Chemistry Commons^™

Determination Of Trace Copper By Faas After Solid Phase Extraction And Preconcentration Onto Amberlite Xad-2 Loaded With Nitroso-R Salt, Mohammad Ali Taher, Sayed Ziae Mohammadi Mobarakeh, Ali Reza Mohadesi

Turkish Journal of Chemistry

A procedure for the separation and preconcentration of trace amounts of copper is proposed. It is based on the adsorption of copper(II) ions solution onto a column of Amberlite XAD-2 resin loaded with disodium 1-nitroso-2-naphthol-3, 6-disulfonate (nitroso-R salt). Copper is quantitatively retained on the column in the pH range 5.5-7.8 at a flow rate of 2 mL min^{-1}. The copper complex eluted with 5 mL of dimethylformamide (DMF) and copper was measured by flame atomic absorption spectrometry (FAAS) at 324.8 nm. In this case, 0.10 \mu g of copper can be concentrated in the column from 800 mL of aqueous …

Synthesis And Antimicrobial Evaluation Of Some New 2-(2-(P-Chlorophenyl) Benzimidazol-1-Yl Methyl)-5-Substituted Amino-[1,3,4]-Thiadiazoles, Gülgün Ayhan Kilcigi̇l, Canan Kuş, Nurten Altanlar, Süheyla Özbey

Turkish Journal of Chemistry

Some 2-(2-(p-chlorophenyl)benzimidazol-1-ylmethyl)-5-substituted amino-[1,3,4]-thiadiazoles were synthesized and their in vitro antimicrobial activities were tested against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Candida albicans and Candida krusei. Compounds 1b and 12b which possess remarkable activity against C. albicans and marginal activity against C. krusei were found to be the most active compounds in this series. Single crystal X-ray diffraction analysis was performed for compound 8b.

Examination Of Some Organic Explosives By Ion Mobility Spectrometry (Ims), Hülya Koyuncu, Ertan Seven, Ayla Çalimli

Turkish Journal of Chemistry

The increase in terrorist activities committed using explosives in recent years has generated the need for improved analytical methods that can accurately and quickly identify explosives and their residues. In this study such an analytical method is evaluated. In the first phase of the study, standard solutions and a standard mixture solution of TNT (2,4,6-trinitrotoluene), RDX (1,3,5-trinitro-1,3,5-triazocyclohexane), PETN (pentaerythritoltetranitrate) and TETRYL (2,4,6-trinitrophenylmethylnitramine) were examined using ion mobility spectrometry (IMS). In the second phase, qualitative analysis of a real explosion residue was carried out and the explosive material used in the bomb was identified by analysing the acetone extract. In the …

Synthesis, Spectral And Thermal Investigations Of Some Oxovanadium(Iv) Complexes Of Hydrazones Of Isonicotinic Acid Hydrazide, Ram K. Agarwal, Lakshman Singh, Deepak K. Sharma, Ritu Singh

Turkish Journal of Chemistry

A new series of 12 complexes of oxovanadium(IV) with hydrazones of isonicotinic acid hydrazide, namely N-isonicotinamido-3',4',5'-trimethoxybenzalaldimine (INH-TMB) and N-isonicotinamido-2'-furanaldimine (INH-FUR) with the general formula VOX_2.nL (X = Cl, Br, I, NCS, NO_3, n = 1; X = ClO_4, n = 2; L = INH-TMB or INH-FUR) were synthesized and characterized on the basis of analytical, conductance, molecular weight, magnetic moment, infrared and electronic spectral data. The infrared data of the complexes reveal the bidendate nature of both ligands and coordination to carbonyl-oxygen and azomethinic-nitrogen atoms. The probable coordination number of the central metal is 5. Thermal stabilities of the complexes …

Phlinoside F, A New Phenylethanoid Glycoside From Phlomis Angustissima, Funda Nuray Yalçin, Tayfun Ersöz, Erdal Bedi̇r, Sevser Şahpaz, François Bailleul, Ikhlas A. Khan, Ali̇ Arslan Dönmez, İhsan Çaliş

Turkish Journal of Chemistry

From the overground parts of Phlomis angustissima, a new phenylethanoid triglycoside, \beta-(3-hydroxy,4-methoxyphenyl)ethyl- O-[\beta -xylopyranosyl(1 \to 2)-\alpha -rhamnopyranosyl-(1 \to 3)] -O-4-O-feruloyl-\beta -glucopyranoside, named phlinoside F, was isolated along with the known compounds alyssonoside, samioside, lamiide, auroside, naringenin, and syringaresinol-4-O-\beta -D-glucopyranoside. The structure of the new glycoside was elucidated by spectroscopic methods.

