Other Chemistry Commons^™

Vibrational Analysis Of A Rate-Slowing Conformational Kinetic Isotope Effect, O. Maduka Ogba, Zichen Liu, Daniel J. O'Leary

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

An enthalpy-entropy approach to analyzing a rate-slowing conformational kinetic isotope effect (CKIE) in a deuterated doubly-bridged biaryl system is described. The computed isotope effect (kH/kD = 1.075, 368 K) agrees well with the measured value (kH/kD = 1.06, 368 K). The rateslowing (normal isotope effect) nature of the computed CKIE is shown to originate from a vibrational entropy contribution defined by the twenty lowest frequency normal modes in the ground state and transition state structures. This normal entropy contribution is offset by an inverse vibrational enthalpy contribution, which also arises from the twenty lowest frequency normal modes. Zero point vibrational …

Atom-Specific Activation In Co Oxidation, Simon Schreck, Elias Diesen, Jerry Larue, Hirohito Ogasawara, Kess Marks, Dennis Nordlund, Matthew Weston, Martin Beye, Filippo Cavalca, Fivos Perakis, Jonas Sellberg, André Eilert, Kyung Hwan Kim, Giacomo Coslovich, Ryan Coffee, Jacek Krzywinski, Alex Reid, Stefan Moeller, Alberto Lutman, Henrik Öström, Lars G. M. Pettersson, Anders Nilsson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report on atom-specific activation of CO oxidation on Ru(0001) via resonant X-ray excitation. We show that resonant 1s core-level excitation of atomically adsorbed oxygen in the co-adsorbed phase of CO and oxygen directly drives CO oxidation. We separate this direct resonant channel from indirectly driven oxidation via X-ray induced substrate heating. Based on density functional theory calculations, we identify the valence-excited state created by the Auger decay as the driving electronic state for direct CO oxidation. We utilized the fresh-slice multi-pulse mode at the Linac Coherent Light Source that provided time-overlapped and 30 fs delayed pairs of soft …

Stabilized, Hybrid Solid-State Photocatalysts For Water Purification: Preparation, Properties And Performance Under Visible Light Irradiation, Karpagavalli Ramji

Seton Hall University Dissertations and Theses (ETDs)

Stabilized heterogeneous photocatalysts that use only solar light and air have been prepared and successfully employed to decontaminate water from organic pollutants. Organic dye pollutants present, for example in textile effluents, are one of the major sources of water pollution owing to their limited biodegradability, toxicity and potential carcinogenic risks. Before certifying water for public consumption, reuse in industries or for discharge in surface water the organic pollutants must be degraded, an effort that is energy intensive and currently requires complex methodologies. We report solid-state photocatalysts that use only visible light and air to treat wastewater. Perfluoroalkyl perfluoro-substituted zinc phthalocyanine …

Syntheses Of A Tin (Iv) Meso-Tetra(4-Pyridyl) Porphyrin Dichloride-Tetrachlorobis (Bipy)2 Ruthenium (Ii) Complex And Studies Of Photophysical Properties Of 1-Nitropyrene, Phillip Sharp

Electronic Theses and Dissertations

Development of a photosensitizer that can work in both aerobic and anaerobic environments would increase the robustness of the cancer treatment known as photodynamic therapy. The development of a photosensitizer was first attempted by synthesizing a tin (IV) meso-tetra (4-pyridyl) porphyrin dichloride-tetrachlorobis (Bipy)₂ ruthenium (II) complex. The synthesize of the tin porphyrin was done by a method from literature and had a percent error of 31.58 and 37.31 when comparing the theoretical percentages of carbon (55.39) and nitrogen (12.92) meaning that photosensitizer was not synthesized.

The second type of chromophore that was studied was 1-nitropyrene do determine if it …

Nanoparticles And Their Use In Cancer Imaging, Prevention And Treatment, George Gray

Chemistry & Biochemistry Student Projects

No abstract provided.

