Chemistry Commons^™

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.

A Kinetic Study Of The Photolysis Of Ethylferrocene In Chloroform, Son L. Phan, Patrick E. Hoggard

Chemistry and Biochemistry

The photooxidation of ethylferrocene to ethylferricinium ion and tetrachloroferrate in CHCl3 under 254 nm irradiation proceeds through light absorption by both ethylferrocene and chloroform. The products remain in solution at concentrations below 10-3 M. The fraction occurring through a solvent-initiated pathway increases during the course of the reaction. A secondary thermal reaction is responsible for generating tetrachloroferrate from ethylferricinium ion. The rate of the reaction increases during the early stages, and the data throughout the course of the reaction are consistent with the rate law ( afs + bfR)/ (1 + c[R]/[P]-d[R]/[Cl ]), where [R] and [P] are the concentrations …

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 …

Electropolymerization Of Thiophene With And Without Aniline In Acetonitrile, Muzaffer Can, Kadir Pekmez, Nuran Pekmez, Attila Yildiz

Turkish Journal of Chemistry

The electrooxidation behaviors of thiophene and 3-methylthiophene on a Pt surface in acetonitrile/tetrabutylammonium tetrafluoroborate solution were investigated using cyclic voltammetry. The electropolymerization of these monomers and electrochemical properties of polythiophene and poly(3-methylthiophene) were studied in neutral, acidic and basic media. Mechanisms related to the formation of polymers and electroactivity loss were proposed. The effect of thiophene on the electropreparation and properties of polyaniline were also investigated. The presence of thiophene in solutions of aniline in acetonitrile accelerates the formation and causes an improvement in the conductivity of polyaniline films. Thiophene, which catalyzes the polyaniline formation, enters into the structure of …

Xps Investigations On Conducting Polymers, Ş. Süzer, Ö. Bi̇rer, U.A. Sevi̇l, O. Güven

Turkish Journal of Chemistry

X-ray photoelectron spectroscopy, XPS, was used for the characterization of electrically conducting polymeric materials. In the spectrum of polypyrrole, PPy, the Nls region exhibits two peaks, at 402.0 and 399.8 eV, corresponding to -N$^+$- and -N- moieties, respectively. The intensity of the N$^+$ peak decreases as the material loses its conductivity, hence the ratio of the experimentally derived N$^+$/C atomic ratio correlates exponentially with the measured conductivity. A similar observation also exists between the F$^-$/C atomic ratio both in polypyrrole and polythiophene. In the XPS spectrum of the composite material prepared using polyaniline, PAN and polyvinylchloride, PVC, two different kinds …

Electrochromism Of Sol-Gel Derived Niobium Oxide Films, M. Maçek, B. Orel

Turkish Journal of Chemistry

Niobium oxide films are promising cathodic electrochromics that in many aspects can compete with the more frequently studied WO$_3$ films. The films reported herein were prepared using the sol-gel route from a NbCl$_5$ precursor. The electrochromic properties were pronounced for crystalline films that are heat-treated at 500^oC and exhibited transmittance changes between coloured and bleached states of 60 \% in the UV and 80 \% in the VIS-NIR regions. Improved bleaching and more reversible electrochromism of thick niobium oxide films (d $>$ 250 nm) were obtained by lithiation.

Polymerization Of Pyrrole And Thiophene On Polyethylene Adipate Electrodes, Seyfettin Erturan, Burcu Yalvaç, Sena Toraman

Turkish Journal of Chemistry

Polymerizations of pyrrole and thiophene on a platinum foil coated by polyethylene adipate (PEA) were carried out in acetonitrile by electrochemical methods. Different compositions of semi-conducting composite films of PEA/Polypyrrole(PPy), PEA/Polythiophene(PT) were prepared by the electrochemical polymerization of pyrrole and thiophene on PEA electrode. The polymerization was possible only for a certain thickness of the polyethylene adipate(PEA) on the platinum. Conductivities of PEA/PPy, PEA/PT, films at different compositions were obtained. The films were examined by FTIR spectroscopy. The topography of surface films were analyzed by a scanning electron microscope(SEM). The conductivity behaviour of (PEA/PPy), (PEA/PT) films at different compositions when …

Cu And Pb Adsorption On Some Bentonitic Clays, Oğuz İnel, Fehmi Albayrak, Ayşgül Aşkin