Voltammetric, Uv Absorption And Viscometric Studies Of The Interaction Of Norepinephrine With Dna, Mehmet Aslanoğlu, Necla Öge

Turkish Journal of Chemistry

Voltammetric, UV-vis spectroscopic and viscometric methods were used to investigate the interaction between norepinephrine and DNA. The results of square wave voltammetric and UV-absorption measurements have shown that norepinephrine was bound to DNA. Besides the electrostatic interaction between DNA and norepinephrine, hydrogen bonds and intercalation may also exist. Viscosity measurements also suggest that NE is bound to DNA via an electrostatic mode of interaction at lower norepinephrine concentrations. However, at higher concentrations of norpinephrine, the increase in the relative viscosity of DNA indicated that the intercalation is also involved in the binding. The binding constant and the binding site size …

Development Of Gold Porous Plate Electrode And Examination Of Its Performance For Iodine Determination, Ülkü Anik Kirgöz, Hüseyi̇n Tural

Turkish Journal of Chemistry

A novel procedure for the construction of a home-made gold porous plate electrode is described. A plate of silver and gold alloy was treated with nitric acid or alternatively by anodic oxidation to remove the silver component, leaving a porous surface having active sites for adsorption. The performance of the electrode developed was tested using iodine solution as analyte material. The parameters related to the working conditions were optimized before the examination of analytical characteristics. Under the optimal conditions, the voltammetric results show that the gold porous plate electrode offers the detection limit of 2.18 x 10^{-5} M and reproducibility …

A New Approach To The Ring Opening Reactions Of 2,7,7-Trimethyl-3,3-Dibromotricyclo[4.1.1.0^{2,4}]Octane, Zeki̇ Şenol, Ömer Zai̇m, Meti̇n Balci

Turkish Journal of Chemistry

The reaction of \alpha-pinene and dibromocarbene produced a fairly unstable product, 2,7,7-trimethyl-3,3-dibromotricyclo[4.1.1.0^{2,4}]octane, from which 3-bromo-7,7-dimethyl-2-methylenebicyclo[4,1,1]oct-3-ene and 3-bromo-2,7,7-trimethylbicyclo [4,1,1]octa-2,4-diene were obtained in chloroform at room temperature and in various other media and conditions. Two new compounds, 3-bromo-2,7,7-trimethylbicyclo [4.1.1]oct-3-en-2-ol and 2-(4-bromo-5-methylcyclohepta-3,5-dien-1-yl) propan-2-ol, were observed in aqueous acetone in addition to the previous two. The stability and formation mechanism of the formed products are discussed

Triterpene Saponins From Nigella Sativa L., Mustafa Kemal Taşkin, Özgen Alankuş Çalişkan, Hüseyi̇n Anil, Hassan Abou-Gazar, Ikhlas A. Khan, Erdal Bedi̇r

Turkish Journal of Chemistry

Three known triterpene glycosides were isolated from the MeOH extract of dried and powdered seeds of Nigella sativa. The structures of the compounds were established as 3-O-[\beta-D-xylopyranosyl- (1 \to 3)-\alpha-L-rhamnopyranosyl-(1 \to 2)-\alpha -L-arabinopyranosyl]- 28-O-[\alpha-L-rhamnopyranosyl-(1 \to 4)-\beta-D-glucopyranosyl-(1 \to 6)- \beta-D-glucopyranosyl]-hederagenin (1), 3-O-[\alpha -L-rhamnopyranosyl- (1 \to 2)-\alpha-L-arabinopyranosyl]-28-O-[\alpha -L-rhamnopyranosyl-(1 \to 4)- \beta-D-glucopyranosyl-(1\to 6)-\beta-D-glucopyranosyl]-hederagenin (2), and 3-O-[\beta-D-xylopyranosyl- (1\to 3)-\alpha-L-rhamnopyranosyl-(1\to 2)-\alpha- L-arabinopyranosyl]-hederagenin (3) by means of chemical and spectral methods. Compound 2 was isolated for the first time from the genus Nigella.

