Chemistry Commons^™

In Search Of The Hot Spot., Danielle M Mcrae, François Lagugné-Labarthet

Chemistry Publications

Tip-enhanced spectroscopy and its Raman variant, tip-enhanced Raman spectroscopy (TERS), provide the possibility to spatially resolve the vibrations of a single molecule when combined with ultra-high vacuum technology, but this technique suffers from poor time resolution2,3. On the other hand, surface-enhanced Raman spectroscopy (SERS) is a more common technique, and is used for many imaging and bioanalytical applications, still with single molecule sensitivity but, unlike TERS, without spatially resolved molecular imaging capabilities4. In SERS, the roughness and geometric characteristics of metallic surfaces (in general Al, Ag or Au) are exploited to enable high spatial …

Hybrid Catalysis For The Direct Addition Of Unactivated Aldehydes And Ketones To Alkenes And Alkynes, Jacob Porter

Dissertations (1934 -)

Reactions for the alpha functionalization of carbonyl compounds are important for the synthesis of complex organic materials such as pharmaceuticals, agrochemicals, and natural products. Current methodology used to perform these reactions is inefficient in that pre-activated coupling partners or sensitive catalysts are usually required. Described herein is the study and development of bifunctional and dual catalytic systems for carbon-carbon bond formation via the direct addition of unactivated carbonyl compounds to unactivated alkenes/alkynes. A dual catalyst system is one which utilizes two distinct catalysts to simultaneously activate separate reactants, and in a bifunctional catalyst the two catalytic components are present separately …

Macromolecular Engineering Of Biomass Polymers And Stimuli-Responsive Materials Towards Enhanced Thermomechanical Properties, Meghan E. Lamm

Theses and Dissertations

Commodity polymers are used in every aspect of daily life, and most of these polymeric materials are synthesized using petroleum-derived sources. There are direct environmental consequences to this petroleum dependence including greenhouse gas emissions and climate change. Biomass-based polymers show promise for the mitigation on negative environmental impact, in comparison with petroleum-derived counterparts. However, some biopolymers suffer from low chain entanglement due to bulky or long side chain structures, resulting in poor mechanical properties. In this dissertation work, macromolecular engineering is used to design biomass-derived polymers featuring a variety of structures and functionalities. Additionally, biopolymer properties (including thermomechanical enhancement) and …

Chemical Speciation In Silver Bow And Blacktail Creeks: Implications For Bioavailability And Restoration, Johnathan Feldman

Graduate Theses & Non-Theses

Silver Bow and Blacktail Creeks, contaminated with toxic elements from mining, present a need for remediation and restoration. Trace elements are present in elevated concentrations, particularly copper. Determining element speciation will allow informed consideration of effective restoration strategies, by providing a foundation for assessing bioavailability and toxicity. The three goals are: determine how speciation varies between seasons and sites in four impacted sites from the greater Butte Area One, an impacted downstream site known as Santa, and a control site on Upper Blacktail Creek known as Blacktail; how these variations influence bioavailability and toxicity; and what causes these variations. Total …

Synthesis Of Bis(Imino)Pyridine Iron(Ii) Complexes And Development Of Bis(Imino)Pyridine Iron(Ii) Catalyzed Carbene Transfer Reactions, Ban Wang

Masters Theses & Specialist Projects

Metal catalysis of symmetric and asymmetric carbene transfer reactions has been widely applied in natural product synthesis and material science over years. Metal carbene can be easily generated from the extrusion of nitrogen under the catalysis of metal complexes to further undergo various organic reactions, O/N/C-H insertions, cycloadditions, and ylide formations. Currently, the dominant effective catalysts for carbene reactions are built with expensive precious metal, for example, rhodium, ruthenium, palladium, gold. Notably, the effective reactivity and enantioselectivity of the dirhodium(II) catalysts are researched and established over the decades. However, the use of precious metal catalysts is the major source of …

Chemistry Matters Fall 2019, Otterbein University Chemistry Department

Chemistry Matters Department Newsletter

In this issue:

A Word from the Chair, Homecoming Tailgate, Students Present at National Meetings, Class of 2015 Updates, Part-Time Faculty Recognized for Outstanding Teaching, Writing Poems, Periodically, Faculty Sabbatical at the Interface of Chemistry and Art, Fall ACS Meeting, Summer Student Internships, 2019 Science Lecture Series, Class of 2019 Updates

