase behaviour of nanoconfined water films is of fundamental importance in broad fields of science and engineering. However, the phase behaviour of the thinnest water film – monolayer water – is still incompletely known. Here, we developed a machine-learning force field (MLFF) at first-principles accuracy to determine the phase diagram of monolayer water/ice in nanoconfinement with hydrophobic walls. We observed the spontaneous formation of two previously unreported high-density ices, namely, zigzag quasi-bilayer ice (ZZ-qBI) and branched-zigzag quasi-bilayer ice (bZZ-qBI). Unlike conventional bilayer ices, few inter-layer hydrogen bonds were observed in both quasi-bilayer ices. Notably, the bZZ-qBI entails a …

Cationic Divalent Metal Sites (M = Mn, Fe, Co) Operating As Both Nitrene-Transfer Agents And Lewis Acids Toward Mediating The Synthesis Of Three- And Five-Membered N-Heterocycles, Suraj Kumar Sahoo, Brent Harfmann, Lin Ai, Qiuwen Wang, Sudip Mohapatra, Amitava Choudhury, Pericles Stavropoulos

Chemistry Faculty Research & Creative Works

The tripodal compounds [(TMG₃trphen)M^II-solv](PF₆)₂ (M = Mn, Fe, Co; solv = MeCN, DMF) and bipodal analogues [(TMG₂biphen)M^II(NCMe)_x](PF₆)₂ (x = 3 for Mn, Fe; x = 2 for Co) and [(TMG₂biphen)M^IICl₂] have been synthesized with ligands that feature a triaryl- or diarylmethyl-amine framework and superbasic tetramethylguanidinyl residues (TMG). The dicationic M(II) sites mediate catalytic nitrene-transfer reactions between the imidoiodinane PhI═NTs (Ts = tosyl) and a panel of styrenes in MeCN to afford aziridines and low yields of imidazolines (upon …

Biological Formation Of Ethylene, Robert P. Hausinger, Simahudeen Bathir Jaber Sathik Rifayee, Midhun George Thomas, Shramana Chatterjee, Jian Hu, Christo Christov

Michigan Tech Publications

This review summarizes the structures, biochemical properties, and mechanisms of two major biological sources of ethylene, the ethylene-forming enzyme (EFE) and 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACCO). EFE is found in selected bacteria and fungi where it catalyzes two reactions: (1) the oxygen-dependent conversion of 2-oxoglutarate (2OG) to ethylene plus three molecules of CO2/bicarbonate and (2) the oxidative decarboxylation of 2OG while transforming l-arginine to guanidine and l-Δ1-pyrroline-5-carboxylic acid. ACCO is present in plants where it makes the plant hormone by transforming ACC, O2, and an external reductant to ethylene, HCN, CO2, and water. Despite catalyzing distinct chemical reactions, EFE and …

Identification Of Unsuccessful Students In General Chemistry, G. Robert Shelton, Joseph M. Simpson, Diana Mason

All Faculty Scholarship (Archived)

The Networking for Science Advancement (NSA) team collected data from multiple general chemistry courses at nine universities within a broad geographic setting in a majority-minority US state. Data include diagnostic scores on the Math-Up Skills Test (MUST), quantitative literacy/quantitative reasoning (QL/QR) quiz, along with student demographics, and overall course grades. From these data the team determined how automaticity skills in procedural arithmetic and quantitative literacy and reasoning can be used to predict success in lower-division chemistry courses. By expanding this dataset, we extended our investigations to discover what characterizes successful and unsuccessful students in general chemistry, first and second semesters …

Predictability Of The Must (Math-Up Skills Test), Diana Mason, G. Robert Shelton

All Faculty Scholarship (Archived)

In the USA for the most part, completion of a first-semester general chemistry (Chem I) course lays the foundation deemed necessary for understanding second-semester general chemistry (Chem II) topics. Successful completion of Chem I and II gives students permission to progress to organic chemistry I (O-Chem). A series of studies undertaken by the NSA (Networking for Science Advancement) Texas team began in 2016. Texas is one of five majority-minority states in the USA and hosts a significant Hispanic population. The purpose of this research line is to evaluate the influence of basic arithmetic automaticity (what students can do without a …

The Effect Of Heat Treatment And Chemical Treatment On Natural Fibre To The Durability Of Wood Plastic Composites – A Review, Nuratiqah Asyiqin Mohd Nasharudin, Nur Fatihah Sulaiman, Nurul Aziemah Mohammad, Wan Nor Raihan Wan Jaafar, Falah Abu Dr., Siti Norasmah Surip

Journal of Materials Exploration and Findings

The application of WPC is not only limited to indoor applications but has been extended to exterior applications where properties of WPC could compromise during service life. WPC was derived from wood fiber of various sizes to reinforce polymers. Wood fiber has the advantage of a cheaper price, being abundantly available, and ease of processing, however, the critical factor is its hydrophilic nature, where moisture absorption is likely to occur. Thus, treatments for reducing the hydrophilicity of wood fibers are applied. By treatment of wood fiber, the surface impurities were removed, leaving the roughened surface of fibers, thus providing a …