The Crystal And Molecular Structure Of New Hydrogen Dinitrate Of Nitrato(2,2',2''-Terpyridyl)Platinum(Ii) Ion, [Pt(Terpy)Ono_2][H(Ono_2)_2], Abdurrahman Şengül

Turkish Journal of Chemistry

The title compound, C_{15}H_{12}N_6O_9Pt, consists of [Pt(terpy)ONO_2]^+ cation and [H(ONO_2)_2]^- anion, in which 2 nitrate groups are linked by a strong hydrogen bond [O \cdots O 2449(1) Å]. In the cation, the terpyridine is coordinated to Pt as a tridentate ligand and the fourth position is occupied by the nitrate ion's oxygen. The coordination around Pt is square-planar. The coordinated nitrate moiety adopts a distorted trigonal-planar configuration. It belongs to the space group P \bar{1} with a = 8.605(2), b = 10.220(3) Å, c = 10.517(2) Å and \alpha = 89.51(1), \beta = 82.78(2), \gamma = 76.90(2)°.

Synthesis, Characterization And Genotoxicity Of Platinum(Ii)Complexes With Subtituted Benzimidazole Ligands, Özteki̇n Algül, Berri̇n Özçeli̇k, Ufuk Abbasoğlu, Fatma Gümüş

Turkish Journal of Chemistry

Five Pt(II) complexes with the ligands 2-ethyl-/ or-benzyl-/ or-phenoxymethyl- and 1-methyl-2-hydroxymethyl- and 1-methyl-2-phenyl- benzimidazoles were synthesized and characterized by elemental analysis, and IR and ^1H-NMR spectra and evaluated for their in vitro genotoxic activities by Rec-Assay test. Based on the data obtained in this study, the Pt(II) complexes tested might be taken into consideration as promising antitumor compounds.

Metathesis Key In Production Of Pharmaceuticals, Plastics, Aldemaro Romero Jr., Michael J. Panigot

Publications and Research

No abstract provided.

Studies Of Unusual Packing And Of Polymorphism In Two Crystal Systems, Xiang Hao

University of Kentucky Doctoral Dissertations

Crystal structures of anhydrous pinacol, the hexagonal pinacol, pinacol monohydrate, and pinacol hexahydrate were studied. In all the structures crystal packing is unusual and complicated. The origin of the complexity may be the difficulty in filling space densely and while also satisfying the H-bonding requirements when the molecule has few internal degrees of freedom.

Five 15-crown-5 complexes of M(NO₃)₂ (M = Cu, Zn, Mg, Co, Mn) were synthesized and characterized using X-ray diffraction and differential scanning calorimetry. The system is rich in polymorphs. Nine definite solid-state phases were identified. More phases probably exist in the solid state …

Crystal Structure Of The Gtpase Domain Of Rat Dynamin 1, Thomas F. Reubold, Susanne Eschenburg, Andreas Becker, Marilyn Leonard, Sandra L. Schmid, Richard B. Vallee, F. Jon Kull, Dietmar J. Manstein

Dartmouth Scholarship

Here, we present the 1.9-A crystal structure of the nucleotide-free GTPase domain of dynamin 1 from Rattus norvegicus. The structure corresponds to an extended form of the canonical GTPase fold observed in Ras proteins. Both nucleotide-binding switch motifs are well resolved, adopting conformations that closely resemble a GTP-bound state not previously observed for nucleotide-free GTPases. Two highly conserved arginines, Arg-66 and Arg-67, greatly restrict the mobility of switch I and are ideally positioned to relay information about the nucleotide state to other parts of the protein. Our results support a model in which switch I residue Arg-59 gates GTP binding …

