Physical Sciences and Mathematics Commons^™

The Total Synthesis Of A Conformationally Constrained Organophosphorus Analog Of Acetycholine, Justin Mergott '98

Honors Projects

We propose the total synthesis of a conformationally constrained organophosphorus analog of acetylcholine (5, Scheme 5). This compound will contain two crural centers, one being the phosphorus atom and the other being the pyrrolidine ring carbon beta to the phosphorus atom. The chiral beta carbon is conformationally constrained because it is part of the pyrrolidine ring. Studies with such a compound should allow us to make substantial progress towards the clarification of the stereospecificity of AChE inhibition by OP compounds and eventually help us understand more about the structure of the AChE active site. The synthesis begins with Cbz-L-proline methyl …

Fuel Cells, Frederick J. Munster Jr.

Maine Collection

Fuel Cells

by Frederick J. Munster Jr.

Edited by: Mr. Christopher Carroll

Maine Department of Economic Development, Augusta, Maine, 1998.

Contents: Hydrogen / Hydrogen Safety / Electrolysis / Electrolyzers / History of Fuel Cells / How Fuel Cells Operate / Fuel Cell Types / Fuel Cell Electrochemistry / Power Systems / Fuel Cells in Transportation / Hydrogen Powered Internal Combustion Engines / Home, Garden, Education and Industry / For More Information / Glossary / References

On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Year 1, Peter J. Popp, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Final Technical Report For Its For Voluntary Emission Reduction: An Its Operational Test For Real-Time Vehicle Emissions Detection, Gary A. Bishop, Donald H. Stedman, R. Bruce Hutton

Fuel Efficiency Automobile Test Publications

No abstract provided.

Selective Selenoxide Elimination On The Secondary Face Of Beta-Cyclodextrin, Ahmed M. Hafez

Dissertations, Theses, and Masters Projects

No abstract provided.

The Jampatilla Obsidian Source: Identifying The Geological Source Of Pampas Type Obsidian Artifacts From Southern Peru, Richard L. Burger, Katharina J. Schreiber, Michael D. Glascock, Jose Ccencho

Andean Past

No abstract provided.

Archaeomagnetic Results From Peru: A.D. 700-1500, Daniel Wolfman, Richard E. Dodson

Andean Past

No abstract provided.

Characterization Of An All-Optical Device Based On Organic Materials, Hans-Martin Keller, Mark Andreas Bader, Gerd Marowsky

Turkish Journal of Chemistry

We present numerical and first experimental results for an all-optical switching device. The device consists of a periodically modulated nonlinear waveguide, where so-called gap solitons stabilize the switching process. The fabrication of Bragg gratings in different polymeric films, e.g. poly(phenylene vinylene), polydiacetylene or polystyrene by excimer laser photoablation was tested. In preparation of further experiments numerical calculations were performed to characterize the device under realistic conditions, including position dependent index modulations and absorption losses. In further time-dependent simulations the transition from the reflecting to the transparent state was investigated in detail. As a main result, the threshold intensity turns out …

Poly(3-Alkylthiophene) Modifications, A. Bolognesi

Turkish Journal of Chemistry

No abstract provided.

Some Recursive Relationships Between Acenes And Cyclacenes, Lemi Türker

Turkish Journal of Chemistry

Some structural relationships between acenes and cyclacenes both H\\"{u}ckel- and Mobius-type and within the same class of compounds were demonstrated by the recursive analysis of their $E_{\pi}$ and $I_{\pi}$ values or the first differences thereof. It was found that the first differences of $E_{\pi}$ and $I_{\pi}$ tend to have certain limit values as the number of benzenoid rings increases in each class of compounds studied.

The Removal Of Organic Sulfur From Two Turkish Lignites By Chlorinolysis, Yücel Y. Kadioğlu, Semra Karaca, Samih Bayrakçeken, M. Şahin Gülaboğlu

Turkish Journal of Chemistry

The removal of organic sulfur from two Turkish lignites by chlorinolysis with chlorine gas in water and water-carbon tetrachloride media at ambient pressure was examined. The effects of stirring speed (5-20 s^{-1}), particle size (250-425, 150-180 and 74-88 \mu m), temperature (13-70°C) and time (0-10800 s) were investigated. Significant portions of the organic sulfur in the coal samples were removed.

