Chemistry Commons^™

Determination Of The N-Terminal Amino Acid Residues On Polypeptides In Secondary Wastewaters, Edward L. Creecy

Chemistry & Biochemistry Theses & Dissertations

The N-terminal amino acid residues on polypeptides and proteins were determined in wastewaters prior to chlorination. The terminal amino groups'ere first derivatized with the well known derivatizing agent dansyl chloride, and then the resulting dansyl amino acid hydrolyzed from the peptide chain by a propionic acid/ hydrochloric acid mixture. The resulting dansyl amino acids were then separated and detected using reversed phase high performance liquid chromatography with fluorescence detection. The majority of N-terminal residues detected were the more polar amino acids. Concentrations ranged from 1 x 10^-10 to 3 x 10^-7 moles/liter. It is suggested that the shorter …

Radicals, Metals And Magnetism, David J R Brook

Faculty Publications

The interaction between unpaired electrons governs many physical properties of materials. Although in a fundamental sense the interaction is simple, a full understanding of the interaction in molecular systems is complicated by the presence of other bonding and non-bonding electrons. The resulting many body problem is very challenging. Nevertheless, much qualitative understanding can be obtained from applying simple molecular orbital theory and considering only the partly filled orbitals. The resulting model can be used to describe existing diradical and metal-radical systems and also has predicative value in the search for molecular magnets and design of nanoscale devices.

Approaches To A Generalized Synthesis For Hexaphenylbutadiene, Karena Kaye Linkenhoger Robinson

Theses, Dissertations and Capstones

This study was concerned with the attempted development of a generalized synthesis of hexaphenylbutadiene. Three methods were attempted: Michael Addition of cyanide to -phenylcinnamate followed by organolithium or Grignard addition; reaction of benzil with two moles of the Wittig reagent prepared from bromodiphenylmethane; reaction of two moles of benzophenone with the bisphosphorane prepared from 1,2- dibromo-1,2-diphenylethane.

Radicals, Metals And Magnetism, David J R Brook

Faculty Publications, Chemistry

The interaction between unpaired electrons governs many physical properties of materials. Although in a fundamental sense the interaction is simple, a full understanding of the interaction in molecular systems is complicated by the presence of other bonding and non-bonding electrons. The resulting many body problem is very challenging. Nevertheless, much qualitative understanding can be obtained from applying simple molecular orbital theory and considering only the partly filled orbitals. The resulting model can be used to describe existing diradical and metal-radical systems and also has predicative value in the search for molecular magnets and design of nanoscale devices.

Environmental And Botanical Controls On Peatification - A Comparative Study Of Two New Zealand Restiad Bogs Using Py-Gc/Ms, Petrography And Fungal Analysis, Tomasz K. Kuder, Michael A. Kruge, J C. Shearer, S L. Miller

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study shows that chemical properties of two restiad species, Empodisma minus and Sporadanthus traversii, may contribute to their success as peat-formers in a climate of the North Island of New Zealand which is not conducive to raised mire development. Unlike Sphagnum, the equivalent northern hemisphere peat-former, restiads possess lignin in their tissues. In addition, the presence of non-lignin polyphenols (including tannins and phenolic acids) in restiads may be an important factor in peat formation due to the allelopathic decay retardation. Patterns of degradation of plant biopolymers have been examined and the pathway of degradation of monocotyledons (loss …

Petrographic And Chemical Properties Of Carboniferous Resinite From The Herrin No. 6 Coal Seam, John C. Crelling, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Resinite is a naturally occurring substance found in coal and derived from original plant resins. It is ubiquitous in North American coals and comprises 1 to 4% by volume of most Illinois coals. It has been commercially exploited in the western USA for use in adhesives, varnishes and thermal-setting inks. The major objectives of this study were: (1) to separate resinite macerals from the Herrin No. 6 coal seam and to carefully verify, by petrographic and fluorescence microspectrophotometric methods, that the separated material was indeed resinite; (2) to characterize the chemical composition of the separated resinite by Py–GC–MS techniques; and …