Analytical And Synthetic Methods For Anatoxins., Janet Crowley

Theses

This thesis is focused on the potent cyanobacterial neurotoxins anatoxin-a (AN), its methyl analogue homoanatoxin-a (HMAN) and their non-toxic dihydro- and epoxydegradation products. In commencing the investigation into this area a literature review was performed in order to identify areas where more research and method development was required (Chapter 1). The review highlighted the fact that although a number of analytical methods had been developed for the analysis of AN, there were few methods for the determination of its potent homologue HMAN and their non-toxic degradation products. As these neurotoxins degrade quickly it is important to monitor their degradation products, …

Elucidation Of The Mass Spectral Fragmentation Pathways Of Cyclic Hepatopeptides Microcystins, Paloma Muniz Ortea

Theses

The most frequently found cyanobacterial toxins in blooms from fresh and brackish waters are the cyclic peptide microcystins (MCs) and nodularin family. These toxins cause fatal poisonings of agricultural livestock, wild animals, birds and fish on a worldwide basis. The involvement of these toxins in human health problems has also been inferred in several countries and their presence in drinking water sources is of interest to the drinking water industry.

One of the biggest problems in the analysis of MCs is the lack of commercially available standards to be used for the identification and characterisation of these cyanobacterial toxins. One …

Synthesis Of Alkylthiol-Containing Fluorene Derivatives For Gold Nanoparticle Functionalization, Sriram Mukundarajan

Electronic Theses and Dissertations

A novel synthetic methodology has been developed for attaching fluorene derivatives, containing different types of electron donating and accepting groups at the 2 and 7 positions, to gold nanoparticles of different sizes by exploiting the affinity of the thiol functional group for gold. The distance between the dye and nanoparticles was varied by introducing two alkyl chains containing different number of carbon atoms at the 9 position on the fluorene ring system. The methodology that was developed gave enough scope for performing Radiative Decay Engineering (RDE) studies, in order to investigate the impact of gold nanoparticles on the singlet oxygen …

Effect Of Humic Substance Photodegradation On Bacterial Growth And Respiration In Lake Water, Alexandre M. Anesio, William Granéli, George R. Aiken, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

This study addresses how humic substance (HS) chemical composition and photoreactivity affect bacterial growth, respiration, and growth efficiency (BGE) in lake water. Aqueous solutions of HSs from diverse aquatic environments representing different dissolved organic matter sources (autochthonous and allochthonous) were exposed to artificial solar UV radiation. These solutions were added to lake water passed through a 0.7-μm pore-size filter (containing grazer-free lake bacteria) followed by dark incubation for 5, 43, and 65 h. For the 5-h incubation, several irradiated HSs inhibited bacterial carbon production (BCP) and this inhibition was highly correlated with H₂O₂ photoproduction. The H_{2 …}

Capillary And Microchip Gel Electrophoresis Using Multiplexed Fluorescence Detection With Both Time-Resolved And Spectral-Discrimination Capabilities: Applications In Dna Sequencing Using Near-Infrared Fluorescence, Li Zhu

LSU Doctoral Dissertations

Increasing the information content obtainable from a single assay and system miniaturization has continued to be important research areas in analytical chemistry. The research presented in this dissertation involves the development of a two-color, time-resolved fluorescence microscope for the acquisition of both steady-state and time-resolved data during capillary and microchip electrophoresis. The utility of this hybrid fluorescence detector has been demonstrated by applying it to DNA sequencing applications. Coupling color discrimination with time-resolved fluorescence offers increased multiplexing capabilities because the lifetime data adds another layer of information. An optical fiber-based fluorescence microscope was constructed, which utilized fluorescence in near-IR region, …

Synthesis Of Symmetric And Asymmetric Water-Soluble Porphyrin Derivatives, Caroline Owendi Ongayi