Tomatine And Furocoumarins: Toxins In Commonly Consumed Plants, Julia Noonan

Chemistry & Biochemistry Student Projects

No abstract provided.

1h And 13c Nmr Assignments For (N-Methyl)-(−)-(Α)-Isosparteinium Iodide And (N-Methyl)-(−)-Sparteinium Iodide, Kavoos Kolahdouzan, O. Maduka Ogba, Daniel J. O'Leary

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

(‒)-Sparteine (1) and (–)-(α)-isosparteine (2) are members of the lupine alkaloid family.^[1-2] Sparteine has found extensive use in asymmetric organic transformations, including lithiations^[3] and Pd-catalyzed oxidations.^[4-7] (α)-Isosparteine, which can be made from sparteine, has been utilized as a chiral ligand for a limited number of stereoselective reactions.^[8-9] The two compounds differ in that 1 displays an exo-endo arrangement of the bridgehead hydrogens at C-11 and C-6, respectively, while 2 retains an exo-exo arrangement of these atoms (Figure 1). This study is focused on assigning 1H chemical shifts and coupling constants and 13C chemical shifts for N-methyl …

Development Of Chemistry Activities For Local Outreach In Stem, Emily Knight

Chemistry & Biochemistry Student Projects

Introduction: This research project was started because of an increase in outreach opportunities for the Department of Chemistry and Biochemistry. For similar opportunities, we now have bins of content that are simple to use, encouraging more students to participate in volunteer research.

Purpose: to find, modify, and/or create grade-level appropriate labs and demonstration activities for 5th-8th graders, with a specific focus on activities hat involve easily available components. These activities are intended to be used for outreach to local schools by chemistry student volunteers and released online to act as a resource for teachers.

Educational Resources: Polymers, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

This document contains 3 polymer-based activities demonstrating different properties of polymers - the physical characteristics, possible absorbency, and elasticity. These activities can be abbreviated and used in rotating stations, planned over multiple days, or you can pick on that fits best with the classroom environment.

Educational Resources: Ionic Matching, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

The entire point of this piece is simply to introduce balancing charges in ionic compounds. This is a simpler method to get students thinking about the idea, which also makes it suitable for pre-high school students. It gives a visual representation of how charges balance and cow cations pair with anions. At this level, it is very similar to least common denominator calculations.

Educational Resources: Homemade Fluorometer, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

Educational Resources: Exchange Rates And Unit Conversion, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

Students might have experience in 3rd-6th grade with converting basic ideas such as volume and measurements. This is intended to expand that idea and introduce the mole. It's also a general interactive conversion/exchange activity. All items in here are just based on what we had available and convenient, so feel free to swap out items such as rubber stoppers with something more easily available …

Educational Resources: Curie Point Engine, Emily Knight

Chemistry & Biochemistry Student Projects

The document is meant to act as a resource for elementary through middle school teachers, featuring a science activity connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.

The Curie point of a metal is the temperature at which it loses its magnetic characteristics. Heat can cause magnets to stop being magnetic, which is why heating up magnets is not advised. The engine works because the Curie point of nickel is 354 degrees Celsius, a temperature that can be reached with a simple candle flame. Included are instructions about how to build …

Educational Resources: Magnets, Emily Knight

Chemistry & Biochemistry Student Projects

No abstract provided.

Secondary Electronic And Solvent Effects On Regiospecific P-Bromination Of Aromatic Systems, Selahaddin Gumus

Masters Theses & Specialist Projects

Bromoarenes are important aromatic building blocks that are commonly used to synthesize various functional compounds in pharmaceutical, agrochemical and related industries.^1,2 This great demand for bromoarenes makes their preparation a widely studied area of synthetic organic chemistry. However, further understanding of the reactivity and regiochemistry of aromatic functionalization reactions is still necessary, as much about the secondary substitution and solvent effects remain unknown.

