Chemistry Commons^™

Functionality Of Membrane Proteins Overexpressed And Purified From E. Coli Is Highly Dependent Upon The Strain, Khadija Mathieu, Waqas Javed, Sylvain Vallet, Christian Lesterlin, Marie-Pierre Candusso, Feng Ding, Xiaohong Nancy Xu, Christine Ebel, Jean-Michel Jault, Cédric Orelle

Chemistry & Biochemistry Faculty Publications

Overexpression of correctly folded membrane proteins is a fundamental prerequisite for functional and structural studies. One of the most commonly used expression systems for the production of membrane proteins is Escherichia coli. While misfolded proteins typically aggregate and form inclusions bodies, membrane proteins that are addressed to the membrane and extractable by detergents are generally assumed to be properly folded. Accordingly, GFP fusion strategy is often used as a fluorescent proxy to monitor their expression and folding quality. Here we investigated the functionality of two different multidrug ABC transporters, the homodimer BmrA from Bacillus subtilis and the heterodimer PatA/PatB …

Recent Trends In Stratospheric Chlorine From Very Short‐Lived Substances, Ryan Hossaini, Elliot Atlas, Sandip S. Dhomse, Martyn P. Chipperfield, Peter F. Bernath, Anton M. Fernando, Jens Mühle, Amber A. Leeson, Stephen A. Montzka, Wuhu Feng

Chemistry & Biochemistry Faculty Publications

Very short‐lived substances (VSLS), including dichloromethane (CH₂Cl₂), chloroform (CHCl₃), perchloroethylene (C₂Cl₄), and 1,2‐dichloroethane (C₂H₄Cl₂), are a stratospheric chlorine source and therefore contribute to ozone depletion. We quantify stratospheric chlorine trends from these VSLS (VSLCl_tot) using a chemical transport model and atmospheric measurements, including novel high‐altitude aircraft data from the NASA VIRGAS (2015) and POSIDON (2016) missions. We estimate VSLCl_tot increased from 69 (±14) parts per trillion (ppt) Cl in 2000 to 111 (±22) ppt Cl in 2017, with >80% delivered to …

Exomol Line List - Xxxiv. A Rovibrational Line List For Phosphinidene (Ph) In Its X³Σ¯ And A¹Δ Electronic States, Jonathan Langleben, Jonathan Tennyson, Sergei N. Yurchenko, Peter Bernath

Chemistry & Biochemistry Faculty Publications

A rovibronic line list for the ground (X³Σ⁻) and first excited (a¹Δ) states of phosphinidene, ³¹PH, is computed. The line list is designed for studies of exoplanetary and cool stellar atmospheres with temperatures up to 4000 K. A combination of empirical and ab initio data is used to produce the line list: potential energy curves (PECs) are fitted using experimental transition frequencies; these transitions are reproduced with a root mean square error of 0.01 cm⁻¹. The nuclear Schrödinger equation is solved using these PECs plus Born–Oppenheimer and spin splitting correction terms. …

Shelf Inputs And Lateral Transport Of Mn, Co, And Ce In The Western North Pacific Ocean, Peter L. Morton, William M. Landing, Alan M. Shiller, Amy Moody, Thomas D. Kelly, Michael Bizimis, John R. Donat, Eric H. De Carlo, Joseph Shacat

Chemistry & Biochemistry Faculty Publications

The margin of the western North Pacific Ocean releases redox-active elements like Mn, Co, and Ce into the water column to undergo further transformation through oxide formation, scavenging, and reductive dissolution. Near the margin, the upper ocean waters enriched in these elements are characterized by high dissolved oxygen, low salinity, and low temperature, and are a source of the North Pacific Intermediate Water. High dissolved concentrations are observed across the Western Subarctic Gyre, with a rapid decrease in concentrations away from the margin and across the subarctic-subtropical front. The particulate concentrations of Mn, Co, and Ce are also high in …

Molecular Level Comparison Of Water Extractives Of Maple And Oak With Negative And Positive Ion Esi Ft-Icr Mass Spectrometry, Zhongqi He, Rachel L. Sleighter, Patrick G. Hatcher, Shasha Liu, Fengchang Wu, Haixuan Zou, O. Modesto Olanya

