Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Chemistry

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 31501 - 31530 of 33287

Full-Text Articles in Entire DC Network

Ditertiary Phosphines As Monodentate Ligands In Transition Metal Carbonyl Complexes, Yih-Yau York Sun Jan 1978

Ditertiary Phosphines As Monodentate Ligands In Transition Metal Carbonyl Complexes, Yih-Yau York Sun

Masters Theses

Carbonyl complexes of chromium, molybdenum and tungsten have been synthesized in which two potentially chelating tetraphenyldiphosphinoethane molecules (Ph2PCH2CH2PPh2) are bound as monodentate ligands. The reaction of trans-(CO)4M(PPh2CH=CH2)2 (M = Cr, Mo, W) with diphenylphosphine (PPh2H) in the presence of potassium t-butoxide yields trans-(CO)4M(PPh2CH2CH2PPh2)2. The complexes, which represent the first of this type to be synthesized, have been characterized by 31P nmr. From the XAA'X' phosphorus-31 spectra of the …


Direct Determination Of Pentachlorophenol By Differential Pulse Polarography, Albert L. Wade Jan 1978

Direct Determination Of Pentachlorophenol By Differential Pulse Polarography, Albert L. Wade

Theses and Dissertations

Concern over environmental contamination leading to the introduction of pentachlorophenol into human and animal systems has resulted in the need for a rapid and direct method for determining trace concentrations of this highly toxic compound. A direct electrochemical procedure has been developed for determining trace conccentrations of this phenol dovm to 0.27 ppm. This method uses the electrochemical techniques of differential pulse polarography at the dropping mercury electrode, and differential pulse voltammetry at the carbon paste electrode to reduce pentachlorophenol for this determination. Cyclic voltammetry at the hanging mercury drop electrode has been used to characterize the reaction behavior of …


Developmental Dyslexia: Evidence For A Subgroup With A Reversal Of Cerebral Asymmetry, Daniel B. Hier, Marjorie Lemay, Peter B. Rosenberger, Vincent P. Perlo Jan 1978

Developmental Dyslexia: Evidence For A Subgroup With A Reversal Of Cerebral Asymmetry, Daniel B. Hier, Marjorie Lemay, Peter B. Rosenberger, Vincent P. Perlo

Chemistry Faculty Research & Creative Works

The Computerized Brain Tomograms of 24 Patients with Developmental Dyslexia Were Analyzed for Cerebral Asymmetry. Ten Patients Showed a Reversal of the Pattern of Asymmetry Regularly Observed in Normal Right-Handed Individuals So that the Right Parietooccipital Region Was Wider Than the Left. the Ten Dyslexic Patients with This Reversal of Cerebral Asymmetry Had a Lower Mean Verbal IQ Than the Other 14 Dyslexic Patients in This Study. the Reversal of Cerebral Asymmetry that Occurred in Ten of the Dyslexic Patients May Result in Language Lateralization to a Cerebral Hemisphere that is Structurally Less Suited to Support Language Function and Thus …


The Synthesis And Characterization Of Several Copper (Ii) Complexes Of Quinuclidinone-Containing Ligands. Possible Models For Type I Copper Blue Proteins., Victor Thomas Wilcox Jan 1978

The Synthesis And Characterization Of Several Copper (Ii) Complexes Of Quinuclidinone-Containing Ligands. Possible Models For Type I Copper Blue Proteins., Victor Thomas Wilcox

Masters Theses

Several copper (II) complexes with bidentate quinuclidinone containing ligands have been synthesized and characterized. These complexes appear to be possible models for the type I copper (II) in the copper "blue" proteins. The spectral and magnetic properties indicate that the complexes have a pseudo tetrahedral microsymrnetry about the central metal ion. The complexes contain chromophores of the following forms: CuN4, CuN2O2, and CuN2x2, where X is either Cl or Br. While the spectra of these complexes lack the intense 17,000 cm-1 band typical of copper "blue" proteins, the optical …


Emulsification And The Hlb-Temperature, Stig Friberg, Concepcion Solans Jan 1978

Emulsification And The Hlb-Temperature, Stig Friberg, Concepcion Solans

Chemistry Faculty Research & Creative Works

No abstract provided.