Turkish Journal of Chemistry

Cu$^{2+}$ and Pb$^{2+}$ adsorption isotherms were measured on some clay samples obtained from various regions of Turkey. Also specific surface areas of clays were determined from adsorption data of ortho-phenanthroline(OP). The adsorptions of ions and OP were studied using the batch equilibration technique as a function of adsorbate concentration. The adsorption data, over the whole range of concentrations used, follow the Langmuir adsorption isotherm. The retention capacities of the adsorbates and the cation exchange capacities of the clays were determined. Plots of K$_d$, the distribution coefficient of ions between the solid and solution phases, vs. $\Gamma$, the surface density of …

Optimization Of Starting Time And Period Of Induction And Inducer Concentration In The Production Of The Restriction Enzyme Ecori From Recombinant Escherichia Coli 294, Candan Yildir Tamerler, Z. İlsen Önsan, Betül Kirdar

Turkish Journal of Chemistry

Induction parameters including inducer concentration, period of induction and the cell concentration at which inducer is to be added to the fermentation broth were optimized in order to increase the yield of the {\em Eco}RI restriction endonuclease isolated from recombinant {\em E. coli}. Bacterial cells harboring the plasmid pPG430 containing {\em Eco}RI endonuclease and the methylase genes under the control of {\em lac} promoter were used in the experiments where induction was accomplished by using lactose isopropyl-$\beta$-D-thiogalactoside (IPTG). An IPTG concentration of 0.1mM, the late exponential phase of growth (at an optical density of 1.2 at 595 nm) and an …

Gas Chromatography In The Low Concentration Determination Of Nitrous Oxide And Volatile Anaesthetics, Ahmet Uyanik

Turkish Journal of Chemistry

A previously reported single-column gas chromatographic separation method was modified for dual-detection gas chromatography (TCD+FID) and evaluated for the low concentration analysis of volatile anaesthetics (halothane, isoflurane) and nitrous oxide. It was found that no serious problem occurs in the determination of volatile anaesthetics with FID ($

Crystal Structure Of Dichlorodiaquabis-(P- Dimethylaminobenzaldehyde)Manganese(Ii), Veysel T. Yilmaz, Turan K. Yazicilar, Halis Ölmez, R. Alan Howie

Turkish Journal of Chemistry

The crystal structure of dichlorodiaquabis-($p$-dimethylaminobenzaldehyde)manganese(II), [MnCl$_2$(OH$_2$)$_2$(C$_9$H$_{11}$NO)$_2$], was determined from X-ray intensity data. The structure consists of the isolated molecules of the complex. The central Mn atom in the complex is coordinated by txo $p$-dimethylaminobenzaldehyde and two water molecules and also two chlorine atoms, resulting in a distorted octahedral environment. The same molecules or ions occupy {\it trans} positions. The crystal structure is stabilized by weak hydrogen bonds present between the isolated molecules.

Thermal Behaviour Of Some Azo Dyes Containing Sterically Hindered And Water-Soluble Groups, Hasan Kocaokutgen, Zerrin Heren

Turkish Journal of Chemistry

Thermal behaviour of six azo dyes containing steric hindered groups such as tert-butyl, sec-butyl and isopropyl, were investigated by means of thermogravimetry (TG), differential thermal analysis (DTA) and differential thermogravimetry (DTG). The thermal decomposition points and amount of volatile pyrolysis products, were determined in nitrogen atmosphere using TG, DTA and DTG curves.

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 …

Mechanistic Studies Of Cation Photogeneration, Mary Frances Clifton

Dissertations

No abstract provided.

Metathesis-Based Synthesis Of Jasmonate And Homojasmonate Lactones, Candidates For Extracellular Quorum Sensing Molecules In Candida Albicans, Su C. Cho, Patrick Dussault, Amber D. Lisec, Ellen C. Jensen, Kenneth W. Nickerson

Department of Chemistry: Faculty Publications

Ring-closing metathesis of jasmonate esters is shown to provide a rapid entry to jasmonate lactones. The lactones were investigated as possible quorum sensing molecules for the fungi Candida albicans. Assays demonstrated no effect on fungal morphology at concentrations up to 96 mM.

Substituted Polythiophenes From Highly Reactive Zinc Reagents, Reuben D. Rieke

Department of Chemistry: Faculty Publications

A novel Zerovalent zinc species and an organozinc reagent are disclosed. The zerovalent zinc species is directly pro duced by reaction of a reducing agent on a zinc salt, preferably Zn(CN)₂. The organozinc reagent results from the reaction of the zerovalent zinc species and an organic compound having one or more stable anionic leaving groups. These organozinc reagents include a wide spectrum of functional groups in the organic radical, and are useful in a variety of reactions schemes.