Reaction Of 3,4-Diformyl-2,5-Dimethylpyrrole With 1,2(Substituted)Diphenyl-1,2-Diaminoethanes, Cemil Öğreti̇r, Fatma Severcan

Turkish Journal of Chemistry

3,4-Diformyl-2,5-dimethylpyrrole (1) reacts with 1,2-diphenyl-1,2-diamine derivatives to form the potentially tautomeric 2:2 macrocyclic adduct (1)=(1). ^1H and ^{13}C n.m.r. spectral data along with acidity measurements indicate that the 2-azafulvene structure (7) is predominant for all adducts.

Potentiometric Titrations Of Semicarbazone Derivatives 6-Keto 9-17 Mono Methyl Substituted Octadecanoic Acids In Non-Aqueous Media, Mustafa Yalçin, Süleyman Tanyolaç, İrfan Kizilcikli, Aydın Tavman

Turkish Journal of Chemistry

The pK$_a$ values of 6-semicarbazone 9-17 monomethyl substituted octadecanoic acids were determined using the potentiometric titration method. 2-Propanol was used as the non-aqueous medium and tetrabutylammonium hydroxide (TBAH) as the titrant in the experiments. The contribution of semicarbazone and methyl groups to the pK$_a$ values of octadecanoic acids was investigated and evaluated. In addition, observations were made on the IR spectra of the compounds.

Voltammetric Determination Of Salbutamol Based On Electrochemical Oxidation At Platinum And Glassy Carbon Electrodes, Niyazi Yilmaz, Sibel A. Özkan, Bengi Uslu, Zühre Şentürk, İnci Bi̇ryol

Turkish Journal of Chemistry

The oxidative behavior of salbutamol was studied as a function of pH at platinum and activated glassy carbon electrodes. Between pH 1.9 and 12.0, the drug was characterized by a single oxidation step at both electrodes. The process was found to be dependent on the nature and the pH of the supporting elctrolyte. The procedure yielded a linear concentration range of $1 \times 10^{-4}$ to $1 \times 10^{-3}$ M and $2 \times 10^{-5}$ to $1 \times 10^{-3}$ M in 0.2 M sulphuric acid and a phosphate buffer of pH 6, at platinum and glassy carbon electrodes, respectively. The method was …

Synthesis And Characterization Of Amorphous-Liquid Crystalline Poly(Vinyl Ether) Block Copolymers, İ. Ersin Serhatli, Müge Serhatli

Turkish Journal of Chemistry

A new series of amorphous-liquid crystalline poly(vinyl ether) block copolymers was synthesized using living cationic polymerization and free-radical polymerization techniques. Vinyl ether monomer was polymerized using a trifluoromethane sulfonic acid and methyl triflouoromethanesulfonate/tetrahydrothiophene initiator system in dichloromethane at -18^oC, and quantitatively terminated with labile azo compounds in order to obtain poly(vinyl ether) with well-defined molecular weight and end groups. This polymer was used in a subsequent blocking step in which azo groups were decomposed at 80^oC in the presence of methyl methacrylate and styrene monomer. In both copolymers, blocks of different chemical composition were segregated in the solid and melt-phase …

Electrochemical Polymerization And Analysis Of Some Aniline Derivatives, Bekir Sari, Muzaffer Talu

Turkish Journal of Chemistry

In this study, conductive homopolymers of o-chloroaniline, p-bromoaniline and N-methylaniline were synthesized electrochemically in perchloric acidic solution and their properties were analyzed. Initially, the maximum oxidation potential values of these monomer solutions were determined by Cyclic Voltammetry (CV). Their conductive polymers were then synthesized under a nitrogen atmosphere using a potentiostat. FTIR spectra were taken in order to analyze the structural properties of the resulting polymers. Thermogravimetric analysis (TGA) was conducted and surface micrographs were taken by a Scanning Electron Microscope (SEM). The conductivity levels of the polymers were determined by the Four Probe technique. Magnetic properties of the samples …

Electron Spectroscopy For Material Characterization, Ş. Süzer

Turkish Journal of Chemistry

Basic principles of the two electron spectroscopic techniques, the x-ray photoelectron spectroscopy, XPS, and the Auger electron spectroscopy, AES, are given. Their utilization in material characterization are introduced through examples with application of these techniques to various surface related problems.