The Product Distribution And Structural Assignment Of The Monobromination Products Of 7-Hydroxy-2,2,5-Trimethylchroman-4-One, Marsha L. Dutkowski Jan 1978

The Product Distribution And Structural Assignment Of The Monobromination Products Of 7-Hydroxy-2,2,5-Trimethylchroman-4-One, Marsha L. Dutkowski

Dissertations and Theses @ UNI

The compound 6-bromo-7-hydroxy-2,2,5-trimethylchroman-4-one (1) was desired for use in a project directed toward the synthesis of two novel depsidones. Since 7-hydroxy-2,2,5-trimethylchroman-4-one (2) was readily available, a number of bromination conditions were investigated in an attempt to find a regiospecific synthesis of 1. However, mixtures of varying composition of 1, 2, 3 and 4 were obtained under all the conditions tried. Final separation of 1 and its isomer 3 was accomplished by a mixture of chromatographic techniques. Structural assignment of the two brominated products 1 and 3 was made by a combination of carbon and proton NMR.


Mechanism Of The Ninhydrin Reaction, Carey B. Bottom, Samir B. Hanna, Donald J. Siehr Jan 1978

Mechanism Of The Ninhydrin Reaction, Carey B. Bottom, Samir B. Hanna, Donald J. Siehr

Chemistry Faculty Research & Creative Works

No abstract provided.


Synthesis And Studies Of A Carbon-13 Labelled Chemical Carcinogen, Robert E. Royer Dec 1977

Synthesis And Studies Of A Carbon-13 Labelled Chemical Carcinogen, Robert E. Royer

Chemistry and Chemical Biology ETDs

Derivatives of 6-methylbenzo[a]pyrene enriched to 90% carbon-13 at the methyl carbon were synthesized. Reactions of the carcinogen, 6-chloromethylbenzo[a]pyrene, with nucleophiles under solvolytic conditions were studied kinetically and, using labelled 6-chloromethylbenzo[a]pyrene, the reaction products were studied by CMR. The purpose was to characterize the selectivity of the benzo[a]pyrenyl- 6-methyl carbonium ion in its reactions with some simple nucleophiles and with nucleosides and other nucleic acid components.

Although the solvolysis of 6-chloromethylbenzo[a]pyrene in aqueous/organic solution is first order, information about the course of the reaction can be obtained, under certain circumstances, from rate constants. Thus, if the rate of solvolysis is slowed …


Physical Studies Of Hg(Ii) And Ag(I) Dna Complexes, Dawen Ding Dec 1977

Physical Studies Of Hg(Ii) And Ag(I) Dna Complexes, Dawen Ding

Chemistry and Chemical Biology ETDs

The binding of Hg(II) and Ag(I) to the bases of DNA and polynucleotides induces strong absorption and CD bands. From electric dichroism studies, the transition moment of the difference absorption band at 293 nm is in the plane of the bases and has a huge negative CD band at 285 nm; while the corresponding 293 nm difference absorption band of DNA-Ag(I) complex is relatively CD inactive. A second band at 270 nm in the difference absorption spectrum of the DNA-Ag(I) complex has a large associated CD band at 270 nm. This transition is out of the plane of the bases. …


Photochemical Studies Of Hydroxo-Bridged Complexes Of Chromium (Iii), Ronald Raymond Ruminski Dec 1977

Photochemical Studies Of Hydroxo-Bridged Complexes Of Chromium (Iii), Ronald Raymond Ruminski

Chemistry and Chemical Biology ETDs

The acid solution and solid state photolysis in both visible and ultraviolet regions of the spectrum for µ-hydro­xo-bis[pentaamminechromium(III)] chloride, and the solution photolysis in the visible and 1 traviolet region of the spectrum for µ-hydroxo-bis[pentaarnrninechr rnium(III)] perchlorate, have been studied. The ultraviolet irradiation of µ-hydroxo-bis[pentaamminechromium(III)] chloride in HCl and CHlO4 produces a redox photoproduct identified as HCrO4-, although the rate of production of HCrO4- in HClO4 is slower than in HCl. Photochemical cleavage of the hydroxo-bridge occurs in the ultraviolet photolysis of µ -hydroxo-bis[pentaanuninechromium(III)] chloride and is 1.9 times faster than the corresponding …


Involvement Of Hemerythrin Sulfhydryl Groups In Heavy Atom Binding And Subunit Interactions, Suzanne Elizabeth Clarke Dec 1977

Involvement Of Hemerythrin Sulfhydryl Groups In Heavy Atom Binding And Subunit Interactions, Suzanne Elizabeth Clarke

Dissertations and Theses

Hemerythrin is a respiratory protein found in the erythrocytes of certain marine invertebrates. Structures have been obtained by x-ray crystallography for hemerythrins from Phascolopsis gouldii (P. gouldii) and Themiste dyscritum (T. dyscritum). Since many proteins are inactivated upon binding heavy metals such as mercury, an investigation of mercury-protein interactions in this protein was undertaken. In order to understand the nature of heavy-metal protein interactions in T. dyscritum it was necessary to identify the metalloprotein ligands since neither the liganding amino acid residues nor the geometry of the mercury complexes could be identified in the crystallographic studies.


