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Articles 151 - 171 of 171
Full-Text Articles in Chemistry
Development Of An On-Line Computer System For Cyclic Voltammetry Studies, Tai-Lee Leo Huo
Development Of An On-Line Computer System For Cyclic Voltammetry Studies, Tai-Lee Leo Huo
Chemistry & Biochemistry Theses & Dissertations
An Apple II Plus microcomputer was interfaced to a PAR 174A Polarographic Analyser, an HP 7O4OA X-Y recorder and a three-electrode system. This on-line computer system was applied to Cyclic Voltammetry (CV) studies. The interfacing involved both hardware and software development. Various hardware components were used to amplify and transmit the analog signal both going into the computer and coming from the computer. Software programs were written for staircase waveform generation, data acquisition, and plotting the voltammograms obtained.
A package was designed for CV experiments to be used by the students in the instrumental analysis laboratory. This package contains several …
The Synthesis And Evaluation Of A New Analog Of Phencyclidine (Pcp), William H. Johnson Jr.
The Synthesis And Evaluation Of A New Analog Of Phencyclidine (Pcp), William H. Johnson Jr.
Chemistry & Biochemistry Theses & Dissertations
Based on an interpretation of the literature of phencyclidine (PCP) together with an examination of the relevant models or prototype structures, this research has attempted to design and synthesize a rigid analog of the phencyclidine structure. The parent ring systems suggested for this study were the 1-arnino and 2-arninornethyltetralins, 10 and, 12.
Several organic compounds, based on this design, have been prepared by classical examples of reductive alkylation reactions of the corresponding 2-hydroxyciethylene-1-tetralones, 11, and by the condensation and subsequent reductive alkylation of the 1-arninotetralin, 9. These arninomethyltetralones, 28, 29 and 30, together with an example of a substituted 1-arninotetralin, …
Determination Of The Internal Rotational Energy Of Gaseous 1,2-Dichloroethane In An Argon Matrix Using Fourier Transform Spectroscopy, Susan Lynn Clarke
Determination Of The Internal Rotational Energy Of Gaseous 1,2-Dichloroethane In An Argon Matrix Using Fourier Transform Spectroscopy, Susan Lynn Clarke
Chemistry & Biochemistry Theses & Dissertations
A sample cell and delivery system for rapid matrix isolation of gas mixtures at constant gas temperature was designed and evaluated. The rotational energy differences of 1,2-dichlorosthane and of its deuterium compound wars then determined to test this technique.
The rotational energy barriers calculated from Boltzman plots of ths gases at different temperatures were; 1.21 + 0.38 keel/mole, 1.33 + 0.70 Real/mole, and 1.12 + 0.45 kcal/mole for the CH2 wagging„ C-Cl stretching and CD2 wagging modes respectively. These values were in good agreement with previously published values.
These results allowed evaluation of this apparatus and experimental design and …
Characterization Of Trihalomethane Formation From Proteins In Chlorinated Water, Robert Aaron Kravitz
Characterization Of Trihalomethane Formation From Proteins In Chlorinated Water, Robert Aaron Kravitz
Chemistry & Biochemistry Theses & Dissertations
Traditionally humates have been considered the most significant precursor in the formation of trihalomethanes in finished drinking water. This study investigates another potential precursor, namely proteins. The chlorination of aqueous protein solutions yields significant levels of trihalomethanes in terms of the maximum contaminant level (MCL) of 0.100 mg/L imposed by the USEPA. Molar yields for several proteins were determined. The average yield per unit of organic carbon was 0.5% as compared to 0.8% for a humic acid studied. A model protein, bovine serum albumin, was studied extensively to ascertain the effects of total organic carbon, chlorine dose, and time on …
Investigation Of Matrix Effects On The Furnace Atomic Absorption Signals Of Chromium, Nickel And Selenium, Susan Marie Viet
Investigation Of Matrix Effects On The Furnace Atomic Absorption Signals Of Chromium, Nickel And Selenium, Susan Marie Viet
Chemistry & Biochemistry Theses & Dissertations
The flameless atomic absorption signals of chromium, nickel and selenium are subject to matrix interferences arising from inorganic salts and anions commonly found in urine. The effects of such salts on the atomic absorption signals were investigated using Polarized Zeeman Effect background correction in conjunction with a detector/readout system capable of resolving absorbance signals in 18 msec readings. Both optical temperature control and current temperature control were employed for each analysis. Peak area, peak height, peak shape and appearance time were compared for matrix-free standards and matrix-containing standards.
