Chemistry Commons^™

Variable Pressure Nuclear Magnetic Resonance Studies Of Ionic Liquids And Electrophoretic Probe Design, Armando Julio Rua

Dissertations, Theses, and Capstone Projects

Energy storage materials play a key role in, efficient, clean, and versatile use of energy, and are crucial for the exploitation of renewable energy. The improve efficiency of energy use stimulates the development of energy storage such as batteries or super capacitors, toward higher power and energy density, which significantly depends upon the advancement of new materials used in these devices. The new materials need better understanding and description in the electrochemical properties. Nuclear Magnetic Resonance (NMR) has been an important tool in the characterization of ionic liquids and solids. The measurements of the relaxation times and the diffusion coefficient …

Study Of Polyaniline For Use In An Organic Field Effect Transistor, Thomas Martin Sprinkle

Chemistry & Biochemistry Theses & Dissertations

Polyaniline's emeraldine base form was synthesized via chemical polymerization in HCl acidic media utilizing ammonium persulfate as the oxidant. Synthesis was done at room temperature and -30 'C and characterized for differences by X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. Methanol soxhlet extraction was done to increase number average molecular weight from 77,400 to 81,000 and decrease the poly dispersity index from 3.82 to 2.14. Films were cast using N, N'- Dimethylpropyleneurea and N-Methylpyrrolidone and showed poor mechanical properties upon acidic doping.

Cyclic voltammetry was done with HC1 as the acidic media and an ITO coated slide as the …

Preparation Of Cyclohexenones From Acyclic (Pentadienyl)Iron(1+) Cations: Synthetic Studies Directed Toward The A-Ring Of Dihydrotachysterols, Charles Felix Manful, William A. Donaldson

Chemistry Faculty Research and Publications

The reaction of tricarbonyl(3-methylpentadienyl)iron(1+) cation (7) with stabilized carbon nucleophiles affords 4-methyl-5-substituted cyclohexenones. Reaction of 7 with sodium bis[(+)-2-phenylcyclohexyl]malonate afforded a mixture of diastereomers (de = 60 %); the diastereomeric allylic alcohols resulting from Luche reduction of this mixture were separable by column chromatography. Issues in diastereoselectivity in approaches to synthons for the A-ring of the tachysterols from these cyclohexenones are reported.

Interactive Tool For Visualization Of Adiabatic Adjustment In Aph Coordinates For Computational Studies Of Vibrational Motion And Chemical Reactions, Alexander Teplukhin, Dmitri Babikov

Chemistry Faculty Research and Publications

The adiabatically-adjusting principal-axes hyperspherical (APH) coordinates reviewed in this letter are one of the best coordinate sets developed for computational treatment of spectroscopy and dynamics of triatomic molecules. Unfortunately, it is not so easy to understand and interpret them, compared to other simpler coordinates, like valence coordinates or Jacobi coordinates. To address this issue, we developed a desktop application called APHDemo. This tool visualizes the process of adjustment of the APH coordinates to the shape of a triatomic molecule during molecular vibrations or chemical reaction, and helps to understand their physical meaning without going into complicated math.

Molecular Interactions With Ice: Molecular Embedding, Adsorption, Detection, And Release, K D. Gibson, Grant G. Langlois, Wenxin Li, Daniel Killelea, S J. Sibener

Chemistry: Faculty Publications and Other Works

The interaction of atomic and molecular species with water and ice is of fundamental importance for chemistry. In a previous series of publications, we demonstrated that translational energy activates the embedding of Xe and Kr atoms in the near surface region of ice surfaces. In this paper, we show that inert molecular species may be absorbed in a similar fashion.We also revisit Xe embedding, and further probe the nature of the absorption into the selvedge. CF4 molecules with high translational energies (≥3 eV) were observed to embed in amorphous solid water. Just as with Xe, the initial adsorption rate is …

Regulating Signal Enhancement With Coordination-Coupled Deprotonation Of A Hydrazone Switch, Justin T. Foy, Debdas Ray, Ivan Aprahamian

Dartmouth Scholarship

Proton relay plays an important role in many biocatalytic pathways. In order to mimic such processes in the context of molecular switches, we developed coordination-coupled deprotonation (CCD) driven signaling and signal enhancement sequences. This was accomplished by using the zinc(ii)-initiated CCD of a hydrazone switch to instigate an acid catalyzed imine bond hydrolysis that separates a quencher from a fluorophore thus leading to emission amplification. Because CCD is a reversible process, we were able to show that the catalysis can be regulated and turned “on” and “off” using a metalation/demetalation cycle.