Cross-Coupling Of Organic Compounds Using Cuprous Odide, Reuben D. Rieke

Department of Chemistry: Faculty Publications

Cross-coupling or addition reactions of organic compounds, including acid halides, allylic halides, and C.B-unsaturated carbonyl containing compounds, with organozinc com pounds may be readily and Safely carried out in the presence of cuprous iodide. The use of this catalyst in the coupling reaction provides for the preparation of commercially useful products in the pharmaceutical, agrochemical and other industries.

Ab Initio And Dft Investigations Of Lithium/Hydrogen Bonded Complexes Of Trimethylamine, Dimethyl Ether And Dimethyl Sulfide, Salai Cheettu Ammal, P. Venuvanalingam

Faculty Publications

Ab initio and DFT computations have been carried out on LiF and HF complexes of a set of n-donors viz. trimethylamine, dimethyl ether and dimethyl sulfide with a 6-31++G(d,p) basis set. The effect of correlation has been included with MP2, MP4 and DFT calculations. NBO analyses of the wavefunctions have been performed to examine the intermolecular interaction at the orbital level. Calculations reveal that these donors form strong n→σ* complexes and computed binding energies of the (CH₃)₂O···HF complex agree very well with the experimental binding energies from IR spectroscopy. LiF forms stronger complexes than HF, …

Electroanalysis Using Differential Pulse Methods At A Microelectrode, Enda Howard, John Cassidy, John O'Gorman

Articles

This communication characterises the differential pulse voltammetric response of ultramicroelectrodes in connection with two different models

Paramagnetic Nuclear Magnetic Resonance (Nmr) Studies On The Calcium Binding Site Of [Alpha]-Lactalbumin, Thomas Kurt Ritter

Dissertations and Theses

Paramagnetic NMR has drawn interest as a technique for extending the range of systems that can be investigated. The purpose of this study was to determine whether a combination of paramagnetic two-dimensional and relaxation techniques allows for assigning resonances corresponding to residues forming the metal binding site of proteins in which the metal is coordinated exclusively by amino acid side chains and which have been previously inaccessible to assignment.

α-Lactalbumin (LA) is a calcium binding protein with relatively broad NMR signals; this broadness has prevented complete assignment. LA has been the subject of many studies, because it can form a …

Novel Synthetic Route To 5-Substituted Indoles, Helen Y. Chen

Master's Theses

No abstract provided.

Photoinduced Coupling Of Acetylenes And Quinone In The Solid State As Preorganized Donor−Acceptor Pairs, E. Bosch, S. M. Hubig, Sergey V. Lindeman, Jay K. Kochi

Chemistry Faculty Research and Publications

Crystalline electron donor−acceptor (EDA) complexes of various diarylacetylenes (DA) and dichlorobenzoquinone (DB) are isolated and structurally characterized by X-ray crystallography. Deliberate excitation of either the DB acceptor at λ_DB = 355 nm or the 1:2 [DA, 2DB] complex at λ_CT = 532 nm in the solid state leads to [2 + 2] cycloaddition and identical (isomeric) mixtures of the quinone methide products. Time-resolved (ps) diffuse reflectance spectroscopy identifies the ion-radical pair [DA^•+, DB^•-] as the reactive intermediate derived by photoinduced electron transfer in both photochemical …

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.

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.

Disproportionation And Structural Changes Of Tetraarylethylene Donors Upon Successive Oxidation To Cation Radicals And To Dications, Rajendra Rathore, Sergey V. Lindeman, A. S. Kumar, Jay K. Kochi

Chemistry Faculty Research and Publications

The stepwise (one-electron) chemical oxidation of the tetraphenylethylene donor and its substituted analogues (D) can be carried out by electron exchange with aromatic cations or antimony(V) oxidants to selectively afford the cation radical (D^+•) initially and then the dication (D²⁺). The ready interchange of the latter establishes the facile disproportionation (i.e., 2D^+• ⇌ D²⁺ + D) that was originally examined by only transient electrochemical techniques. The successful isolations of the crystalline salts of the tetraanisylethylene cation radical (1^+•) as well as the …

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 …

Bioremediation Of Soil Contaminated With Explosives, Catherine A. Axtell

Dissertations and Theses @ UNI

Bioremediation of contaminated soil and water has been the topic of considerable research interest. White rot fungi have recently been proposed for use in biodegradation of explosives. The explosives, TNT, RDX and HMX are integral components of the manufacture of munitions. The wastes from the production of these and other explosives have been discharged into the surrounding environment resulting in contamination. Phanerochaete chrysosporium and strain F600, a proprietary white rot fungus developed by Mycotech Corporation, were studied with regard to their ability to degrade TNT, HMX and RDX in liquid cultures and in soil. Laboratory studies demonstrated that P. chrysosporium …