The influence of the inorganic salts on the metal analyses was found …
Determination Of N,N'-Diphenylguanidine In Biological Tissues And Fluids Using High Pressure Liquid Chromatography, Edward Sidney Hunter Iii
Determination Of N,N'-Diphenylguanidine In Biological Tissues And Fluids Using High Pressure Liquid Chromatography, Edward Sidney Hunter Iii
Chemistry & Biochemistry Theses & Dissertations
N,N'-Diphenylguanidine (DPG) is a potentially toxic compound used in the vulcanization of rubber products. Distribution of DPG in hybrid mice (C57BL/6J interbred with DAB2) was determined following intraperitoneal injection. Urine, fecal material, whole blood and tissues were collected at various times after administration of DPG and the extracts analyzed for DPG by high pressure liquid chromatography. Recovery of DPG from spiked urine and whole blood exceed 90%, however, the recovery of DPG from spiked tissue samples was approximately 70%.
DPG concentration in whole blood reached a maximum within ten minutes and rapidly decreased through 180 minutes after administration …
Analysis Of Organic N-Chloramines In Chlorinated Drinking Water, John Po Wen Yang
Analysis Of Organic N-Chloramines In Chlorinated Drinking Water, John Po Wen Yang
Chemistry & Biochemistry Theses & Dissertations
This thesis describes the development of a sensitive method for the separation and quantitation of organic N-chloramines in chlorinated tap water. 5-Dimethylaminonaphthalene- l-sulfinic acid has been synthesized and characterized. It yields highly fluorescent dansyl derivatives on reaction with N-chloramines. Conditions of the derivatization were optimized for the detection of N-chloropiperidine at concentrations in aqueous solution of 10-7 M. The technique gives a quantity of derivative which is proportional to the concentration of chloramine present over the range examined (10-7 M to 10-4 M). High pressure liquid chromatographic separation of dansyl derivatives of amines and amino acids has …
The Temporal And Spatial Distribution Of Hydrocarbons In Atmospheric Deposition From Stations Surrounding Lower Chesapeake Bay, David Benjamin Webber
The Temporal And Spatial Distribution Of Hydrocarbons In Atmospheric Deposition From Stations Surrounding Lower Chesapeake Bay, David Benjamin Webber
OES Theses and Dissertations
Hydrocarbon concentrations were determined in bulk, wet, and dry deposition samples from urban and non-urban locations surrounding lower Chesapeake Bay. Mean hydrocarbon concentrations in bulk deposition samples were over three times greater at the urban station indicating a localized source. The major hydrocarbons present were n-alkanes, polycyclic aromatic hydrocarbons (PAH), and the unresolved complex mixture (UCM). The PAH and the UCM were an indication of significant anthropogenic inputs while the odd/even distribution of the n-alkanes was an indication of biogenic sources. These findings indicated seasonal trends of highest biogenic hydrocarbon inputs in the spring and summer months and highest anthropogenic …
Ortho Cyclization Reactions Of Catecholamines, Robert Lee Hudkins
Ortho Cyclization Reactions Of Catecholamines, Robert Lee Hudkins
Chemistry & Biochemistry Theses & Dissertations
A study was undertaken to examine the potential for ortho cyclization associated with the synthesis of 1,2,3,4,-tetrahydroisoquinolines using the Pictet-Spengler reaction. Specif1cally, the condensation of the biogenic amines, dopamine, norepinephrine and epinephrine were carefully examined in light of current literature and the facility and extent of ortho cyclization in each case. The para isomers of these three biogenic amine condensation products were isolated and characterized, while only the ortho isomer derived from dopamine was found stable and could be isolated, and structurally identified. These studies demonstrate that a second cyclization product does, in fact, form in each instance and that …
The Regioselective 3-Alkylation Of Piperidine, Richard Dunn Todd
The Regioselective 3-Alkylation Of Piperidine, Richard Dunn Todd
Chemistry & Biochemistry Theses & Dissertations
The compounds: 3-allylpiperidine, 3-ethylpiperidine and 3-n-butylpiperidine have been synthesized by regioselectively alkylating the three position of piperidine. Piperidine was converted to N-chloropiperidine and then dehydrohalogenated to produce Δ1-piperideine. The enamide anion was generated by adding solutions of Δ1-piperideine to ethylmagnesium bromide or lithium diisopropylamide. Addition of alkylhalides produced 3-alkyl- Δ1-piperideine which could be reduced or alkyllithiated to give 3-alkylpiperidines or 2,3-dialkylpiperidines respectively.