Lattice Dynamics In Covalent Solids: Sn In Sns2_Xsex (0≤X≤2), Rolfe H. Herber, Ann E. Smelkinson, Michell J. Sienko, Lynn Schneemeyer Dec 1977

Lattice Dynamics In Covalent Solids: Sn In Sns2_Xsex (0≤X≤2), Rolfe H. Herber, Ann E. Smelkinson, Michell J. Sienko, Lynn Schneemeyer

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Mössbauer effect studies using the 23.8 keV gamma transition in 119Sn have been carried out on the system SnS2-xSe x (O≤x≤2) on both microcrystalline powders and single crystal samples. The composition dependence of the isomer shift parameter for the single line resonance spectrum shows that the covalency increases as x increases; the 5s electron population of tin in SnSe2 is ∼0.13 greater than it is in SnS2. From the temperature dependence of the area under the resonance curve it is possible to extract a Mössbauer lattice temperature θM which is only weakly dependent on composition for samples prepared in an …


Erratum: A Comparison Of The Rough Sphere Rotational Diffusion Model With Experimental Results For Liquid Methyl Iodide, Scott Whittenburg Dec 1977

Erratum: A Comparison Of The Rough Sphere Rotational Diffusion Model With Experimental Results For Liquid Methyl Iodide, Scott Whittenburg

Chemistry Faculty Publications

No abstract provided.


Observation Of Davydov Splitting In Pts Polydiacetylene Crystal Spectra, Hans Muller, Craig J. Eckhardt Dec 1977

Observation Of Davydov Splitting In Pts Polydiacetylene Crystal Spectra, Hans Muller, Craig J. Eckhardt

Craig J. Eckhardt Publications

The electronic spectra of polydiacetylene crystals have often been typified by poly-2, 4-hexadiyne-1, 6-diol-bis-(p-toluene sulfonate) (PTS). The spectra of crystals of this polydiacetylene have been unique in that they have displayed a pronounced “doubling” of the 300 K spectral bands at temperature below 170 K. The reflection bands are also observed to undergo a continuous red shift with continued decrease of temperature. The reflection band observed at lowest energy at 300 K is resolved at 77 K into two clearly separated bands at 15,700 cm-1 (Ib) and 16,050 cm-1(IIb). A recent study by modulated piezoreflection …


The Effects Of Various Pyrolysis Conditions On The Release Of Products From Green River Oil Shale, Georgia Thomas Fritz Nov 1977

The Effects Of Various Pyrolysis Conditions On The Release Of Products From Green River Oil Shale, Georgia Thomas Fritz

Chemistry and Chemical Biology ETDs

The fusion of oil shales with eutectic mixtures of inorganic salts was studied with the objective of finding a chemical means of releasing the organic material either at a lower temperature or with a lower empirical activation energy (Ea). Experimental techniques by which the pyrolysis of oil shale was studied were thermogravimetry (TG), evolved gas detection (EGD), and pyrolysis/thin-layer chromatography (TLC). The following fused salts were investigated (ratios in mo1%): LiCO3/Na2co3/K2CO3, 43.5/31.5/25.0; KSCN/NaSCN, 73.75/26.25; KSCN/­NaSCN, 70/30; Na2SO4/K2SO4/ZnSO4, 29.1/30.2/40.7; NaCl/Na2CO3 …


The Chemistry Of Sf₅Br And Sf₅Cf=Cf₂ - Addition Reactions, Robin J. Debuhr Nov 1977

The Chemistry Of Sf₅Br And Sf₅Cf=Cf₂ - Addition Reactions, Robin J. Debuhr

Dissertations and Theses

Addition reactions of pentafluorosulfur bromide (SF5Br) with fluoroolefins were studied. Three new adducts were prepared, SF5CHFCHC1Br, SF5CH2CH(CF3)Br, SF5CHFCFC1Br. SF5Br and CFC1=CHC1 yielded a small amount of product but attempts to add SF5Br to CF2=FCOF were unsuccessful.