An Expeditious Green Route Toward 2-Aryl-4- Phenyl-1h-Imidazoles, Debasish Bandyopadhyay, Lauren C. Smith, Daniel R. Garcia, Ram Naresh Yadav, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Background: Azaheterocycles are an important class of compounds because of their highly potent medicinal activities, and the imidazole subcategory is of special interest in regard to drug discovery research.

Findings: An expeditious synthetic protocol of 2-aryl-4-phenyl-1H-imidazoles has been accomplished by reacting phenylglyoxal monohydrate, ammonium acetate, and aldehyde under sonication. Following this green approach a series of 2-aryl-4-phenyl-1H-imidazoles has been synthesized using diversely substituted aldehydes.

Conclusions: A rapid and simple synthetic procedure to synthesize diversely substituted 2-aryl-4-phenyl-1H-imidazoles has been reported. Other salient features of this protocol include milder conditions, atom-economy, easy extraction, and minimum wastes. The present procedure may find application …

Crystal Engineering Of Functional Metal-Organic Material Platforms For Gas Storage And Separation Applications, Sameh Khamis Elsaidi

USF Tampa Graduate Theses and Dissertations

Metal-organic materials (MOMs) represent a unique class of porous materials that captured a great scientific interest in various fields such as chemical engineering, physics and materials science. They are typically assembled from metal ions or metal clusters connected by multifunctional organic ligands. They represent a wide range of families of materials that varied from 0D to 3D networks: the discrete (0D) structures exemplified by metal-organic polyhedra (MOPs), cubes and nanoballs while the polymeric 1D, 2D and 3D structures exemplified by coordination polymers (CPs). Indeed, the porous 3D structures include metal-organic frameworks (MOFs), porous coordination polymers (PCPs) and porous coordination networks …

Trace Gas Emissions From Combustion Of Peat, Crop Residue, Domestic Biofuels, Grasses, And Other Fuels: Configuration And Fourier Transform Infrared (Ftir) Component Of The Fourth Fire Lab At Missoula Experiment (Flame-4), C. E. Stockwell, R. J. Yokelson, S. M. Kreidenweis, A. L. Robinson, P. J. Demott, R. C. Sullivan, J. Reardon, K. C. Ryan, D. W.T. Griffith, L. Stevens

Chemistry and Biochemistry Faculty Publications

During the fourth Fire Lab at Missoula Experiment (FLAME-4, October-November 2012) a large variety of regionally and globally significant biomass fuels was burned at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particle emissions were characterized by an extensive suite of instrumentation that measured aerosol chemistry, size distribution, optical properties, and cloud-nucleating properties. The trace gas measurements included high-resolution mass spectrometry, one-and two-dimensional gas chromatography, and open-path Fourier transform infrared (OP-FTIR) spectroscopy. This paper summarizes the overall experimental design for FLAME-4-including the fuel properties, the nature of the burn simulations, and the instrumentation employed-and then focuses on …

Resin-Supported Arylstannanes As Precursors For Radiolabeling With Iodine: Benzaldehydes, Benzoic Acids, Benzamides, And Nhs Esters, Mustafa Janabi, Catherine M. Pollock, Ann-Marie Chacko, Duncan H. Hunter

Chemistry Publications

A highly cross-linked polystyrene resin bearing a reactive chlorostannane moiety 1 has been used to generate a variety of arylstannane radiopharmaceutical precursors for no-carrier-added radioiodination. The resins were characterized for their solvent compatibility and sensitivity to acid cleavage. Resin-supported arylstannanes synthesized via their aryl lithium analogues include 3- and 4-stannylbenzaldehydes, 3- and 4-stannylbenzoic acids, and 3- and 4-N-succinimidyl benzoates. A three-step route to the resin-supported stannylbenzoic acids 12a/b was developed through resin-supported benzaldehydes 11a/b. The aldehyde to acid conversion efficiency is >90%, and acid loading capacities of 0.66–0.94 mmol/g were obtained. Resin-supported N-succinimidyl benzoates 16a/b …

Development Of Novel Efficient Organocatalytic Reactions For The Construction Of Complex Molecular Architectures, Aiguo Song