Evaluation Of A New Approach For Qualitative Gas Analysis Based On Diffusion Properties, Abdalla Jamal Abunamous

Theses

The design and construction of a 6-channel parallel gas diffusion system and its application to evaluating the proposed novel approach for gas fingerprinting are described. The present gas diffusion system allows the simultaneous recording of the pressure accumulation of the permeating test gas behind six different gas permeable membranes, respectively. The obtained simultaneous diffusion rates through different membranes demonstrated clear potential as a new technique for qualitative gas identification of the ten test gases used in the present work. The test gases were helium, neon, argon hydrogen, nitrogen, carbon dioxide, methane, ethane, propane, and ethylene, which are representative examples of …

Double-Click Enables Synthesis Of Chemical Libraries For Drug Discovery, Joseph J. Topczewski, En Chih Liu

Chemistry Faculty Research & Creative Works

No abstract provided.

Electrochemistry Of Illusive Barbosalite, Fe²⁺Fe³⁺ 2(Po₄)₂(Oh)₂: An Iron Phosphate Related To Lipscombite Structure, Prashanth Sandineni, Kartik Ghosh, Amitava Choudhury

Chemistry Faculty Research & Creative Works

Barbosalite, an iron hydroxy-phosphate belonging to the family of Lazulite has been synthesized using hydrothermal route and its electrochemical property is investigated for the first time with respect to Li-ion batteries. The structure, as determined from single-crystal X-ray diffraction data, built up of undulating layers of FeO₆ octahedra, consisting of trimers and PO₄ tetrahedral units. Magnetic susceptibility measurements show predominant overall anti-ferromagnetic interactions and room temperature 57Fe Mössbauer spectroscopic studies confirm the mixed 3+ and 2+ oxidation states of Fe in the compound. The compound is stable up to 400°C and undergo facile electrochemical lithium insertion. Galvanostatic charge-discharge …

Cdse Quantum Dot Surface Chemistry Thermodynamics Via Isothermal Titration Calorimetry: An Emphasis On The Fundamentals, Megan Y. Gee

Theses and Dissertations

For several decades, the study and development of colloidal semiconductor nanocrystals, or quantum dots (QD), has become a rich field heralding improved integration into applications ranging from photovoltaics and photocatalysis to biomedical imaging and drug delivery. CdxSey is the most extensively studied QD system, however numerous compositional details still confound the nanocrystal field. Although CdSe QDs with native ligand coatings can show high fluorescence quantum yield and may be suitable for some applications, often times these original ligand layers are comprised of long aliphatic chains that preclude incorporation into biological matrices or severely impede charge transfer – depending on the …

Organic Chemistry Ii Lab Manual, Caitlyn Bailey

Senior Honors Theses

This project aims to supply a full lab manual and grading key for Organic Chemistry II, a class often taken by sophomores in Liberty University’s science degree programs. Properly applied laboratory experiments create a beneficial learning environment for science students by using hands-on procedures to transform intangible lecture concepts into concrete demonstrations. Lab work also fosters the development of problem-solving and critical-thinking skills that students need in research and the workplace. Thus, having a comprehensive lab manual is critical to students’ success and understanding in this upper-level class. This project adds to the experiments of Organic Chemistry II lab through …

Molecular Modeling Labs For Freshman Chemistry I, Suzanne Ellenberger, Sara Blankenship, Ana West, Rupa Gokal, Daphne Norton, Nick Nguyen, Cynthia Tope

Chemistry Ancillary Materials

This set of laboratory exercises for Freshman Chemistry I was created under a Round Thirteen Mini-Grant for Ancillary Materials Creation and Revision. The exercises are intended for the AMPAC and Agui chemistry software program, and topics covered include Physical Properties, VSEPR, and a molecular modeling activity.

Practice Problem Worksheets For Freshman Chemistry I (Openstax Chemistry 2nd Edition), Suzanne Ellenberger, Wenjian Du, Sara Blankenship, Ana West, Rupa Gokal, Joel Caughran

Chemistry Ancillary Materials

This set of practice problem worksheets for Freshman Chemistry I was created under a Round Thirteen Mini-Grant for Ancillary Materials Creation and Revision. These materials are made to supplement OpenStax Chemistry (https://openstax.org/details/books/chemistry-2e).