Resonance Theory is a widely used theoretical model to predict the regiospecifity and reactivity of the bromination of various aromatic compounds.³ The reactivity and regiospecificity of many substituted aromatic compounds is well explained using resonance …

Organic Photochemistry: Remote Delivery Of Reactive Oxygen Intermediates Via A Heterogeneous Approach, Niluksha Walalawela Abeykoon

Dissertations, Theses, and Capstone Projects

Photosensitized oxidation reactions produce a number of intermediates species, which are generated in varying amounts over time. This complexity presents major challenges in the study of oxidation processes. Mechanistic efforts to separate and deliver reactive oxygen intermediates enable their controlled use in processes such as bacterial inactivation. This thesis describes a heterogeneous reaction approach taken to control the generation and delivery of reactive oxygen intermediates. The mechanistic details of photosensitized reactions were elucidated via synthetic, materials, and physical organic techniques to optimize the delivery of reactive oxygen intermediates. This thesis contains six chapters as described below.

Chapter 1 gives a …

Experiential Learning Activity: Biodiesel Inquiry Project, Ji Kim

Open Educational Resources

The activity described herein can be implemented in introductory chemistry and high school chemistry courses. The main goal of the project is to integrate a ubiquitous biodiesel production with experiential learning by providing a community-based project. The students work in groups, research the benefits of using biodiesel over petroleum-based diesel, collect waste cooking oil from home or restaurants, develop simple and cost-effective methods to produce biodiesel.

Palladium-Catalyzed Carbonyl Allylation Reactions Using Tin Chloride: A Mini-Review, Armando M. Guidote Jr, Mikael John A. Baltazar, Roy Kristian C. Yanela, Noriyuki Suzuki

Chemistry Faculty Publications

The treatment of allylic alcohols as synthons of carbanions for carbonyl allylation reactions in the presence of a Pd-SnCl2 system has been one of the most interesting and most useful developments demonstrated by Yoshiro Masuyama and co-workers in the field of organic synthesis. The reaction makes use of palladium as an effective catalyst and tin (II) chloride as a low-valent reducing agent which also effectively transforms the allylic group to a nucleophilic group. The organic, as well as organometallic, chemistry of how the transformations occur and how the metals take part in the reaction is of great interest. These could …

Gas-Phase Studies Of Nucleophilic Substitution Reactions: Halogenating And Dehalogenating Aromatic Heterocycles, Leah L. Donham

Theses and Dissertations

Halogenated heterocycles are common in pharmaceutical and natural products and there is a need to develop a better understanding of processes used to synthesize them. Although the halogenation of simple aromatic molecules is well understood, the mechanisms behind the halogenation of aromatic heterocycles have been more problematic to elucidate because multiple pathways are possible. Recently, new, radical-based mechanisms have been proposed for heterocycle halogenation. In this study, we examine and test the viability of possible nucleophilic substitution, S_N2@X, mechanisms in the halogenation of anions derived from the deprotonation of aromatic heterocycles. All the experiments were done in a …

No Evidence For Trace Metal Limitation On Anaerobic Carbon Mineralization In Three Peatland Soils, Jason K. Keller, Jillian Wade

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands store roughly one-third of the terrestrial soil carbon and release the potent greenhouse gas methane (CH₄) to the atmosphere, making these wetlands among the most important ecosystems in the global carbon cycle. Despite their importance, the controls of anaerobic decomposition of organic matter to carbon dioxide (CO₂) and CH₄ within peatlands are not well understood. It is known, however, that the enzymes responsible for CH₄ production require cobalt, iron and nickel, and there is a growing appreciation for the potential role of trace metal limitation in anaerobic decomposition. To explore the possibility of …

Ensemble-Based Modeling And Rigidity Decomposition Of Allosteric Interaction Networks And Communication Pathways In Cyclin-Dependent Kinases: Differentiating Kinase Clients Of The Hsp90-Cdc37 Chaperone, Gabrielle Stetz, Amanda Tse, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