The mechanism for these addition reactions seems to involve a free radical addition pathway. Steric factors seem to be important in determining whether SF5Br will add to fluoroolefins.

The new compounds, SF5CF(CF3)COF and SF5CF(CF3 )CONH2 have …


Determination Of The Rate Of Formation Of Hcn, Mitchell Hull Nov 1977

Determination Of The Rate Of Formation Of Hcn, Mitchell Hull

Honors Theses

Nitric oxide is a major air pollutant arising from fossil fuel combustion, yet the fuel contribution to its formulation is uncertain. Since, in combustion, fossil fuels undergo disintegration before oxidation takes place, the study of the pyrolsis of a model constituent of fossil fuels can shed light on NO formation. The rate of inert pyrolytic disappearance of pyridine and the rate of formation of the principal Nitrogen-containing pyrolytic product, HCN, was studied in an inert atmosphere. The rate constant for the formation of HCN and its temperature dependence were determined.


Thermochromism In A Polydiacetylene Crystal, R.R. Chance, R.H. Baughman, H. Muller, Craig J. Eckhardt Oct 1977

Thermochromism In A Polydiacetylene Crystal, R.R. Chance, R.H. Baughman, H. Muller, Craig J. Eckhardt

Craig J. Eckhardt Publications

Specular reflection spectra are reported for a thermochromic polydiacetylene crystal, ETCD [substituent group – (CH2)4OCONHC2H5] over the temperature range 23–130°C. A reversible thermochromic phase change occurs at ~120°C and is accompanied by a 2750 cm-1 blue shift in the reflection spectra. Evidence is presented which strongly suggests that the dramatic change in optical properties of ETCD at the phase transition is due to an acetylene to butatriene transformation in the bonding sequence of the polydiacetylene backbone.


4th Annual Umr-Dnr Conference On Energy -- Entire Proceedings, University Of Missouri--Rolla Oct 1977

4th Annual Umr-Dnr Conference On Energy -- Entire Proceedings, University Of Missouri--Rolla

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

No abstract provided.


Erratum: Light Scattering Studies Of Transverse Sound Wave And Molecular Motion In Benzonitrile, Scott Whittenburg Oct 1977

Erratum: Light Scattering Studies Of Transverse Sound Wave And Molecular Motion In Benzonitrile, Scott Whittenburg

Chemistry Faculty Publications

No abstract provided.


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 Oct 1977

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 …


19th Annual Conference On Analytical Chemistry Aug 1977

19th Annual Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 19th annual meeting of the Conference on Analytical Chemistry, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, August 1-3, 1977.


The Preparation And Study Of Some Bridged Tropones, Sultan T. Abu-Orabi Aug 1977

The Preparation And Study Of Some Bridged Tropones, Sultan T. Abu-Orabi

Masters Theses

No abstract provided.


High Pressure Liquid Chromatographic Methods For The Separations Of Derivatized Alpha-Keto Acids And Thiamine Phosphate Esters, Bruce Clark Hemming Aug 1977

High Pressure Liquid Chromatographic Methods For The Separations Of Derivatized Alpha-Keto Acids And Thiamine Phosphate Esters, Bruce Clark Hemming

Theses and Dissertations

Improved methods have been developed for separation of a-keto acid derivatives and for thiamine and its phosphate esters. Linear gradient reverse phase chromatography using ion-pair formation provides baseline resolution for a seven-component homologous series of a-keto acid dinitrophenylhydrazones having increasing carbon chain lengths. Branched-chain keto acids can also be separated. Aldehyde derivatives were examined as possible interfering compounds. Peak identification in biological material was confirmed for pyruvate by an enzymic peak shift technique. Monitoring near 365 nm permits low nanogram detection. Preliminary studies of keto acids in biological material illustrate the method's applicability. The same system with slight changes separates …


A Photochemical Study Of S-Triazolo[4,3-B] Pyridazine And 3-Diazo-4-Oxo-3,4-Dihydroquinoline, John Timothy Carlock Aug 1977

A Photochemical Study Of S-Triazolo[4,3-B] Pyridazine And 3-Diazo-4-Oxo-3,4-Dihydroquinoline, John Timothy Carlock