Topics covered include:

• Atoms, Molecules, and Ions;
• Gases;
• Compounds;
• Solutions and Colloids;
• Stoichiometry

Mapping The Exterior Of A Mastodon Tusk Using Uv-Vis Diffuse Reflectance, Teresa Feldman

Fall 2019 - Chemical Analysis Class Projects

The 12-foot, 600-pound mastodon tusk was discovered in Hampton, Iowa, in the 1930s by a man digging in the gravel. It was the largest discovered mastodon tusk until the 1970s. The tusk was donated to UNI in 1933, under Dr. Cable, and put on display at the UNI Museum in the 1960s. Over the years, there have been many efforts to conserve the tusk, but it has still sustained breakage and water damage. It has also been subject to inadvertent degradation from some of the previous conservation efforts.

The purpose of the research conducted was to create a spectral map …

Nir Mapping Of The Mastodon Tusk Layers, Carli Jo Russenberger

Fall 2019 - Chemical Analysis Class Projects

This tusk was unearthed in September of 1933 in the town of Hampton, Iowa. About two feet from the proximal end, the tip broke upon extrication. In order to preserve this archaeological finding, many layers of lacquers, plasters, and varnishes were applied. 3 The layers of preservation are not well identified, as well as the timing of application.

By using the Near Infrared (NIR) technique, infrared light is applied to the tusk and wavelengths are absorbed. The absorbances can help determine the functional groups of the restoration materials in the NIR range of 4,000 to 10,000 wavenumbers.

The objective of …

Fluorescence Mapping Of Materials On Mammut Americanum, Shaylah Peyton Mccool

Fall 2019 - Chemical Analysis Class Projects

Mammut Americanum , more commonly known as the American Mastodon, is an extinct species found throughout North and Central America. Dated from either the Aftonian or Yarmouth age (120,000 to 200,000 B.C.E.), a 12 foot, 600 pound tusk of a mastodon was discovered in Hampton, Iowa in the 1930’s.

In 1933, it was brought to the University of Northern Iowa for comprehensive research and preservation. The tusk was covered in unknown materials such as varnish, spackle, lacquer, and shellac in an attempt to preserve it before putting it on display in the UNI Museum in the 1960’s. Currently, the tusk …

Identification Of Dye Compounds In Chinese Artifacts By Gc Ms, Pratima Raut

Fall 2019 - Chemical Analysis Class Projects

UNI Museum homes wide variety of textile artworks.
Many of them have historical significance. Two of them are UNIM 2005.2.24 (Tapestry) and UNIM1986.14.1985.1.124 (Hanging)

Figure 1: UNIM 2005.2.24 (Tapestry)
Rectangular Textile
Dimension: 36cm × 69cm
Dark blue silk embroidery of an old bearded man believed to be Chinese god, Shou Hsing
Contrasting floral designed 1'' border
“Made in China” stamp on the plain cotton fabric back

Figure 2: UNIM 1986.14.1985.1.124 (Hanging)
Silk fabric
Dimension 158cm × 74cm
Dimension: 36cm × 69cm
Depiction of an elderly man like the one in Chinese folklore about prosperity
Assumed to be of Chinese origin

Fiber-Optic Spectroscopy Of Mandarin Square Textile Artifacts, Joseph Leonard Tibbs

Fall 2019 - Chemical Analysis Class Projects

Mandarin Squares were officially used from the Ming Dynasty (1391 AD) until the end of the Qing Dynasty (1912), though the tradition dates back even further

These badges were instruments of politics and courtly etiquette, and the animal subject denoted rank and position

Design subject to artistic movements as tastes changed

Common elements include symbolism, good luck charms, flight/motion, mystical beasts (below)

Traditionally worn as two panels on either side of a riding jacket, therefore split by a seam in the middle (see right)

Above: Data Collection using handheld IR Fiber Optic probe Below: A sample page from the Kusakizome …

Ultra-Fast Sensors To Study The Fundamental Neurochemistry Underlying Disease, Alyssa West

Theses and Dissertations

Serotonin is a vital neurotransmitter whose exact roles are ill-defined. Dysfunctions in serotonin signaling are thought to underlie a myriad of neurological problems including depression and autism spectrum disorder (ASD). Prior to investigating serotonin’s role in disease states, one must understand more about the functionality of serotonin in healthy in vivo models. To study serotonin in vivo, fast-scan cyclic voltammetry (FSCV) and fast- scan controlled adsorption voltammetry (FSCAV) are employed to measure evoked and basal serotonin concentration, respectively. These methods, combined with mathematical modeling, provide information regarding regulatory mechanisms of serotonin neurotransmission. FSCV and FSCAV are first applied to …