LSU Doctoral Dissertations

Novel symmetric and asymmetric water-soluble tetrabenzoporphyrin are synthesized in relatively good yields. These compounds are synthesized by the condensation of butanopyrrole with several aldehydes that contain masked water solubilizing groups followed by metal insertion, oxidation and demetallation and deprotection of the masked solubilizing groups. The biological evaluation (in vitro and in vivo) studies are described in addition to the photophysical evaluations of the corresponding compounds. A novel versatile route to the syntheses of novel free-bases and metallo-benzoylbiliverdin is discussed. The treatment of metal free-dodecasubstituted porphyrin with sodium nitrite and trifluoroacetic acid at room temperature in the presence of oxygen affords …

The Determination Of Environmentally Important Metals In Marine Sediments, Linda Tyrrell

Masters

Surface sediment samples were collected at sites within the Rockall Through at water depth ranges from 700 – 2774 metres. The study area was predefined by the availability of samples. Samples were collected by the British Geological Survey during their gravity core survey undertaken in 1998. Methods were optimised and validated for lead, cadmium, chromium, copper, nickel, zinc, lithium and aluminium using atomic absorption spectroscopy following total digestion, and for mercury, using cold vapour atomic fluorescence spectroscopy following partial digestion. The measured metal concentration were normalised to Li to compensate for the influence of natural variability in the concentration of …

Characterization Of Black Deposit Associated With Rock Paintings In Little Lost River Cave, Idaho Using Pyrolysis Gc, Sarah Therese Fezzey

Master's Theses and Doctoral Dissertations

A black, shiny coating overlies rock paintings in Little Lost River Cave no. 1, located in southeastern Idaho. If this coating is the result of human activity within the cave – a condensate from cooking fires, for example – then a radiocarbon date on the coating would provide a minimum age for the underlying paintings. The work reported here was undertaken to test the assumption that the coating has an anthropomorphic origin. Using pyrolysis-gas chromatography-mass spectrometry (py-GC-MS) and thermally-assisted hydrolysis/methylation-GC-MS, we have compared samples of the black coating from Idaho to humic acid, a geologic material; an experimental cooking residue; …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix, Kenneth Czerwinski

Fuels Campaign (TRP)

This project examines inert fuels containing ZrO₂ and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO₂. Reactor physics calculations are used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10% of ²³⁹Pu. Ceramics are synthesized and characterized based on the reactor physics results. The solubility of the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, are investigated in a manner to provide thermodynamic data necessary for …

Assessment Of Rarity Of The Blackmouth Shiner Notropis Melanostomus (Cyprinidae) Based On Museum And Recent Survey Data, Martin O'Connell

Earth and Environmental Sciences Faculty Publications

Accurate knowledge of an organism's distribution is necessary for conserving species with small or isolated populations. A perceived rarity may only reflect inadequate sampling effort and suggest the need for more research. We used a recently developed method to evaluate the distribution of a rare fish species, the blackmouth shiner Notropis melanostomus Bortone 1989 (Cyprinidae), which occurs in disjunct populations in Mississippi and Florida. Until 1995, N. melanostomus had been collected from only three localities in Mississippi, but in 1995, eight new localities were discovered. We analyzed museum records of fish collections from Mississippi, Florida, and Alabama to compare sampling …

Assessment And In Vitro Repair Of Damaged Dna Templates From Forensic Stains, Ashley Hall

Electronic Theses and Dissertations

DNA extracted from biological stains is often intractable to analysis. This may due to a number of factors including a low copy number (LCN) of starting molecules, the presence of soluble inhibitors or damaged DNA templates. Remedies may be available to the forensic scientist to deal with LCN templates and soluble inhibitors but none presently exist for damaged DNA. In fact, only recently has the biochemical nature, the extent of DNA damage in physiological stains and the point at which the damage inflicted upon a particular sample precludes the ability to obtain a genetic profile for purposes of identification been …

The Effect Of Cu-Doping On The Magnetic And Transport Properties Of La₀.₇Sr₀.₃Mno₃, M. S. Kim, Jinbo Yang, Qingsheng Cai, X.-D. Zhou, William B. Yelon, Paul Ernest Parris, William Joseph James