D/H Exchange In Nitro Diastereomers, Charles A. Kingsbury

Department of Chemistry: Faculty Publications

The two diastereomers of 4-nitro-1,3-diphenylpentan-1-one behave differently in deuterium for hydrogen exchange in DMSO-d6/D2O solutions using various bases as catalyst. Reaction of the erythro diastereomer gives largely the same diastereomer upon D/H exchange (retention), i.e., exchange exceeds epimerization. Pyridine and acetonitrile as solvents lead to faster epimerization than exchange. In the threo diastereomer (DMSO-d6 solution), epimerization exceeds exchange, and the anion to some extent regains the same hydrogen originally removed by the base on the opposite face. 2-Bromo-4-nitro-1,3-diphenylbutan-1-one undergoes ring closure to the cyclopropane faster than exchange (within seconds). The cyclopropane shows faster exchange than equilibration, i.e., retention of configuration, …

Analysis Of A Mixture Of Several Dihalonicotinic Acids By Gas Chromotography And Gas Chromotography-Mass Spectrometry, Cheryl L. Fossler, Frank L. Setliff, Ali U. Shaikh

Journal of the Arkansas Academy of Science

Six 2,5- and 5,6- dihalonicotinic acids in a mixture were converted to their corresponding methyl esters and then analyzed by gas chromatography and gas chromatography-mass spectrometry. Four methods of conversion were compared for their GC sensitivity, efficiency and analysis time. In Method #1, using HC1 and methanol as the reagents, the displacement of the halogens by chlorine (from HC1) at 2- and 6-positions was a common occurrence, rendering the method inefficient. In Method #2 (BF3/methanol), the displacement of halogens by methoxide was evident. Method #3 (dicyclohexylcarbodiimide/methanol) produced a mixture of derivatives with a poor yield. Method #4 (diazomethane) gave a …

Preparation Of Methyl 5-Chloro-6-Fluoronicotinate By Fluoride-Chloride Exchange, Frank L. Setliff, Leslie B. Coop

Journal of the Arkansas Academy of Science

No abstract provided.

An Approach To A Generalized Synthesis For 2-Halo-1,1-Diarylalkenes, Cheryll R. Roberts

Theses, Dissertations and Capstones

This study was concerned with the development of a generalized synthesis of halogenated 1,1-diarylalkenes. The alkylation of 1,1-diphenylethylene was carried out by the addition of organolithium compounds (C Li, PhLi, t-BuLi, n-BuLi). N-bromo-succinimide (NBS) was used for bromination. The reaction forming triphenylbromo-ethylene gave the largest percent yield (93.6%). The reaction forming 2-bromo-3,3- dimethyl-l,l-dipheny1-1-butene resulted in a 38.1% yield. Each product structure was confirmed by proton and carbon-13 nuclear magnetic resonance, and infrared spectroscopy.

Reductive Dechlorinatin Of A 2-Chloronicotinic Acid Under Finkelstein Conditions, Frank L. Setliff, Leslie B. Coop

Journal of the Arkansas Academy of Science

No abstract provided.

Glycals : An Extended Study Of The Ferrier-Dimerization, Andreas H. Franz

University of the Pacific Theses and Dissertations

C-linked disaccharides were synthesized from 3,4,6-tri-O-acetyl-D-glucal 1 (1,5- anhydro-3,4,6-tri-O-acetyl-1,2-dideoxy-D-arabino-hex-I-enopyranose), 3,4,6-tri-O- acetyl-D-galactal 2 (1,5-anhydro-3,4,6-tri-O-acetyl-1,2-dideoxy-D-lyxo-hex-1- enopyranose) and 3,4-di-O-acetyl-L-fucal 3 (1,5-anhydro-3,4-di-O-acetyl-1,2,6-tri-deoxy- L-lyxo-hex-1-enopyranose) under Lewis acid catalysis (Scheme 1) and compound 4 was further derivatized at the double bond. Dihydroxylation of the glucose dimer 4 gave high allo-diastereoselectivity. The reactions used in the derivatization of 1 were subsequently applied to 2 and 3. The overall yield of 3 was improved to 70 %. All three glycals (10% solution in toluene) reacted quickly with boron trifluoride to give dimerization products in 40-60% yield. Futile attempts at de-O-acetylation of the 2',3'-unsaturated dimer revealed the necessity of …