Chemistry and Chemical Biology ETDs

Facile construction of synthetically and medicinally significant optically active molecular architectures from simple and readily available materials via catalytic enantioselective cascade processes is the cental goal in organic synthesis. Toward this end, my Ph.D. work focuses on the development of novel organocatalytic asymmetric cascade reactions and their application in the synthesis of versatile molecular structures. A novel amine catalyzed decarboxylative enantioselective Diels—Alder reaction between aldehydes and readily available coumarin-3-carboxylic acids as dienophiles via dienamine catalysis has been realized. Notably, the decarboxylation facilitates the release of the catalyst in the Diels—Alder reaction adducts and achieves high reaction efficiency in terms of …

Epoxy Catalyzed Sol-Gel Method For Pinhole-Free Pyrite Fes2 Thin Films, S. Kment, H. Kmentova, A. Sarkar, R. J. Soukup, N. J. Ianno, D. Sekora, J. Olejnicek, P. Ksirova, J. Krysa, Z. Remes, Z. Hubicka

Department of Electrical and Computer Engineering: Faculty Publications

The uniform pinhole-free iron disulfide (FeS₂) pyrite thin films were fabricated. In the first step the FeO(OH)_x xerogel solution was synthetized by means of a novel epoxy catalyzed sol-gel method and next spin-coated onto various substrates to form the thin films. In the second step the xerogel coatings were annealed to yield hematite (α-Fe₂O₃) films, which were transformed into pyrite by chemical sulfurization. Among the main deposition parameters studied were the temperature of xerogel-hematite transformation and the optimal sulfurization temperature and duration. It has been observed that 15 min sulfurization at the temperature …

Criteria For Evolution Of Successful Proteins: Fold Fitness And Domain Dynamics Explored, Tyrel Bryan

Chemistry and Chemical Biology ETDs

The Haloacid Dehalogenase Superfamily (HADSF) is a ubiquitous family of enzyme with more than 32,000 members. A variety of reactions are catalyzed by HAD members, but a majority of HAD members are phosphatases. Dephosphorlyation of organophosphate metabolites are carried out in the conserved Rossmann-like core domain. The Rossman-like core domain houses the conserved active site residues necessary for catalysis and also supports domain inserts associated with substrate binding. This dissertation will focus primarily on investigating fold fitness and domain dynamics of HAD proteins more specifically three C2 capped proteins. The first part will focus on whether or not the prevailing …

Development Of Novel Small Molecules For Imaging And Drug Release, Yanting Cao

Chemistry and Chemical Biology ETDs

Small organic molecules, including small molecule based fluorescent probes, small molecule based drugs or prodrugs, and smart multifunctional fluorescent drug delivery systems play important roles in biological research, drug discovery, and clinical practices. Despite the significant progress made in these fields, the development of novel and diverse small molecules is needed to meet various demands for research and clinical applications. My Ph.D study focuses on the development of novel functional molecules for recognition, imaging and drug release. In the first part, a turn-on fluorescent probe is developed for the detection of intracellular adenosine-5'-triphosphate (ATP) levels based on multiplexing recognitions. Considering …

The Interplay Between Charge Transfer, Rehybridization, And Atomic Charges In The Internal Geometry Of Subunits In Noncovalent Interactions, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

When a noncovalent bond is formed, there is frequently some charge transfer from one subunit to the other. The interaction also causes changes in the atomic charges and hybridization patterns of bonding orbitals. The manner in which these various effects combine to cause elongations or contractions of bonds within the individual subunits is examined. In both the cases of CH···O H-bonds and P···N pnicogen bonds, the bond length changes are consistent with the guiding principles generally known as Bent’s rules.

Spectroscopic Studies Of Conjugated Polymer Nanostructures And Polymer/Acceptor Blends, Jian Gao

Chemistry and Chemical Biology ETDs

This dissertation presents the results of investigations into organic semiconducting systems at the nano- to mesoscales through spectroscopic and electrical imaging techniques. Particular emphasis was put on capturing the role of conformation and morphology on electronic properties and processes. The combination of experimental methods and data analysis techniques used in this work reveals useful insights into the correlations between polymer structures and their photovoltaic device performance, and provide clues to developing better performing organic solar cells. The main approach of this work is using prototypical conjugated polymer systems, either ensemble or in their nanostructures, to study the solar cell active …

Stable Solar Cells Through Controlled Block Copolymer Self-Assembly And Cooperative Hydrogen Bonding Interactions, Fei Li