Chemistry & Biochemistry Faculty Publications

Soluble extractives in wood function to protect living trees from destructive agents and also contribute to wood color and fragrance. Some extractive components have biological activities with medical applications. They also play important roles in wood processing and related applications. To increase the knowledge of wood chemistry, maple and oak were extracted by water. Ultraviolet/visible (UV/vis) spectroscopy indicated the presence of a phenolic compound, resorcinol, in maple extractives having higher molecular mass and more aromatic components than oak extractives. Negative and positive electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS) identified thousands of formulas in the two …

Compositions And Structures Of Particulate And Colloidal Organic Matter In Aquatic Environment By Advanced Analytical Techniques, Yong Ran, Dainan Zhang, Shujie Hu, Yu Yang, Jingdong Mao

Chemistry & Biochemistry Faculty Publications

Dissolved, colloidal and particulate organic matter (DOM, COM and POM) is important in the global carbon cycle and knowledge of their sources and structures can be critical to understanding their roles in biogeochemical cycles. This study explored the sources and chemical structures of COM and POM samples from the Pearl River Basin, China by elemental, chlorophyll a (Chl a), radiocarbon and stable carbon isotopic analyses, NMR techniques, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis. The chemical and nano-sclae structures of two ultrafiltered dissolved organic matter (UDOM) samples from surface seawater of the Pacific and Atlantic Ocean …

Condensation And Polymerization Explain The Humification Of Lignin Into Aliphatic And Aromatic Structures In Soil, Patrick G. Hatcher, Hongmei Chen, Seyyedhadi Khatami, Derek C. Waggoner

Chemistry & Biochemistry Faculty Publications

Soil organic matter (SOM) constitutes a global reservoir of carbon that is more than twice that of either atmospheric carbon or aquatic carbon; however, the manner in which it forms from degraded plant biomass is poorly understood. Some have recently questioned whether plant biomass is involved directly in SOM formation and suggest that it is microbial carbon that constitutes the main source of stable SOM. Such a view implies that above and below ground plant biomass is rapidly decomposed and mineralized. This view contrasts significantly with traditional ones that involve the transformation of plant biomass to recalcitrant humic materials fueled …

Phosgene In The Upper Troposphere And Lower Stratosphere: A Marker For Product Gas Injection Due To Chlorine-Containing Very Short Lived Substances, Jeremy J. Harrison, Martyn P. Chipperfield, Ryan Hossaini, Christopher D. Boone, Sandip Dhomse, Wuhu Feng, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Abstract: Phosgene in the atmosphere is produced via the degradation of carbon tetrachloride, methyl chloroform, and a number of chlorine‐containing very short lived substances (VSLS). These VSLS are not regulated by the Montreal Protocol even though they contribute to stratospheric ozone depletion. While observations of VSLS can quantify direct stratospheric source gas injection, observations of phosgene in the upper troposphere/lower stratosphere can be used as a marker of product gas injection of chlorine‐containing VSLS. In this work we report upper troposphere/lower stratosphere measurements of phosgene made by the ACE‐FTS (Atmospheric Chemistry Experiment Fourier Transform Spectrometer) instrument and compare with results …

Analytical Chemistry 2.1, David T. Harvey

Chemistry & Biochemistry Faculty Publications

The introductory course in analytical chemistry is the ideal place in the undergraduate chemistry curriculum for exploring topics such as experimental design, sampling, calibration strategies, standardization, optimization, statistics, and the validation of experimental results. Analytical methods come and go, but best practices for designing and validating analytical methods are universal. Because chemistry is an experimental science it is essential that all chemistry students understand the importance of making good measurements.

Spatial Patterns Of Particulate Organic Carbon Concentrations And Isotopic Signatures Across A Salinity Gradient In A River Dominated Estuary, Lauren E. Alvaro, John C. Lehrter, Mai Fung

Gulf and Caribbean Research

No abstract provided.