Study On The Self-Repairing Effect Of Nanoclay In Powder Coatings For Corrosion Protection, Marshall S. Yang, Jinbao Huang, Hui Zhhang, James Noel, Yolanda S. Hedberg, Jian Chen, Ubong Eduok, Ivan Barker, Jeffrey D. Henderson, Chengqian Xian, Haiping Zhang, Jesse Zhu

Chemistry Publications

Powder coatings are a promising, solvent-free alternative to traditional liquid coatings due to the superior corrosion protection they provide. This study investigates the effects of incorporating montmorillonite-based nanoclay additives with different particle sizes into polyester/triglycidyl isocyanurate (polyester/TGIC) powder coatings. The objective is to enhance the corrosion-protective function of the coatings while addressing the limitations of commonly employed epoxy-based coating systems that exhibit inferior UV resistance. The anti-corrosive and surface qualities of the coatings were evaluated via neutral salt spray tests, electrochemical measurements, and surface analytical techniques. Results show that the nanoclay with a larger particle size of 18.38 µm (D50, …

Scope And Mechanistic Studies On The Ruthenium-Catalyzed Multicomponent Deaminative C–H Coupling Reaction Of Phenols With Aldehydes And Enamines For The Formation Of Xanthene And Dioxacyclic Derivatives, Nuwan Asanka Pannilawithana, Mina Son, Donghun Hwang, Mu-Hyun Baik, Chase S. Yi

Chemistry Faculty Research and Publications

The in situ generated catalytic system from the tetranuclear Ru–H complex [(PCy₃)(CO)RuH]₄(O)(OH)₂ (1) with 3,4,5,6-tetrachloro-1,2-benzoquinone (L1) has been found to mediate a multicomponent deaminative coupling reaction of phenols with aldehydes and enamines to form xanthene products. The multicomponent C–H coupling reaction of phenols with 2-hydroxybenzaldehydes and cyclic enamines efficiently installed the tricyclic 1,3-dioxacin derivatives, while the analogous coupling reaction of phenols with 2-hydroxybenzaldehydes and triethylamine selectively formed bicyclic 1,5-dioxacyclic derivatives. The density functional theory (DFT) calculations established two energetically viable mechanistic pathways for the formation of xanthene products, in which both …

Strong Ultrafast Demagnetization Due To The Intraband Transitions, G.P. Zhang

University Honors Program

No abstract provided.

Investigating The Effects Of The Sugar Alcohol Osmolytes Glycerol And Erythritol In Aot Reverse Micelles, Animesh Dali '24, Bridget Gourley

Student Research

Water is a polar molecule that participates in hydrogen bonding and proton transfer. Geometric confinement and water’s interactions with osmolytes (small water soluble compounds) affect the ability of water molecules to hydrogen bond and transfer charges. Study of this behaviour of water with different osmolytes in controlled environments will help us develop predictive models. In our study, we have prepared Sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles (RM) in 2,2,4-Trimethylpentane (Isooctane). Our principle osmolytes were the straight chain sugar alcohols glycerol and erythritol. Study of water-osmolyte behaviour in the small and confined pool of a reverse micelle allows us examine the difference …

Investigation Of Vitamin D Metabolites Using Different Ion Mobility-Mass Spectrometry (Im-Ms) Methods, Selena Kingsley, Christopher D. Chouinard

Chemistry Summer Research Program

No abstract provided.

Development Of A Rapid Sars-Cov-2 Nucleocapsid Assay Using Buoyant And Magnetic (Bam) Beads, Spasenija Radenovic, Zahra Karimpourkalou, Chaunlei Wang, Jeffrey N. Anker

Chemistry Summer Research Program

No abstract provided.

Isolation Of Bovine Milk-Derived Exosomes Via A Polyester Capillary- Channeled Polymer (C-Cp) Fiber Stationary Phase, Jerisa Pimentel, Carolina Mata, R. Kenneth Marcus

Chemistry Summer Research Program

No abstract provided.

Nuclear Magnetic Resonance Studies Of Potential Environmental Contaminants Interacting With Dna, Anna Hopkins, Leah B. Casabianca

Chemistry Summer Research Program

No abstract provided.

Big Data For A Deep Problem: Exploring Natural Deep Eutectic Solvent (Nades) Properties Through Rdkit And Data Analytics, Grayson Weavil, Lucas B. Ayres, Carlos D. Garcia

Chemistry Summer Research Program

No abstract provided.

The Dynamic Shift To Green Chemistry: Investigating The Spectral Behavior Of Natural Deep Eutectic Solvents (Nades) And Their Performance As Maldi-Tof Matrices, Grayson Weavil, Lucas B. Ayres, Miguel Jose-Bueno, Rakesh Sachdeva, Carlos D. Garcia

Chemistry Summer Research Program

No abstract provided.

Investigation Of Vitamin D Metabolites Using Different Ion Mobility-Mass Spectrometry (Im-Ms) Methods, Selena Kingsley, Christopher D. Chouinard

Chemistry Summer Research Program

No abstract provided.

Prediction Of Dislocation Densities In Pure Metals And Alloys, J. Garey Weaver, Enrique Martinez

Chemistry Summer Research Program

No abstract provided.

Supramolecular Π-Donor/Acceptor Arrays Based On Metal-Organic Cage Inclusion Complexes, Sean Hannigan, Evan Thibodeaux, Sourav Saha

Chemistry Summer Research Program

No abstract provided.