Chemistry and Chemical Biology ETDs

Current state-of-the-art polymer solar cells adopt the bulk-heterojunction (BHJ) morphologies where the electron donors (i.e. conjugated polymer) and electron acceptors (i.e. fullerenes) as active layers are mixed in an intimate way. The phase separation that modulates the exciton diffusion and charge transport in the current BHJ morphology is an uncontrolled process and thus results in random domain sizes of the polymer/fullerene blend. In addition, the polymer and fullerenes in the blend are intrinsically two immiscible materials and they tend to undergo macrophase separation eventually, which leads to deteriorated device performance. One way to address the abovementioned issues is to attach …

Theoretical Studies Of Transition Metal Catalysis, Ryan S. Johnson

Chemistry and Chemical Biology ETDs

Transition metal catalysis, being critical to nearly all aspects of the modern industrial world, is the focus of a series of theoretical studies which seek to elucidate the fundamental and electronic origins of enhanced chemical activity and selectivity. The application of density functional theory on extended single metal and alloyed surfaces, supported single metal atoms, and gas phase cationic species illuminate various aspects of transition metal catalysis in a wide range of enviornments. Adsorption, reactivity, and other mechanistic details developed here suggest possible mechanisms used to aid interpretation of experimental results and guide developement of future catalysts.

Identification And Quantification Of Gaseous Organic Compounds Emitted From Biomass Burning Using Two-Dimensional Gas Chromatography/Time-Of-Flight Mass Spectrometry, L. E. Hatch, W. Luo, J. F. Pankow, Robert Yokelson, C. Stockwell, K. C. Barsanti

Chemistry and Biochemistry Faculty Publications

The current understanding of secondary organic aerosol (SOA) formation within biomass burning (BB) plumes is limited by the incomplete identification and quantification of the non-methane organic compounds (NMOCs) emitted from such fires. Gaseous organic compounds were collected on sorbent cartridges during laboratory burns as part of the fourth Fire Lab at Missoula Experiment (FLAME-4), with analysis by two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC/TOFMS). The sensitivity and resolving power of GC×GC/TOFMS allowed the acquisition of the most extensive data set of BB NMOCs to date, with measure ments for 722 positively or tentatively identified compounds. Estimated emission factors (EFs) are presented …

Silyl Trifluoromethanesulfonate-Activated Para-Methoxybenzyl Methyl Ether As An Alkylating Agent For Thiols And Aryl Ketones, C. Wade Downey, Sarah E. Covington, Derek C. Obenschain, Evan Halliday, James T. Rague, Danielle N. Confair

Chemistry Faculty Publications

para-Methoxybenzyl methyl ether acts as an alkylating agent for thiols in the presence of trimethylsilyl trifluoromethanesulfonate and trialkylamine base in good yields (58-96%). Aryl ketones are alkylated under similar conditions, probably through an enol silane intermediate, also in high yields (67-95%). The active alkylating species is likely a p-methoxybenzyl cation.

2014 Scas Annual Meeting Program

Journal of the South Carolina Academy of Science

No abstract provided.

Genotypic And Phenotypic Characterization Of Aerosolized Bacteria Collected From African Dust Events, Christina A. Wilson, Robin L. Brigmon, Chris Yeager, Garriet W. Smith, Shawn W. Polson

Journal of the South Carolina Academy of Science

Twenty-one bacteria were isolated and characterized from air samples collected in Africa and the Caribbean by the United States Geological Survey (USGS). Isolates were selected based on preliminary characterization as possible pathogens. Identification of the bacterial isolates was achieved using 16S rRNA gene sequence analysis, fatty acid methyl esters (FAMEs) profiling, the BIOLOG Microlog^® System (carbon substrate assay), and repetitive extragenic palindromic (REP)-PCR analysis. The majority of isolates (18/21) were identified as species of the genus Bacillus. Three isolates were classified within the Bacillus cereus senso lato group, which includes Bacillus anthracis, Bacillus thuringiensis, and Bacillus …

Scas Officers And Council Members 2014-2015

Journal of the South Carolina Academy of Science

No abstract provided.