The yields of products were low and the reaction generated a continuum of mono- and di-alkylpiperidines and there was evidence that several dimeric piperideines were formed. The low yields were discussed in …
Synthesis Of Dihydroisoquinolines And Tetrahydroisoquinolines, John J. Schlager
Synthesis Of Dihydroisoquinolines And Tetrahydroisoquinolines, John J. Schlager
Chemistry & Biochemistry Theses & Dissertations
Dihydroisoquinolines and tetrahydroisoquinolines are compounds which possess a variety of pharmacological activities. New easier methods of synthetic manipulations of these structures is of constant interest in the pharmaceutical industry.
This paper describes a new three step method of preparing 1-alkyl- and 1-aryl-tetrahydroisoquinolines from a tetrahydroisoquinoline. The synthesis involves the N-chlorination of tetrahydroisoquinoline followed by dehydrohalogenation with potassium superoxide. The reaction products are the dihydroisoquinolines. Overall yields range from 85-96%. The unsubstituted, 1-methyl-, and 1-phenyl-J,4-dihydroisoquinolines have been formed. Organometallation of the unsubstituted dihydroisoquinoline provides the 1-substituted tetrahydroisoquinoline. The 1-benzyl-, 1-n-butyl-, 1-ethyl-, 1-methyl-, and 1-phenyl-1,2,J,4-tetrahydroisoquinolines were prepared. The use of Grignard and …
High Performance Liquid Chromatographic Analysis Of Biogenic Amines, Thais Edwina Ahrendt Keegan
High Performance Liquid Chromatographic Analysis Of Biogenic Amines, Thais Edwina Ahrendt Keegan
Chemistry & Biochemistry Theses & Dissertations
The objectives of this research were to develop a sensitive method for separation and quantitation of biogenic amines and to apply that procedure by monitoring neurochemical changes resulting from stimuli to the test system.
Primary aromatic amines were derivatized with o-phthalaldehyde-mercaptoethanol prior to chromatography, Separation of the fluorescent adduct was achieved using a μBondapak/ phenyl reversed-phase column and a two-step gradient of methanol:0.08 M acetic acid, pH J.O. Fluorescence was monitored using a J40 nm excitation energy and an emission filter which transmits radiation greater than 400 nm (50% T at 418 nanometers).
Following optimization of the chromatographic conditions, studies …
A Technique For The Isolation And Identification Of Aliphatic Amines In Water, Peter Alan Drew
A Technique For The Isolation And Identification Of Aliphatic Amines In Water, Peter Alan Drew
Chemistry & Biochemistry Theses & Dissertations
Small, aliphatic amines added to a basic, aqueous solution (16.2 L) at a concentration of 100 parts per billion were isolated by sorption on a small column of macroreticular resin. The amines were eluted with diethyl ether; the eluate concentrated, and the compounds separated and identified by gas chromatography. The efficiency of the recovery of a-nines ranged from 5 to 28%.