The Synthesis Of Ferrocene-Based Ionic Liquids, Stephen Petrochko

Williams Honors College, Honors Research Projects

Ionic liquids are compounds which are held together through ionic interactions, and can be classified as salts. However, while most salts have very high melting temperatures, ionic liquids are a class of compounds that can melt at very low temperatures, often at room temperatures. Ionic liquids can have optimal electronic properties for electrochemical applications, particularly for the easy transport of charges. Some new materials are being explored for the development of ionic liquids; one of these materials is ferrocene. Varying the substituents which are attached to ferrocene may produce a material that can be used as an electrolyte in energy …

Facial Rhenium Tricarbonyl Complexes With Modified Dii Ligands, Dominick Vitale

Williams Honors College, Honors Research Projects

Over the course of this semester, promising preliminary research into a novel area of inorganic chemistry has been underway. Multiple different bis(arylimino)isoindolines (BAI), a compound made from the disubstitution of diiminoisoindoline with aryl amines to form planar tridentate ligands, were tested to determine if the structure could be forcefully bent to fit a facial binding mode. It was theorized that the bending of the usually planar chelate would cause an electronic change, destabilizing the orbitals. Different synthetic techniques were explored allowing the formation a new BAI, 1,3-bis(3-pyrazolylimino)isoindoline which was characterized via X-ray crystallography, as well as a few previously characterized …

Electronic Tuning Of Dimolybdenum Complexes Through Symmetry Manipulation Of Formamidinate Ligands In Their Second Coordination Sphere, Iván Alonso Cervantes Cervantes Martã­Nez

Open Access Theses & Dissertations

Alternative sustainable energy sources are required to decrease our dependence on carbon-based fuels. Small molecule activation is one of the most promising to fulfill global energy demand and maintain a sustainable world. Most of the industrial processes relevant for global energy supply and expenditure involves small molecules and metal catalysts. However, it is still required to gain fundamental insights on how these catalysts achieve such reactions. Dinuclear compounds, namely dimolybdenum complexes, may serve as a good experimental model to understand metal-metal cooperativity and its influence in catalysis.

In Chapter 2, three unsymmetric aryl formamidines were synthesized and characterized through 1H …

Application Of Urinary Metabolites For Cancer Detection, Qin Gao

Open Access Theses & Dissertations

Prostate cancer (PCa) is the 3rd most common cause of male cancer mortality in the US. Early diagnosis and treatment of PCa will improve the quality of care and reduce mortality. The prostate specific antigen (PSA) is commonly used in the current PCa screening, but its limitation has resulted in an intense search for more reliable biomarkers. Studies showed that dogs could differentiate PCa patients from negative control by sniffing their urine. As the odor profiles are generated by volatile organic compounds (VOCs), the finding suggests that particular VOCs could be linked to PCa, PCa risk levels and other cancers. …

Synthesis Of Advanced Functional Nanomaterials For Sustainable Water Treatment Technologies, Md Tariqul Islam

Open Access Theses & Dissertations

Water is the most essential resource for the sustenance of life. Water is also necessary for agriculture, industry, household, and environmental conservation. However, due to large population growth and industrial expansion, access to clean water is becoming increasingly difficult around the world. Current water treatment technologies have not changed in over one hundred years and require a large infrastructure due to their low efficiencies and large-scale needs. In this context, the utilization of advanced functional nanomaterials and the adaptation of nanotechnology could potentially allow for miniaturizing water treatment and develop de-centralized solutions for rural areas. This Dissertation presents the design, …

(E)-6,6′-(Diazene-1,2-Di­Yl)Bis­(1,10-Phenanthrolin-5-Ol) Tri­Chloro­Methane Disolvate: A Superconjugated Ligand, Muhib Ahmed, Michael Devereux, Vickie Mckee, Malachy Mccann, A. Denise Rooney

Articles

Phenanthroline ligands are important metal-binding mol­ecules which have been extensively researched for applications in both material science and medicinal chemistry. Azo­benzene and its derivatives have received significant attention because of their ability to be reversibly switched between the E and Z forms and so could have applications in optical memory and logic devices or as mol­ecular machines. Herein we report the formation and crystal structure of a highly unusual novel diazo-diphenanthroline compound, C24H14N6O2·2CHCl3.