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

Crystal Structure Of A Polysamarium (Iii) Nitrate Chain Crosslinked By A Di-Cmpo Ligand, Julie A. Stoscup, Richard J. Staples, Shannon M. Biros

Peer Reviewed Articles

In the title compound poly[aqua­bis­(-nitrato-⁴O,O':O,O'')tetra­kis­(nitrato-²O,O'){₄-tetra­ethyl [(ethane-1,2-diyl)bis(aza­nedi­yl)bis­(2-oxo­ethane-2,1-di­yl)]di­phospho­nate-²O,O'}disamarium(III)], [Sm₂(NO₃)₆(C₁₄H₃₀N₂O₈P₂)(H₂O)]_n, a 12-coordinate Sm^III and a nine-coordinate Sm^III cation are alternately linked via shared bis-bidentate nitrate anions into a corrugated chain extending parallel to the a axis. The nine-coordinate Sm^III atom of this chain is also chelated by a bidentate, yet flexible, carbamoyl­methyl­phoshine oxide (CMPO) ligand and bears one water …

Scalable Synthesis Of 5,11-Diethynylated Indeno[1,2-B]Fluorene-6,12-Diones And Exploration Of Their Solid State Packing, Bradley D. Rose, Peter J. Santa Maria, Aaron G. Fix, Chris L. Vonnegut, Lev N. Zakharov, Sean R. Parkin, Michael M. Haley

Chemistry Faculty Publications

We report a new synthetic route to 5,11-disubstituted indeno[1,2-b]fluorene-6,12-diones that is amenable to larger scale reactions, allowing for the preparation of gram amounts of material. With this new methodology, we explored the effects on crystal packing morphology for the indeno[1,2-b]fluorene-6,12-diones by varying the substituents on the silylethynyl groups.

Measuring Activity Of Endothelial Nitric Oxide Synthase And Nanodisc Complex Through Nitrate Production, Christopher Verdi, Ghaith Altawallbeh, Mekki Bayachou

Undergraduate Research Posters 2014

Nitric oxide is an important bioregulator generated in various regions throughout the body by a family of isozymes referred to as Nitric Oxide Synthases (NOS). Within vascular endothelial cells, nitric oxide is generated from oxygen and arginine (amino acid) by endothelial nitric oxide synthases (eNOS). Within this environment nitric oxide plays a critical paracrine role, mainly anithrombotic and anti-atherosclerotic. This is accomplished by vessel dilation and prevention of platelet and leukocyte aggregation and adherence to the vessel wall. The activity of the eNOS enzyme has been studied within solution and is well understood. However, the impact that the lipid bilayer …

Advances In Molecular Quantum Chemistry Contained In The Q-Chem 4 Program Package, Yihan Shao, Zhengting Gan, Evgeny Epifanovsky, Andrew T. B. Gilbert, Michael Wormit, Shervin Fatehi

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

A summary of the technical advances that are incorporated in the fourth major release of the Q-CHEM quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of …

Inhibition Of The Thioesterase Activity Of Human Fatty Acid Synthase By 1,4- And 9,10-Diones, Herman H. Odens

Faculty Works

Fatty acid synthase (FASN) is the enzyme that synthesizes fatty acids de novo in human cells. Although FASN is generally expressed at low levels in most normal tissues, its expression is highly upregulated in many cancers. Consistent with this notion, inhibition of FASN activity has demonstrated potential to halt proliferation and induce cell death in vitro and to block tumor growth in vivo. Consequently, FASN is widely recognized as a valuable therapeutic target. In this report, we describe a variety of 1,4-quinones and 9,10- anthraquinones, including several natural compounds and some newly synthesized compounds, that potently inhibit the thioesterase (TE) …

Unfolded Protein Response Activation Reduces Secretion And Extracellular Aggregation Of Amyloidogenic Immunoglobulin Light Chain, Christina B. Cooley, L. M. Ryno, L. Plate, G. J. Morgan, J. D. Hulleman, J. W. Kelly, R. L. Wiseman

Chemistry Faculty Research

Light-chain amyloidosis (AL) is a degenerative disease characterized by the extracellular aggregation of a destabilized amyloidogenic Ig light chain (LC) secreted from a clonally expanded plasma cell. Current treatments for AL revolve around ablating the cancer plasma cell population using chemotherapy regimens. Unfortunately, this approach is limited to the ∼70% of patients who do not exhibit significant organ proteotoxicity and can tolerate chemotherapy. Thus, identifying new therapeutic strategies to alleviate LC organ proteotoxicity should allow AL patients with significant cardiac and/or renal involvement to subsequently tolerate established chemotherapy treatments. Using a small-molecule screening approach, the unfolded protein response (UPR) was …