A protocol for derivatizing pyrrolidine and n-pentylamine in ether with fluorinated acylating agents was developed. The method was found to be adequate for the detection of approximately 13 micrograms of &-nines in concentrated ether extract.
Environmental water samples …
Chemistry Of Organic N-Chloramines, Formation Of Arenesulfonamides By Derivatization Of Organic N-Chloramine With Sodium Arenesulfinate, Katherine F. Bowdring
Chemistry Of Organic N-Chloramines, Formation Of Arenesulfonamides By Derivatization Of Organic N-Chloramine With Sodium Arenesulfinate, Katherine F. Bowdring
Chemistry & Biochemistry Theses & Dissertations
Organic N-chloramines are recognized by-products of chlorinated water systems. Because of their chemistry, none have been isolated or identified.
This paper discusses a method for the derivatization of the organic N-chloramines based on a nucleophillic substitution mechanism. N-Chloro derivatives of amines of various structures were studied including primary and secondary aliphatic amines, as well as amino acids. The effect of the presence of other functional groups including aromatic and unsaturated systems was investigated.
Derivatization was done by three different methods, one involving derivatization of the pure N-chloramine, and two involving derivatizations of the N-chloramine generated in situ. Seventeen arenesulfonamides have …
The Association Of 5.8 S With 28s Ribosomal Rna, Nandita Banerjee
The Association Of 5.8 S With 28s Ribosomal Rna, Nandita Banerjee
Chemistry & Biochemistry Theses & Dissertations
5.8S rRNA is a low molecular weight ribosomal RNA which is noncovalently bonded to the larger ribosomal subunit 28S rRNA; through its 3' end and through its 5' end. This interaction is an integral part of the ribosome, and plays an important role in the ribosome structure and function.
There is a high degree of homology between the 5.8S rRNA primary structures of rat, turtle and chicken. The base sequence of rat 5.8S rRNA differs only in one position from that of turtle and in three positions fr.om that of cl1.icken. Tl1ere is a single purine substitution at the 5' …
A Study Of The Gas-Solid Reaction Between Hydrogen Sulfide And Mercury(I) Chloride; Development Of A Method For Determination Of Atmospheric Hydrogen Sulfide, Eric H. De Carlo
A Study Of The Gas-Solid Reaction Between Hydrogen Sulfide And Mercury(I) Chloride; Development Of A Method For Determination Of Atmospheric Hydrogen Sulfide, Eric H. De Carlo
Chemistry & Biochemistry Theses & Dissertations
The possibility of measuring hydrogen sulfide indirectly by measuring the mercury evolved from the gas-solid reaction between hydrogen sulfide and mercury(I) chloride was studied. DMCS treated glass wool was coated with mercurous chloride and used as a conversion material. The response to hydrogen sulfide was studied as a function of concentration and temperature. The possible interference of other sulfur gases and water was examined.
The studies indicated that hydrogen sulfide could be determined at concentrations as low as 15 ppb. It was found that mercaptans would actively interfere with the hydrogen sulfide to mercury conversion, but that sulfur dioxide would …
The Synthesis Of New Maleimide Addition Polymer Precursors, Richard B. Brown
The Synthesis Of New Maleimide Addition Polymer Precursors, Richard B. Brown
Chemistry & Biochemistry Theses & Dissertations
1H-2,3-dimethylpyrrolo(1,2-a) benzimidazol-l-one (27) and 1H,9H- 2,3,7,8-tetramethyl-bispyrrolo(1,2-a:6,7-a')benzodiimidazo1-1,9-dione (32) have been synthesized from dimethylmaleic anhydride and o-phenylenediamine and 1,2,4,5-tetraaminobenzene, respectively. The presence of reactive olefinic double bonds in the synthesized compounds was of interest as a site for possible addition polymerization.