The overarching goal of delineating molecular principles underlying differentiation of protein kinase clients and chaperone-based modulation of kinase activity is fundamental to understanding activity of many oncogenic kinases that require chaperoning of Hsp70 and Hsp90 systems to attain a functionally competent active form. Despite structural similarities and common activation mechanisms shared by cyclin-dependent kinase (CDK) proteins, members of this family can exhibit vastly different chaperone preferences. The molecular determinants underlying chaperone dependencies of protein kinases are not fully understood as structurally similar kinases may often elicit distinct regulatory responses to the chaperone. The regulatory divergences observed for members of CDK …

Ab Initio Methyl Linoleate Bond Dissociation Energies: First Principles Fishing For Wise Crack Products, Zachary Ryan Wilson

Graduate Theses/Dissertations

With the prices of petroleum reflecting demand for this finite resource, attention has been turned to alternative sources of energy. Biodiesel, defined as fatty acid methyl esters (FAMEs), exhibits many of the same properties as conventional diesel but is derived from biological sources. FAMEs are subsequently thermally cracked to form more light-weight petrochemical products. I aim to further understand the thermal cracking procedure, at an atomic-level, in hopes that this may aid in future engineering of viable fuels. I studied the effective computational modeling of bond disassociations in the FAME methyl linoleate. Bond dissociation in a 44-reaction database with known …

Cellular And Molecular Targets Of Menthol Actions, Murat Oz, Eslam El Nebrisi, Keun-Hang Susan Yang, Frank Christopher Howarth, Lina T. Al Kury

Mathematics, Physics, and Computer Science Faculty Articles and Research

Menthol belongs to monoterpene class of a structurally diverse group of phytochemicals found in plant-derived essential oils. Menthol is widely used in pharmaceuticals, confectionary, oral hygiene products, pesticides, cosmetics, and as a flavoring agent. In addition, menthol is known to have antioxidant, anti-inflammatory, and analgesic effects. Recently, there has been renewed awareness in comprehending the biological and pharmacological effects of menthol. TRP channels have been demonstrated to mediate the cooling actions ofmenthol. There has been new evidence demonstrating thatmenthol can significantly influence the functional characteristics of a number of different kinds of ligand and voltage-gated ion channels, indicating that at …

The Quantification Of Cocaine From The Erythroxylum Coca Plant And The Comparison On High Performance Liquid Chromatography And Gas Chromatography Mass Spectroscopy As An Analytical Method., Tuesday James

Student Theses

Cocaine is derived from the Erythroxylum coca plant, is a highly addictive stimulant abused all over the world. There are two types of Erythroxylum coca plants that produce cocaine; the E. Coca and E. Novogranatense. Cocaine exists as the salt, and the freebase which is typically referred to as “crack” due to the crackling sound it makes when heated. It is popular because it is inexpensive and easily available on the streets, mainly in poor urban areas. The purpose of this project was to determine the amount of cocaine that can be extracted from E.coca and to assess which analytical …

From The Making To The Tuning To The Use Of Chlorins For Biomedical Applications, Junior Gonzales

Dissertations, Theses, and Capstone Projects

Chlorins are porphyrins missing a double bond. These pigments are optimal platforms for the development of novel dyes that display drug-like attributes such as photodynamic therapy (PDT) agents. More recently, it was demonstrated that chlorins can serve both as a PDT agent and as a modality for fluorescence or PET imaging. Thus, multifunctional chlorins eliminate the differences that may occur in specificity, uptake, and distribution between separate compounds or constructs for imaging and therapy. The overall goal of this dissertation is to take advantage of the reputed intrinsic attributes of chlorins as a viable tool in biomedical applications. In this …