Nickel Catalyzed Cyclizations Of Alkynyl-Etones And Their Application To The Formal Synthesis Of Pentalenic Acid, Kevin Schlosser

Honors Theses

Pentalenic acid is a very important molecule because it is a biosynthetic intermediate of pentalenolactone, which has antibiotic effects on Grampositive/ negative bacteria and pathogenic fungi. These effects are due to its ability to inhibit glyceraldehyde 3-phosphate dehydrogenase.1 However, the total synthesis of pentalenic acid is very lengthy.2 This project will begin the process of finding a more convenient route to pentalenic acid. Previously in this laboratory there have been experiments conducted in the cyclization of enones with nickel (0)3 It is hypothesized that this method can be used to shorten the preparation of pentalenic acid. As illustrated by the …

A Hplc Method To Assay Mycotoxins - Fumonisin, Ochratoxin And Zearalenone, Nalini Sadagopan

Masters Theses

A HPLC method to quantitate the mycotoxins Fumonisin B1 (FB1), Ochratoxin A(OA), and Zearalenone (ZON) was developed and validated. Mycotoxins are secondary metabolites of fungi like Fusarium, Asperigillus and Penicillium that contaminate crops. They have a wide array of chemical structures which facilitate their analytical detection.

The analytical method consists of reverse phase chromatography and fluorescence detection. Sample cleanup was performed using SAX and C18 cartridges prior to analysis on the HPLC.

The method developed for FB1 is unique in that it is more sensitive, accurate, and reproducible than the existing methods. Automation is one of the salient features that …

Concentrations, Complexation And Speciation Of Total Dissolved Zinc In The Chesapeake Bay, Charles William Henry Iii

Chemistry & Biochemistry Theses & Dissertations

This is the first research to examine the horizontal, vertical, and temporal variability of total dissolved zinc, organic complexation of zinc, and zinc speciation in the Chesapeake Bay. Filtered (0.45μm) surface and bottom water samples were taken along the salinity gradient of the Chesapeake Bay in October 1993, March 1995, July 1995, and October 1995. Analysis by Differential Pulse Anodic Stripping Voltammetry (DP ASV) indicated that total dissolved zinc concentrations in the Bay ranged from 2.9 ± 0.7nM to 38.8 ± 2nM. Total zinc was highest at the northern end of the Bay (low salinity), approximately 10 times lower at …

Electrodeposition Of Copper Indium Sulfide Films From Organic Solutions, Arif Raza, Robert Engelken, Brandon Kemp, Imran Khan, Wasim Aleem, Chris Barber

Journal of the Arkansas Academy of Science

We report on organic solutions ofCuCl 2 ,InClg, and elemental sulfur for electrodepositing CuIn x Sv films. CuInS 2 and CuInSe 2 are promising solar cellmaterials; our work on CuInSg prefaces planned work on plating CuInSe 2 from nonaqueous solvents. Two promising solvent systems are (1) mixed propylcne carbonate and water and (2) mixed ethylene glycol, propionic acid, and water (Engelken et al., 1988). Gray-brown films ofCuInx Sy (nominally GuInS2 ) have been plated from both baths. Major problems include (1) reduction ofCu+2 to Cu and Cu x S by the solvent at high temperatures (T>l()0°C), hence depleting Cu+2,(2) …

Synthesis Of Nitrosyl Metallpoprphyrins, Thomas M. Braxton Jr.

McCabe Thesis Collection

Nitric oxide, NO, is a molecule with great versatility and importance. Made up of only a single atom of nitrogen and a single atom of oxygen, nitric oxide is perhaps one of the smallest paramagnetic molecules found in nature. The functions of NO in the body are not all known, but this molecule definitely plays a variety of roles. It is involved in the regulation of blood pressure, and it sometimes acts as a messenger for cells as well as a killer of them. It also is important in the defense of the body against foreign invaders. The significance of …