Titration Of A Newtown Creek Environmental Water Sample To Determine The Amount Of Chloride Ions [Chemistry], Kevin Mark

Open Educational Resources

Main Course Learning Objectives:

The General Chemistry 1 (SCC 201) course has multiple course learning objectives, which articulate key introductory chemistry concepts that all STEM students should possess. In particular, the Newtown Creek titration experiment aligns with SCC 201 learning objectives of:

1. Demonstrate an appreciation of the role of chemistry in various aspects of life
2. Perform basic laboratory skills such as the proper execution of titration techniques
3. Describe and explain the fundamental chemistry concept of solution concentration
4. Analyze and represent experimental data in tables and graphs, interpret experimental results and write laboratory reports

In the SCC 201 laboratory, students are …

Microwave Solventless Synthesis Of Meso-Tetrakis (Pentafluorophenyl)Poprphyrin (Tppf20) And Tris(Pentafluorophenyl))Corrole [Chemistry], Sunaina Singh

Open Educational Resources

Organic chemistry is a two-semester course (Organic Chemistry I, SCC 251 and Organic Chemistry II, SCC 252) required for majors in Biology. The SCC 251 course has been designated for the Integrative Learning Core Competency as well the Digital Communication Ability. This course emphasizes the synthesis, structure, reactivity, and mechanisms of reaction of organic compounds. Laboratory stresses various organic synthetic and analytic techniques (distillation, extraction, chromatography and spectroscopy).

This lab provided an opportunity for students to go deeper with the chemistry content by correlating to the concepts they learned in General Chemistry courses such as Valence shell electron pair repulsion …

State-To-State Inelastic Rotational Cross Sections In Five-Atom Systems With The Multiconfiguration Time Dependent Hartree Method, Steve Ndengue, Yohann Scribano, Fabien Gatti, Richard Dawes

Chemistry Faculty Research & Creative Works

We present a MultiConfiguration Time Dependent Hartree (MCTDH) method as an attractive alternative approach to the usual quantum close-coupling method that approaches some computational limits in the calculation of rotational excitation (and de-excitation) between polyatomic molecules (here collisions between triatomic and diatomic rigid molecules). We have performed a computational investigation of the rotational (de-)excitation of the benchmark rigid rotor H₂O-H₂ system on a recently developed Potential Energy Surface of the complex using the MCTDH method. We focus here on excitations and de-excitations from the 0₀₀, 1₁₁, and 1₁₀ states of H_{2 …}

Preparation And Detailed X-Ray Photoelectron Spectroscopy And Spectroscopic Ellipsometryanalysis Of Ultrathin Protective Coatings, Brian Ivins Johnson

Theses and Dissertations

Ultra-thin films (UTFs) are important in many applications, seen in the semiconductor industry, in chromatography, in sensing, in microfluidics, in aerospace, and in robotics. They also protect materials from corrosion, change surface energies, limit water intrusion into materials, allow material self-cleaning and self-healing, provide scratch resistance, and impart other specific chemical properties. In many cases, UTFs drastically alter surface properties and therefore their applications. It is imperative that proper and consistent characterization be performed on coatings to confirm and understand their desired properties. In Chapter two, Al oxidation under MgF2 protective layers is studied using real time X-ray photoelectron spectroscopy …

Self-Assembly And Emergent Properties Of Urea Tethered Triphenylamines For The Formation Of Regenerable Radicals, Ammon J. Sindt

Theses and Dissertations

Self-assembly of photoactive compounds in the solid-state can give rise to new photophysical properties. Key to these properties, is how these compounds can be organized in a uniform way. For this, hydrogen bonding building blocks can be used to guide the assembly of these compounds into organized structures. For instance, ureas, thioureas, and squaramides which contain both hydrogen bond donors and acceptors can guide the assembly of small m-xylene macrocycles in three distinct manners: 1-D columns, edge-to-face Herringbone patterns, and interdigitated networks. The former of these is commonly employed in our group to make either linear or macrocyclic dimers …

Heterogeneous Ozonation Of Model Drinking Water Contaminants Using Cbv-720 Zeolite, Benson Maxwell Solomon

Theses and Dissertations

Advanced Oxidation Processes (AOPs) are designed to remove aqueous organic contaminants through their reaction with hydroxyl radicals (HO∙). Ozone is classified as an AOP due to its ability to produce hydroxyl radicals, as well as its ability to oxidize a wide range of organic contaminants. Due to the unselective nature of hydroxyl radicals, many organic and inorganic co-solutes can act as scavengers, reducing the efficiency of an AOP. Here we show a probe system for testing the hypothesis that adsorptive ozonation of contaminants may yield a more selective environment that favors neutral contaminant oxidation over oxidation of co-solutes.