Physics Faculty Research & Creative Works

The effects of Cu-doping on the structural, magnetic, and transport properties of La0.7Sr0.3Mn1xCuxO3 (0<=x<=0.20) have been studied using neutron diffraction, magnetization, and magnetoresistance (MR) measurements. All samples show the rhombohedral structure with the R[overline 3]c space-group from 10 K to room temperature (RT). Neutron diffraction data suggest that some of the Cu ions have a Cu3+ state in these compounds. The substitution of Mn by Cu affects the MnO bond length and Mn-O-Mn bond angle resulting from the minimization of the distortion of the MnO6 octahedron. Resistivity measurements show that a metal to insulator transition occurs for the x>=0.15 samples. The x=0.15 sample shows the highest MR([approximate]80%), which might result from the co-existence of Cu3-Cu2+ and the dilution effect of Cu-doping on the double exchange interaction

Synthesis And Nmr-Characterization Of Three Quinamide-Based Disaccharide Mimetics With Unusual Cyclohexane Twist-Conformation, Thuy Trang M. Nguyen, Paul H. Gross, Andreas H. Franz

College of the Pacific Faculty Articles

The synthesis of amide-linked disaccharide mimetics has been explored starting with carbohydrate-based amines and a protected quinic acid lactone. Benzyl-2-amino-4,6-Obenzylidene-2-deoxy-α/β-D-glucopyranose (12) and D-glucamine (14) were successfully coupled to give the corresponding quinamides (13 and 15), while the quinoylation of Oacetylated L-fucopyranosyl methylamine (7) failed. The latter was prepared from per-O-acetylL-fucopyranose via the improved multigram scale synthesis of the corresponding per-O-acetylL-fucopyranosyl cyanide (3). Compound 3 was subsequently hydrogenated to yield a mixture of compound 7 and the per-O-acetylated bis-(fucopyranosylmethyl) amine (5). The vicinal coupling constants in the NMR spectra of all quinamide products revealed considerable flexibility of the cyclohexane ring in …

Electronic To Vibrational Energy Transfer From Cl* (3 2P1/2) To N2O(Ν1): Failure Of A Simple Kinetic Mechanism, Brian Brumfield

Browse all Theses and Dissertations

Experimental kinetic studies were carried out examining the electronic to vibrational (E-V) energy transfer from spin-orbit excited Cl*(3 ²P_1/2 , 882 cm^-1) to N₂O(ν₁) (symmetric stretch 1285 cm^-1). All studies were carried out in the gas phase at room temperature (298 ± 2 K). Cl* was generated by pulsed laser photolysis of ICl at 532 nm in the presence of various mixtures of N₂O, ICl,Ar, and SO₂. Time-resolved IR signals of N₂O(ν₁) fluorescence at 7.8 μm were analyzed to obtain rate coefficients …

Bismuth Triflate Catalyzed Friedel-Crafts Acylations Of Sydnones, Jennifer Ann Fisher

Browse all Theses and Dissertations

In the present work, suitably functionalized arylsydnones were used to synthesize a variety of 4-acylsydnones and diacyl sydnones, both as potential precursors to novel sydnoquinolines.The approach to the diacyl species is based on the discovery that activated sydnonesbrominate in both the 4 position of the sydnone ring and on the phenyl ring. Thus, it seemed likely that Friedel-Crafts reactions on an activated sydnone would give diacylated species for McMurray coupling to sydnoquinolines. Friedel-Crafts acylations on the 4 position of the sydnone ring have been achieved in high yields using 4 equivalents of various alkyl anhydrides, 25 mol % of bismuth …

Modifications Of Human Βa1/Βa3-Crystallins Include S-Methylation, Glutathiolation, And Truncation, Veniamin N. Lapko, Ronald Cerny, David L. Smith, Jean B. Smith

Ronald Cerny Publications

Disulfide bonding of lens crystallins contributes to the aggregation and insolubilization of these proteins that leads to cataract. A high concentration of reduced glutathione is believed to be key in preventing oxidation of crystallin sulfhydryls to form disulfide bonds. This protective role is decreased in aged lenses because of lower glutathione levels, especially in the nucleus. We recently found that human [1]-crystallins undergo S-methylation at exposed cysteine residues, a reaction that may prevent disulfide bonding. We report here that βA1/A3-crystallins are also methylated at specific cysteine residues and are the most heavily methylated of the human lens crystallins. Among the …