Separation Of Molybdenum, Vanadium And Nickel By Liquid-Liquid Extraction, T. Coşar, R. Zi̇yadanoğullari

Turkish Journal of Chemistry

Elements in the ash of asphaltites that is used in thermal central for power generation units are Mo, V, U, Ti and Ni. The main goal of this study was to separate molybdenum, vanadium and nickel from the aqueous solution. The quantities of the above elements in solution were in the range of 50-80 ppm. The separate these elements from solution, the liquid-liquid extraction method was applied to samples. Alamine 336 was used as extractant. During the reduction-oxidation processes, single and multiple extraction methods were applied to the solution in combination. The quantities of molybdenum, vanadium and nickel in the …

Potentiometric Investigation Of The Effects Of Several Substituents On The Basicity Of Benzilidene-O-Hydroxyaniline, Esma Kiliç, Orhan Atakol, E. Canel, Zehra Ali̇beşeoğlu, Turgut Gündüz, Fitnat Köseoğlu

Turkish Journal of Chemistry

Chloro-, bromo-, iodo-, nitro-, methoxy- and hydroxy-substituted benzilidene-o-hydroxyaniline were prepared in order to investigate the effects of substituents on the basicity of benzilidene-o-hydroxyaniline. For each substituent, three isomers -- ortho, meta and para -- were synthesised. Schiff bases were titrated potentiometrically with perchloric acid in nitrobenzene solvent at $25^{\circ}$C. All compounds gave well-shaped titration curves, from which half-neutralisation potentials were calculated. The trend in the values of half-neutralisation potentials of Schiff bases were explained in terms of the nature of the substituents. The applicability of the Hammett equation to the effect of substituents in Schiff bases in nitrobenzene solvent was …

On The Türker Angles In The Theory Of Total \Pi-Electron Energy, Ivan Gutman

Turkish Journal of Chemistry

The Türker angles $\theta, \alpha$ and $\beta$ are quantities invented by Lemi Türker, and are used in the theory of total $\pi$-electron energy $(E)$ of unsaturated conjugated hydrocarbons. We report here expressions for $\theta, \alpha$ and $\beta$ in terms of $E$ and the parameters $n$ (= half the number of carbon atoms) and $e$ (= the number of carbon-carbon bonds). The forms of these expressions are remarkably similar. Numerical calculation performed on a representative set of benzenoid hydrocarbons reveals that the dependence of the angles $\alpha$ and $\beta$ on molecular structure is very similar, and that their ratio is almost …

Synthesis Of New Bisamidoxime Ligands And Their Monocharged Metal Complexes, Niyazi Biçak, Tülay Atay

Turkish Journal of Chemistry

This paper describes the synthesis of two new bisamidoxime ligands with dithioether connecting groups. The ligands were obtained from ethane dithiol in two steps; i) cyanoalkylation ii) oximation with hydroxylamine. Cyanoalkylation of ethanedithiol was carried out by condensing with chloro acetonitrile and base-catalysed addition of acrylonitrile, yielding bis(cyanomethylthio) ethane and bis(cyanoethyl thio) ethane, respectively. Upon subsequent oximation with hydroxylamine, these bisnitrile compounds gave corresponding bis(amidoxime) ligands in reasonable yields. The ligands behave as tetradentate ligands and on interaction with Cu(II), Ni(II), Co(II) chlorides produces monocharged metal complexes in a [ML]$^+$Cl$^-$ composition.

Remote Sensing Of Commercial Aircraft Emissions, Peter J. Popp, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Heavy-Duty Diesel Truck Emissions In The Austin- San Marcos Area: August 1998, Jerome A. Morris, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Determination Of Trace Levels Of Lead In Whole Blood By Graphite Furnace Atomic Absorption Spectroscopy, Leslie A. Sombers

Dissertations, Theses, and Masters Projects

No abstract provided.