Initial experiments …

Iodane-Guided C-H Cleavage To Synthesize Densely Functionalized Arenes, Aleksandra Nilova, Paul A. Sibbald, Edward J. Valente, Gisela Gonzalez-Monteil, H. Camille Richardson, Kevin S. Brown, Paul Cheong, David Stuart

Chemistry Faculty Publications and Presentations

We describe a strategy for the iodane-guided functionalization of sterically congested C-H bonds, which is distinct from electronic, steric or proximity guided C-H functionalization methods. Readily accessible aryl(Mes)iodonium salts serve as the starting materials in these reactions and produce complex 1,2,3,4-substituted arenes via aryne intermediates. This approach is especially powerful when coupled with the innate C-H functionalization reactivity of simple arenes, to replace two C-H bonds with two C-C or C-heteroatom bonds while over-riding steric effects that typically inhibit such reactions. DFT stud-ies reveal a contribution of inductive, resonance, and steric effects on the regioselectivity of C-H cleavage and aryne …

Visible And Ultraviolet Upconversion And Near Infrared Downconversion Luminescence From Lanthanide Doped La2zr2o7 Nanoparticles, Santosh K. Gupta, Mitzy A. Penilla Garcia, Jose P. Zuniga, Maya Abdou, Yuanbing Mao

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

Single materials which have a multitude of photophysical processes by selective doping are in high demand in the community of material science due to their multifunctional applications. Upconversion (UC) and downconversion (DC) luminescence properties of lanthanide doped nanoparticles (NPs) are imperative for their broad application potentials. Here, we describe two series of either doubly or triply doped La2Zr2O7 NPs synthesized by a molten salt method. For the former, La2Zr2O7:Yb,Er NPs display bright red and moderate green UC (VUC) and NIR-B DC (NDC) at around 1550 nm, which are highly desirable for in-vivo bioimaging applications. For the latter, La2Zr2O7:Gd,Yb,Tm NPs demonstrate …

Improving Thorium-230 Determination In Marine Sediment, Katherine Mateos

Independent Study Project (ISP) Collection

Our oceans are intimately related to the climate of our planet. Paleoceanographic approaches aim to study oceans through geologic time to improve models of future climate. Radioisotopes provide us with chemical tracers that help us understand change through time. The uraniumseries decay chain contains thorium-230, a decay product of uranium-234. This isotope is useful to paleoceanographers in its disequilibrium to its parent isotope and in determining the flux of sediment falling to the ocean floor. In order to use 230Th to study oceans, we must be able to accurately measure the amount of thorium in sediment samples. Thorium is found …

Synthesis And Characterization Of Hyaluronic Acid Based Biomaterials For Drug Delivery And Virus Modification, Amanda Wagner

Theses and Dissertations

In this thesis, hyaluronic acid based biomaterials are studied. The properties and potential applications of these polymers are characterized and discussed.

In Chapter 1, biomaterials are introduced as well as hydrogels and nanogels. Hyaluronic acid is highlighted as a remarkable bio-polymer. The overall objectives of my research are also discussed.

Chapter 2 is focused around trials for utilizing graphene oxide as a nanomaterial for controlling the drug release of an aromatic compound. Hyaluronic acid based hydrogels were synthesized as a delivery vessel. The results of the drug release profiles are examined and discussed.

A different direction is taken in Chapter …

Studies Of Ch Activation In Unsaturated Amides And Esters By Trinuclear Metal Carbonyl Clusters Of Osmium, Morteza Maleki

Theses and Dissertations

The chemistry of the reaction of Os3(CO)10(NCCH3)2 with representatives of unsaturated amides and esters, RCOCHCH2 (R=(CH3)2N, CH3O) has been investigated. In these reactions, it has been observed that a CH bond on the β-carbon atom is readily activated by triosmium carbonyl clusters. The activation of β-carbon C-H bond in unsaturated amides and esters provides a robust platform for studying multicenter C-H bond transformations and for C-C bond formation via hydrogen shift and CO insertion processes. In this work, proposed mechanistic approaches have been taken in order to better understand and study the relationship between the characterized species. In addition, a …