A Spectroscopic Study Of A Rationally Designed Zinc Binding Protein, Jill Funk

Honors Theses, 1963-2015

Recently, biomedical science has turned its drug research endeavors towards a philosophy known as rational drug design. Its goal is to avoid the guesswork and instead design and create the exact proteins that are needed. In order for rational drug design to be feasible, a better understanding of protein structure and function needs to be obtained. This research analyses the structure and function of a "rationally" designed mutation of the calcium binding protein parvalbumin. Parvalbumin was chosen because certain aspects of its composition facilitate analysis and in addition, there is extensive data already known about the protein. The mutation involved …

Scf-Mo Conformational Analysis Of Polycroconaine, T. E. Ezell, Jerry A. Darsey

Journal of the Arkansas Academy of Science

Abinitio calculations at the STO-3G basis set level using GAUSSIAN 92 were conducted on the monomer unit of polycroconaine, a conducting polymer with conductive properties similar to several metals, in order to determine the most probable conformation of the monomer. We also compared the energy difference between the highest occupied and lowest unoccupied molecular orbitals. Successive calculations were performed at dihedral angle intervals of 30° around the central bond of the monomer. Minimum energy was observed at 0° bond rotation, consistent with a theory that the polymer owes many of its conductive properties to a planar configuration in combination with …

Hammett Correlations Of Carbonyl 13c Chemical Shifts In A Series Of N-(4-Substituted Phenyl)-6-Chloro-5-Fluoronicotinamides, Frank L. Setliff, John W. Hawley, Alan D. Toland

Journal of the Arkansas Academy of Science

A series of nine N-(4-substituted phenyl)-6-chloro-5- fluoronicotinamides exhibited excellent correlations of their carbonyl 13C shifts (5CO,ppm as measured in DMSO) with the standard Hammett substituent constants (c?R) of the substituent inthe 4-position. The linear relationship was defined by the equation 8CO ¦ 1.22

Understanding Fertilisers For Table Grapes, B. H. Goldspink, I. Cameron, J. Campbell-Clause, N. Lantzke, C. Gordon

Viticulture research reports

A course run by the Department of Agriculture, Western Australia, August 1995.

The purpose of this publication is to clarify the role fertilisers play in commercial table grape production and to detail methods of selecting fertilisers. This selection process however is not easy as there are over 600 registered fertilisers in Western Australia.

In deciding which is the best fertiliser for a particular property many factors have to be considered. These include:

* Age of vine

* Rootstock

* Variety of table grape

* Soil type

* Soil chemistry

* Irrigation methods

* Previous fertiliser history Previous yield, vigour and …

A Study Of Euplotes Crassus Telomere Proteins And Related Genes, John Scott Perez

Department of Chemistry: Dissertations, Theses, and Student Research

A novel PCR technique used to amplify Euplotes crassus macronuclear chromosomes was developed to provide scientific proof that an Euplotes crassus 1.0 kb gene is not genetically related to an Oxytricha nova 1.8 kb β-telomere protein gene. Theories and experimental procedures associated with the development of this PCR technique were the product of research that will have a profound impact on future studies of telomere protein genes and telomeric DNA in a multitude of eukaryotic cells. The hypothesis that a β-telomere protein does not exist in Euplotes crassus was supported by the result of this study.

Expression of the recombinant …

Axial Asymmetry In The Nuclear Magnetic Resonance Spectra Of Deuterated Methyl Groups: An Alternative Explanation, Mieng-Hua Wann, Gerard S. Harbison

Gerard S. Harbison Publications

The deuterium nuclear magnetic resonance (NMR) powder spectra of methyl groups at ambient temperatures are invariably averaged by rotation or hopping about the C₃ axis. The canonical result for a perfectly threefold symmetric methyl is an axially symmetric Pake doublet whose splitting, in the case of perfect tetrahedral angles around the group, is averaged by a factor of exactly three. However, deuterium NMR spectra of methyl groups are often somewhat axially asymmetric, indicating a significant deviation either of the methyl group, or of its environment, from threefold symmetry. Previous explanations for this phenomenon have hinged on either an additional …

Bulletin 4283 - Nitrogen Fertilisers For Cereal Production, M. G. Mason

Bulletins 4000 -

Because fertiliser prices are high, it is important to understand what affects the response to fertilisers by crops.