Preparation And Structures Of Crystalline Aromatic Cation-Radical Salts. Triethyloxonium Hexachloroantimonate As A Novel (One-Electron) Oxidant, Rajendra Rathore, A. S. Kumar, Sergey V. Lindeman, Jay K. Kochi

Chemistry Faculty Research and Publications

Triethyloxonium hexachloroantimonate [Et₃O⁺SbCl₆^-] is a selective oxidant of aromatic donors (ArH), and it allows the facile preparation and isolation of crystalline paramagnetic salts [ArH^+•, SbCl₆^-] for the X-ray structure determination of various aromatic cation radicals. The mechanistic relationship between the Meerwein salt [Et₃O⁺SbCl₆^-] and the pure Lewis acid oxidant SbCl₅ is based on a prior ethyl transfer from oxygen to chlorine within the ion pair.

The CuA Center Of A Soluble Domain From Thermus Cytochrome Ba3. An Nmr Investigation Of The Paramagnetic Protein. A Proton Nmr Study Of The Paramagnetic Active Site Of The CuA Variant Of Amicyanin, Richard C. Holz

Chemistry Faculty Research and Publications

No abstract provided.

A Computational Study Of M-M Multiple Bonding In Ph2mmph2N-, Where M = B Or Al, And N = 0, 1, Or 2, Edward L. Hamilton, Justin G. Pruis, Roger L. Dekock, Karl J. Jalkanen

University Faculty Publications and Creative Works

We have completed Hartree-Fock ab initio electronic structure calculations on the series of compounds Ph2MMPh2n, where M = B or Al, and n = 0, 1-, or 2-. The results show that the added one and two electrons upon reduction of the neutral compounds go into the M-M π bond, as expected. The canting of the rings in D2 symmetry is related to the degree of steric repulsion in the compounds. There is no evidence for preferential population of an Al-Al σ* orbital in the dianion of the aluminum compound, and hence we have no ready explanation as to why …

Reactions Of Modified Silica Gel Surfaces With Organometallic Compounds: Enhancing Olefin Polymerization Catalysts, Richard E. Diebel Iii

Masters Theses

Pretreated silica gels with distinct silica surfaces containing either isolated silanols, vicinal silanols, siloxanes, or some combinations of the three, were reacted with several organometallic compounds to determine how each compound reacted with the different silica surface species. The organometallic compounds used were trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, methylaluminoxane, dibutylmagnesium, and bis-cyclopentadienyl dimethyl zirconium.

These reacted silica gels were analyzed using diffuse reflectance infrared Fourier transform spectroscopy and ICP-AES elemental analysis. CH/Metal ratios were calculated using specific peaks in the IR spectra to elucidate the surface bonded species. Elemental analysis was used to determine how much metal was bonded …

Characterization Of Petroleum Fog Oil And Vegetable Oil Smokes, Andrew Oliver Larouche

Masters Theses

"Deception and concealment to gain tactical advantage in the battlefield has been an integral part of warfare. Smoke has been a common tool used for signaling, concealment of troop movement and weapon deployment. U.S. Armed Forces have made use of smokes in an organized manner since the 1st world war. Since then various materials such as white phosphorus, zinc chloride, diesel fuel and petroleum oil aerosols have been used to obscure military targets. For the past thirty years fog oil (FO) a medium distillate has been extensively used by the U.S. Armed Forces for generation of obscurant smokes (OS). During …

Inactivation Of Soybean Peroxidase During Sodium Azide Oxidation: A Comparative Study, Mohamed Yehia Zakaria Aboul Eish

Dissertations and Theses @ UNI

Azide ion is a mechanism-based inactivator of a number of peroxidases. However, there are often variations in the manner in which inactivation occurs. Soybean Peroxidase (SBP) is found in the plant's seed coat. Unlike many other peroxidases, a single enzyme rather than several isozymes are produced thus making more simple the purification and characterization of the enzyme. In this research it was shown that, as with other peroxidases, SBP is inactivated by azide during turnover. During azide oxidation SBP forms a ferrous-NO intermediate. In this respect, SBP is similar to the lignin peroxidases from Phanerochaete chrysosporium which also form ferrous-NO …