Theses and Dissertations

When subjected to ultraviolet radiation in the presence of an alkene, s-triazolo[4,3-b]pyridazine (STP) undergoes an unusual 3 + 2 photocycloaddition wherein the alkene adds to the 1 and 8 positions of STP with concommitant N4-N5 bond cleavage yielding 5,6-disubstituted-6,7-dihydro-7-methylene (and 7-cyanomethyl)-5H-pyrrolo[1,2-b]-s-triazoles. Amides and esters of indole-3-carboxylic acid have been synthesized by a novel reaction employing the ultraviolet irradiation of 3-diazo-4-oxo-3,4-dihydroquinoline (QDA) in the presence of amines or alcohols respectively. QDA, when irradiated, is postulated to undergo an internal Wolff Rearrangement to Indole-3-ketene which can add any amine or alcohol to form the corresponding amide or ester in modest to good …


Proximity Effects. Kinetics, Mechanisms And Reactivity Correlations For The Acidic And Alkaline Hydrolysis Of Ortho-Substituted-N-Methylbenzohydroxamic Acids, Irl E. Ward Aug 1977

Proximity Effects. Kinetics, Mechanisms And Reactivity Correlations For The Acidic And Alkaline Hydrolysis Of Ortho-Substituted-N-Methylbenzohydroxamic Acids, Irl E. Ward

Dissertations

No abstract provided.


The Synthesis Of Novel Macrocyclic Multidentate Compounds From Dioxodioic Acids (1), R. Elliott Asay Aug 1977

The Synthesis Of Novel Macrocyclic Multidentate Compounds From Dioxodioic Acids (1), R. Elliott Asay

Theses and Dissertations

A series of novel macrocyclic multidentate crown compounds have been prepared from a series of dioxodioic acids. The dioxodioic acids were prepared by treating various oligoethylene glycols or amines with maleic, succinic, citraconic, and glutaric anhydrides. The crown compounds were then synthesized from the dioxodioic acid chlorides obtained from the diacids and various oligoethylene glycols or ethylene diamine.


Real-Time Computer Optimized Scanning Potential Coulometry For Multi-Component Trace Analysis, Norman W. Petty Aug 1977

Real-Time Computer Optimized Scanning Potential Coulometry For Multi-Component Trace Analysis, Norman W. Petty

Theses and Dissertations

The instrumentation and methodology for real-time computer controlled scanning potential coulometry for multi-component trace analysis is described. The sensitivity limit was determined to be 10^-8 F for electrochemically reversible constituents. The sensitivity limit could be extended if measures were taken to compensate for the periodic signal found on the electrolysis current. Non-linear least squares curve fitting methods accurately resolved iron-platinum and silver-iron interferences to give accurate determinations for iron and silver. The resolving capability of this method was tested using theoretically generated scanning potential coulograms. The computer resolved sample constituents with a 1 to 100 concentration ratio and a formal …


High Spin-Low Spin Crossover And Antiferromagnetic Interactions In Tris(1-Pyrrolidinecarbodithioato)Iron(Iii) And The 4-Morpholine (Fem) And Dibutyl Analogs, Effect Of Recrystallization Solvent, And Crystal Structure Of Fem·Nitrobenzene, Edward J. Cukauskas, Bascom Sine Deaver, Ekkehard Sinn Aug 1977

High Spin-Low Spin Crossover And Antiferromagnetic Interactions In Tris(1-Pyrrolidinecarbodithioato)Iron(Iii) And The 4-Morpholine (Fem) And Dibutyl Analogs, Effect Of Recrystallization Solvent, And Crystal Structure Of Fem·Nitrobenzene, Edward J. Cukauskas, Bascom Sine Deaver, Ekkehard Sinn

Chemistry Faculty Research & Creative Works

High sensitivity magnetic susceptibility determinations, especially in the range 1.2-4.2 K on pure and dilute tris(pyrrolidinecarbodithioato)iron(III) (FeP) in its high spin form, show that a maximum at about 2 K is caused by antiferromagnetic interactions. The analogous chromium(III) complex does not exhibit significant antiferromagnetism compared to that of the iron complex, and it is likely that the upper e electrons possessed by the iron and not by the chromium are responsible for the bulk of the antiferromagnetism. As the iron atoms are about 9 Å apart in discrete molecules, the antiferromagnetic interactions presumably occur between unpaired spins delocalized on to …


Determination Of Mercury By Photoacoustic Spectroscopy, Robert Allen Cary Jul 1977

Determination Of Mercury By Photoacoustic Spectroscopy, Robert Allen Cary

Dissertations and Theses

A new detector for atomic spectroscopy was developed based on the photoacoustic principle. A simple system was constructed based on this detector and applied to the trace analysis of mercury. The detection limit was found to be about 0.2 μg/1 of mercury with a one milliliter sample.