Among the many factors influencing crop response to nitrogen applications, the most important are the season, soil type, paddock history, time of application and source of nitrogen. Before deciding whether to use nitrogen on a cereal crop, which source to use and at what rate, you need some understanding of how these factors work.

Greatest responses to nitrogen fertilisers can be expected in areas with a relatively long growing season. In such areas light soils with a low nitrogen status give the …

Synthesis Of Malathion, Malaoxon, And Isomalathion Enantiomers And Examination Of Their Interactions With Acetylcholinesterase, Clifford E. Berkman

Dissertations

No abstract provided.

Effective, Reliable, Inexpensive Cryofixation Device, Lawrence A. Mink, Roger A. Buchanan

Journal of the Arkansas Academy of Science

No abstract provided.

Analysis Of Ammunition By X-Ray Fluorescence, Michael W. Rapp, Teddy L. Townsend

Journal of the Arkansas Academy of Science

Nondestructive analysis of lead shotgun pellets by X-ray fluorescence (XRF) shows considerable promise in assignment of the identity of the ammunition source. X-ray fluorescence spectra of various shotgun pellets and of standard alloys were obtained using an energy-dispersive instrument and an Am-241 source. The correlation obtained between the precent antimony in the standard alloys and the intensity of the Ka fluorescence peak from antimony was excellent. Peak areas from antimony in shotgun pellets were measured and compared to calibration plots from the standard alloys. The method was capable of distinguishing among lead-based alloys, such as ammunition, with antimony content as …

Reaction Of Titanocene Dichloride With Acetylenedicarboxylate, Tanya L. Hagler, Mark Draganjac, Paul M. Nave, J. Ed Bennett, Farooq Kahn, Robert Engelken, Gerard Williams, Chris Poole, Kwok Fai Yu

Journal of the Arkansas Academy of Science

The reaction of Cp2TiCl2 with either the mono- or dipotassium salt of acetylenedicarboxylic acid (ADC) gives high yields of an insoluble orange product. The insoluble compound shows potential semiconductor behavior, as evidenced by an apparent bandgap in the orange region of the visible spectrum. Under N2 ,the compound decomposes at 238° C, eventually losing approximately 46% total mass up to 1350° C. The exothermic decomposition in air, beginning at 235° C, results in the formation of titanium oxides.

Boron Phosphate And Aluminum Phosphate Aerogels, David A. Lindquist, Steven M. Poindexter, Sterling S. Rooke, D. Ritchie Stockdale, Kirk B. Babb, Alison L. Smoot, William E. Young

Journal of the Arkansas Academy of Science

Anhydrous sol-gel condensation of triethyl phosphate [(CH3CH2O)3PO] with boron trichloride (BCL3 ) or triethyl aluminum [(CH3CH2 ) 3A1] in organic solvents, led to formation of metallophosphate gels. The pore fluid of the gels was removed under supercritical conditions in a pressurized vessel to form aerogels. The aerogels were then calcined at progressively higher temperatures to produce high surface area phosphates. Since the initial gel reagent mixtures contained several NMR active nuclei, the condensation chemistry prior to the gel point was monitored by solution nB NMR. The surface areas, distribution of pore sizes, and total pore volumes of the aerogel products …

Hammett Correlations Of Half-Wave Reduction Potentials In A Series Of N-(Aryl Substituted)-Dichloronicotinamides, Cecil C. Persons, Ali U. Shaikh, Julie Shiflett, Frank L. Setliff

Journal of the Arkansas Academy of Science

Excellent correlations of Hammett substituent constants (sigmaR) of a series of N-(R-substituted aryl) -2,6-, 2,5-, and 5,6- dichloronicotinamides with polarographic half-wave potentials were observed. Although the correlations demonstrate that all three series of amides experience comparable sensitivity to the R groups at the carbonyl reduction site, the relative ease of reduction varies according to the chlorine substitution pattern on the pyridine ring. These differences are suggested to be due to combinations of mesomeric, inductive, and field effects which operate differently in the three systems. Correlation analysis also revealed that Hammett heteroatomic replacement constants previously determined by NMR studies are valid …