The synthetic route involved, in both cases, a simple nucleophilic substitution reaction between the diamine(or tetraamine) and the anhydride to form an intermediate amide-acid-amine which rapidly cyclized to the imide amine. The final ring closure required more rigorous conditions and occurred at melt reaction temperatures.
The Thermal And Photolytic Rearrangements Of Isatoic Acid Diazide, Ana Alejandre Ciereszko
The Thermal And Photolytic Rearrangements Of Isatoic Acid Diazide, Ana Alejandre Ciereszko
Chemistry & Biochemistry Theses & Dissertations
The primary objective of this research has been the thermolysis and photolysis of isatoic acid diazide 1. Thermolysis in low boiling solvents produced the acylazido benzimidazolone 10, while refluxing in high boiling solvents gave rise to the imidazoindazoline 31, presumably via Curtius rearrangements.
Photolysis of the diazide in methylene chloride gave rise to two photo products, 10 and 31, while photolysis in tetrahydrofuran produced only 31.
A study of the spectral and chemical characteristics of these products have been carried out.
The Synthesis And Characterization Of The 2,2'-Bisacylazide Of 2,2'-Diphenyldicarboxylic Acid, Subrata Chatterjee
The Synthesis And Characterization Of The 2,2'-Bisacylazide Of 2,2'-Diphenyldicarboxylic Acid, Subrata Chatterjee
Chemistry & Biochemistry Theses & Dissertations
The primary objective of this investigation w2s the photolytic and thermal characterization of a newly synthesized aromatic diacylazide, the 2,2'-bisacylazide~ of 2,2'-diphenyldicarboxylic acid 19. Photolysis of the azide in acetone ~ave rise to a mixture of photoproducts, one of which is a known system, 6(5-H)-phenanthridionone 28, while photolysis of 19 in ethanol gave ris,2 to the corresponding hydroxamic acid ester 40.
Complexes Of The 2,2'-Bisacylhydrazide Of 3,3'-Bipyridine And The Dipicolinic Acid Dihydrazide Ligand Systems, William Leo Johnson Iii
Complexes Of The 2,2'-Bisacylhydrazide Of 3,3'-Bipyridine And The Dipicolinic Acid Dihydrazide Ligand Systems, William Leo Johnson Iii
Chemistry & Biochemistry Theses & Dissertations
The copper(II) complexes of the picolinic acid bydrazide (PH), the dipicolinic acid dibydrazide (DPH), and the 2,2'-bisacylbydrazide of 3,3'-bipyridine (DAR) ligand systems have been prepared and have been characterized by infrared spectroscopy. Coordination has been proposed to occur between the terminal amine, the amide nitrogen, and the ring nitrogen in each of the respective complexes.
Evidence for the loss of the amide hydrogen upon complexation of PH, DPH, and DAH with copper(II) has been observed by the n.m.r. study of the zinc(II) complexes of the PH and DAH ligand systems. This is in support of the structures proposed above for …
The Synthesis And Characterization Of The 2,2'-Bisacylazide Of 3,3'-Bipyridine, Magdy Adly Guirguis El-Fayoumy
The Synthesis And Characterization Of The 2,2'-Bisacylazide Of 3,3'-Bipyridine, Magdy Adly Guirguis El-Fayoumy
Chemistry & Biochemistry Theses & Dissertations
The primary objective of this research has been the synthesis and characterization of a new heterocyclic diacylazide, the 2,2'-bisacylazide of 3,3'-bipyridine 19. This heterocyclic diacylazide has been successfully synthesized from the phenanthrolin-5,6-dione 14, and examined with regard to its.thermal and photolytic decomposition.
Thermal decomposition of this disacylazide seems to go by a double-barreled Curtius rearrangement leading to a series of pyridonaphthyridinone (20) compounds such as 22 and 29.
An initial study of the photolysis of this bisacylazide has been initiated to examine the possible formation of nitrene-type intermediates.