Conservative Tryptophan Mutations In Protein Tyrosine Phosphatase Ptp1b And Its Effect On Catalytic Rate And Chemical Reaction, Teisha Richan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein-tyrosine phosphatases (PTPs) catalyze the hydrolysis of phosphorylated tyrosines by a 2-step mechanism involving nucleophilic attack by cysteine and general acid catalysis by aspartic acid. In most PTPs the aspartic acid resides on a flexible protein loop, consisting of about a dozen residues, called the WPD loop. PTP catalysis rates span several orders of magnitude, and differences in WPD loop dynamics have recently been show to correlate with the rate of enzymatic catalysis. The rate of WPD loop motion could possibly be related to a widely conserved tryptophan residue on the WPD loop. Therefore, point mutants were made in PTP1B …

Approaches Toward Novel 1,2,3-Triazole Sensors For The Detection Of Anions And Heavy Metal Cations, Richard D. Govan

College of Graduate Studies: Theses & Dissertations

Cations and anions play pivotal roles in biological and physiological processes, however an imbalance in concentration of any ion can be detrimental. Therefore, research into the selective recognition of anions and heavy metal cations has acquired much attention. One approach involves the use of chemosensors. Upon interaction with targeted analytes, chemosensors produce a distinct response, in some cases a fluorescent or colorimetric signal. The 1,2,3-triazole unit has much potential as a chemical sensor due to its unique photophysical properties. The specificity, selectivity, and signaling mechanism of triazole sensors can be tuned with conjugation in the motif and choice and placement …

The Synthesis Of Chemosensors For Toxic Analytes, Johnathan Hugh Broome

Dissertations

A number of chemosensors have been designed and synthesized to target cations (Zn²⁺ions), neutral molecules (cathinones), charged molecules (aminoindanes), and anions. The Zn²⁺ ion sensor featured bistriazole designed binding unit and ferrocene signaling units. Characterization of Zn²⁺ ion binding was carried out with electrochemical techniques (CV and DPV), ¹H-NMR, mass spectrometry, and molecular modelling. It exhibited a 1:1 binding stoichiometry with Zn²⁺ and had an affinity for ZnCl₂ (Log K_1:1 = 4.1 ± 0.02) over other Zn²⁺ salts.

The cathinone probe was designed to selectively bind mephedrone over common street drugs …

Mida Boronates Are Hydrolysed Fast And Slow By Two Different Mechanisms, Jorge A. Gonzalez, O. Maduka Ogba, Gregory F. Morehouse, Nicholas Rosson, Kendall N. Houk, Andrew G. Leach, Paul H.-Y. Cheong, Martin D. Burke, Guy C. Lloyd-Jones

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

MIDA boronates (N-methylimidodiacetic boronic acid esters) serve as an increasingly general platform for building-block-based small molecule construction, largely due to the dramatic and general rate differences with which they are hydrolysed under various basic conditions. Yet the mechanistic underpinnings of these rate differences have remained unclear, hindering efforts to address current limitations of this chemistry. Here we show that there are two distinct mechanisms for this hydrolysis: one is base-mediated and the other neutral. The former can proceed more than three orders of magnitude faster, and involves rate-limiting attack at a MIDA carbonyl carbon by hydroxide. The alternative ‘neutral’ hydrolysis …

Theoretical Investigation Of Interaction Between The Set Of Ligands And Α7 Nicotinic Acetylcholine Receptor, O. E. Glukhova, Tatiana Prytkova, D. S. Shmygin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nicotinic acetylcholine receptors (nAChRs) are neuron receptor proteins that provide a transmission of nerve impulse through the synapses. They are composed of a pentametric assembly of five homologous subunits (5 α7 subunits for α7nAChR, for example), oriented around the central pore. These receptors might be found in the chemical synapses of central and peripheral nervous system, and also in the neuromuscular synapses. Transmembrane domain of the one of such receptors constitutes ion channel. The conductive properties of ion channel strongly depend on the receptor conformation changes in the response of binding with some molecule, f.e. acetylcholine. Investigation of interaction between …