Ibuprofen As A Probe Of Lipid Metabolism, Jose Antonio Rosales

Open Access Theses & Dissertations

The hypothesis that deracemization of racemic ibuprofen (IBU) occurs via the enolization of a Candida rugosa lipase (CRL)-ibuprofen ester (Scheme 1.6.2) was disproven by reacting racemic IBU under the conditions that were used to deracemize ibuprofen methyl ester (IME), namely pH 7.6. At pH 7.6, IME through IBU butyl esters were not formed in-situ and racemic IBU was not deracemized by reacting the corresponding primary alcohol with racemic IBU in the presence of CRL.

At pH 7.6, hexyl through dodecyl IBU esters were formed in-situ by reacting the corresponding primary alcohol with racemic IBU in the presence of CRL. The …

Polymerized Ionic Liquids By Condensation Polymerization: Stimuli Responsive Polyurethane Gels And Dispersions, Harshit Gupta

Master's Theses and Doctoral Dissertations

Ionic liquids have been used in free radical polymerizations to make polymerized ionic liquid (PIL) materials of various types. PIL gels based on imidazolium cations have been found to exhibit an anion-exchange induced stimuli responsiveness. This thesis explores incorporation of ionic liquids in polyurethane (PU) polymers to make PIL PU gels and dispersions through condensation polymerization. PIL gels are synthesized through a single-pot approach that show stimuli response to solvents. This approach allows one to make these gels rapidly and cheaply on-site. These gels can reversibly porate in different solvents and are found to be porous when analyzed by scanning …

Uv-Curable Organic-Inorganic Hybrid Polyurethane Coating, Shiyin Yu

Master's Theses and Doctoral Dissertations

This thesis explored a series of organic-inorganic hybrid polyurethane oligomers with varying molecular weights and functional groups (acrylate and/or silane) that were cured with a single ultraviolet (UV) trigger but two photo-initiators. Upon UV irradiation, the free-radical initiator initiated a free-radical reaction for acrylate cross-linking, and the photo-latent base initiated a sol-gel reaction for condensation of the silanes. This study explored the cure extent of both reactions by FTIR for acrylates and silanes and a weight-loss method for silanes as a function of functional group concentration and time. The general film properties were also studied. The results showed that the …

Xflow: An Algorithm For Extracting Ion Chromatograms, Mathew M. Gutierrez, Rob Smith

Graduate Student Theses, Dissertations, & Professional Papers

Abstract: Mass spectrometry is a fundamental tool for modern proteomics. The increasing availability of mass spectrometry data paired with the increasing sensitivity and fidelity of the instruments necessitates new and more potent analytical methods. To that end, we have created and present XFlow, a feature detection algorithm for extracting ion chromatograms from MS1 LC-MS data. XFlow is a parameter-free procedurally agnostic feature detection algorithm that utilizes the latent properties of ion chromatograms to resolve them from the surrounding noise present in MS1 data. XFlow is designed to function on either profile or centroided data across different resolutions and instruments. This …

Antitumor Properties Of Imidazolium Salts, Jenna Frantz

Williams Honors College, Honors Research Projects

This is the final write-up for an honors research project for the University of Akron Williams Honors College. Synthesis of novel imidazolium salts was conducted. Following synthesis of imidazolium salts, the stability of the compound was tested at 37°C over a 72-hour period to give preliminary information about drug stability in vivo. 2D NMR was also conducted to confirm the structure of TPP-1. The student wrote an experimental protocol for the use of C57BL/6 mice and performed the online CITI training by the IRB to prepare to work with animals in a study of the antitumor properties of imidazolium salts …

Solvent Effects And Charge Transfer States In Organic Photovoltaics, Kangmin Liu

Wayne State University Dissertations

Due to their various advantages, including lightweight, flexible, and cheap manufacturing, organic photovoltaic materials have gained enormous research interest. Over nearly two decades, the power conversion efficiency of organic solar devices has increased dramatically. However, it is still low compared to traditional inorganic semiconductors. In order to improve efficiency, a better understanding of the basic thermodynamic properties of the light-to-electricity power conversion process is needed. One nontrivial aspect of organic solar cells is the low dielectric constant, which leads to tightly-bound excitons upon vertical excitations. The separation of electron-hole pairs requires a larger driving force to overcome the Coulombic binding …

X-Ray Crystal Structure Of Au36(Sph-Pch3)24 Nanomolecules, Vigneshraja Ganeshraj

Electronic Theses and Dissertations

Au36(SR)24 is one of the most comNanomolecules (NM) in gold NM field and crystal structures of Au36(SR)24 with different thiolate protecting ligand such as tert-butylbenzene thiol, thiophenol and cyclopentane thiol have been reported. It has been predicted that aromatic thiol protected Au36(SR)24 NM have same core structures like the other reported Au36(SR)24 NMs. Due to the steric and electronic conjugation effects the staples on the gold core exhibit minor changes in the bond length without affecting the gold core. By varying the Gold:Thiol ratio the NM size can be controlled. Herein, we report the synthesis, isolation and characterization of two …

Development Of Cobalt And Iron Catalysts Bearing Rigid Polydentate Ligands For Proton Reduction And C-H Bond Oxidation, Lizhu Chen

Electronic Theses and Dissertations

The demand for energy consumption has increased exponentially since the Industrial Revolution. The major source of this energy has been and continues to be fossil fuels. The depletion of fossil fuels and environmental concerns associated with their combustion has motivated us to develop a renewable energy alternative to meet future energy demands. Hydrogen is a clean energy alternative to fossil fuels, which can be generated from solar-driven water splitting. However, more efficient and inexpensive catalysts for the hydrogen evolution reaction (HER) are needed. In this context, hydrogen production has been investigated with a stable and highly reactive cobalt-based catalyst. While …

A Computational Approach To Predicting And Understanding New Psychoactive Substances (Nps) For Developing A Database For State And Federal Crime Laboratories, Caroline Amelia Spencer

Electronic Theses and Dissertations

The object of this dissertation was to use a computational approach to predict and understand new psychoactive substances (NPS) to develop a database for state and federal crime. The primary scope of the dissertation was to better understand the interactions that take place between new psychoactive substances and their corresponding receptors. Through analysis of the interactions between the amino acids within the receptors and the NPS an understanding into the pharmacology and toxicology of these drugs can be gained. NPS such as synthetic cannabinoids fentanyl and its analogs and kratom have become more problematic for both state and federal crime …

Effects Of Halogen Bonding And Nir Tuning Of Dyes For Dye-Sensitized Solar Cells, Alexandra Baumann

Electronic Theses and Dissertations

With current energy demands being met through the utilization of energy sources such as petroleum, natural gas, and coal, the non-renewable nature of these sources will eventually approach depletion as world wide energy consumption increases yearly. As a result the need for a renewable energy alternative has become imminent. One appealing alternative that has gained considerable attention since its development due to a low cost and a high solar to electric conversion efficiency are dye-sensitized solar cells (DSCs). This dissertation describes efforts to design and synthesize improved organic dyes utilizing three analogous methods: first, through decreasing non-productive pathways such as …

The Dynamic Nature And Biophysical Characterization Of Isu1, Fe-S Cluster Assembly Scaffold Protein In Saccharomyces Cerevisiae, And Its Significance To Human Disease, Brianne Elizabeth Lewis

Wayne State University Dissertations

Mitochondrial Fe-S cluster biosynthesis is accomplished within yeast utilizing the biophysical characteristics of the “Isu1” scaffold protein. As a member of a highly homologous protein family, Isu1 has sequence conservation with orthologs and a conserved ability to assemble [2Fe-2S] clusters. Regardless of species, scaffold orthologs can exist in both “disordered” and “structured” conformations and is directly related to conformations utilized during Fe-cofactor assembly. During assembly, the scaffold directs the delivery and the utilization of both Fe(II) and sulfide substrates in order to produce [2Fe-2S] clusters, however Zn(II) binding can alter the activity of the scaffold with stabilizing the protein in …

Metabolomic Analysis Of Urine From A Rat Model Relevant To Diabetes Using Nmr, Anna Hart

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

No abstract provided.

Antibacterial Efficacy Of Nanocarriers Designed To Target Pseudomonas Aeruginosa, Anna Mcalpin

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

No abstract provided.

Bayesian Automated Metabolite Analyzer For Nmr Spectra: Batman, Joseph Stuber

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

No abstract provided.