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Iron

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Full-Text Articles in Chemistry

The Investigation Of Iron(Ii) Complexes And Their Catalytic Applications, Matthew Joseph Lenze May 2013

The Investigation Of Iron(Ii) Complexes And Their Catalytic Applications, Matthew Joseph Lenze

Dissertations

Several new η5-indenyl (Ind) complexes of iron featuring phosphinooxazoline (PHOX) ligands were synthesized and spectroscopically characterized and in a few cases structurally. The complexes were synthesized using phosphinooxazoline ligands and the corresponding iron precursor [Fe(η5-Ind) I(CO)2], yielding novel piano-stool iron complexes of the general formula [Fe(η5-Ind)(CO)(PHOX)]+ in 73% to 81% isolated yields. The complexes were tested for their efficacy in a carbon-carbon bond formation known as the Mukaiyama aldol reaction. The [Fe(η5-Ind)(CO)(PHOX)]+ complexes were capable of activating the carbonyl of aromatic aldehydes towards by attack 1-(tertbutyldimethylsilyloxy)-1-methoxyethene to form the expected silyl protected β-hydroxyesters. In these complexes, the η5-η3 haptotropic shift …

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Design And Synthesis Of Fluorescence Turn-On Probes For Iron, Randy K. Jackson Nov 2012

Design And Synthesis Of Fluorescence Turn-On Probes For Iron, Randy K. Jackson

Master's Theses

No abstract provided.

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The Fe-Type Nitrile Hydratase From Comamonas Testosteroni Ni1 Does Not Require An Activator Accessory Protein For Expression In Escherichia Coli, Misty L. Kuhn, Salette Martinez, Natalie Gumataotao, Uwe Bornscheuer, Dali Liu, Richard C. Holz Aug 2012

The Fe-Type Nitrile Hydratase From Comamonas Testosteroni Ni1 Does Not Require An Activator Accessory Protein For Expression In Escherichia Coli, Misty L. Kuhn, Salette Martinez, Natalie Gumataotao, Uwe Bornscheuer, Dali Liu, Richard C. Holz

Chemistry Faculty Research and Publications

We report herein the functional expression of an Fe-type nitrile hydratase (NHase) without the co-expression of an activator protein or the Escherichia coli chaperone proteins GroES/EL. Soluble protein was obtained when the α- and β-subunit genes of the Fe-type NHase Comamonas testosteroni Ni1 (CtNHase) were synthesized with optimized E. coli codon usage and co-expressed. As a control, the Fe-type NHase from Rhodococcus equi TG328–2 (ReNHase) was expressed with (ReNHase+Act) and without (ReNHase−Act) its activator protein, establishing that expression of a fully functional, metallated ReNHase enzyme requires the …

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Global Estimates Of Mineral Dust Aerosol Iron And Aluminum Solubility That Account For Particle Size Using Diffusion-Controlled And Surface-Area-Controlled Approximations, Qin Han, Charles S. Zender, J. Keith Moore, Clifton S. Buck, Ying Chen, Anne Johansen, Christopher I. Measures Jun 2012

Global Estimates Of Mineral Dust Aerosol Iron And Aluminum Solubility That Account For Particle Size Using Diffusion-Controlled And Surface-Area-Controlled Approximations, Qin Han, Charles S. Zender, J. Keith Moore, Clifton S. Buck, Ying Chen, Anne Johansen, Christopher I. Measures

All Faculty Scholarship for the College of the Sciences

Mineral aerosol deposition is recognized as the dominant source of iron to the open ocean and the solubility of iron in the dust aerosol is highly variable, with measurements ranging from 0.01–80%. Global models have difficulty capturing the observed variations in solubility, and have ignored the solubility dependence on aerosol size. We introduce two idealized physical models to estimate the size dependence of mineral aerosol solubility: a diffusion‐controlled model and a surface‐area‐controlled model. These models produce differing time‐ and space‐varying solubility maps for aerosol Fe and Al given the dust age at deposition, size‐resolved dust entrainment fields, and the aerosol …

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Synthesis And Structural Characterization Of Iron(Ii) Complexes With Tris(Imidazolyl)Phosphane Ligands: A Platform For Modeling The 3-Histidine Facial Triad Of Nonheme Iron Dioxygenases, Michael M. Bittner, Jacob Baus, Sergey V. Lindeman, Adam T. Fiedler Apr 2012

Synthesis And Structural Characterization Of Iron(Ii) Complexes With Tris(Imidazolyl)Phosphane Ligands: A Platform For Modeling The 3-Histidine Facial Triad Of Nonheme Iron Dioxygenases, Michael M. Bittner, Jacob Baus, Sergey V. Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

Several monoiron(II) complexes containing tris(imidazolyl)phosphane (TIP) ligands have been prepared and structurally characterized by using X-ray crystallography and NMR spectroscopy. Two TIP ligands were employed: tris(2-phenylimidazol-4-yl)phosphane (4-TIPPh) and tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphane (2-TIPPh2). These tridentate ligands resemble the 3-histidine (3His) facial triad found recently in the active sites of certain nonheme iron dioxygenases. Three of the reported complexes are designed to serve as convenient precursors to species that model the enzyme–substrate intermediates of 3His dioxygenases; thus, each contains an [Fe(κ3-TIP)]2+ unit in which the remaining coordination sites are occupied by easily displaced ligands, such as solvent …

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Ag Nanoparticles Self-Assembled Films On Iron Surface And Their Inhibition Properties, Zhe Zhang, Ming-Zi Jia, Le Ruan Feb 2012

Ag Nanoparticles Self-Assembled Films On Iron Surface And Their Inhibition Properties, Zhe Zhang, Ming-Zi Jia, Le Ruan

Journal of Electrochemistry

The Ag nanoparticles were prepared in aqueous solutions through a chemical reduction method and transferred from water phase to toluene phase with the protection of 1-dodecanethiol (DDT). The polished iron electrode was immersed in the DDT-protected metal nanoparticles toluene solutions to form DDT/Ag nanoparticles self-assembled mixed films. Electrochemical methods such as electrochemical impedance spectroscopy and polarization curve measurement were used to study the inhibition properties of the self-assembled films in the 0.5 mol·L-1 H2SO4 solution. The appearance of elements such as S and Ag from the XPS data identified the presences of DDT and Ag nanoparticles.

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Optimization Of A New Cloud Point Extraction Procedure For The Selective Determination Of Trace Amounts Of Total Iron In Some Environmental Samples, Celal Duran, Duygu Özdeş, Eli̇f Çelenk Kaya, Hali̇t Kanteki̇n, Volkan Numan Bulut, Mehmet Tüfekçi̇ Jan 2012

Optimization Of A New Cloud Point Extraction Procedure For The Selective Determination Of Trace Amounts Of Total Iron In Some Environmental Samples, Celal Duran, Duygu Özdeş, Eli̇f Çelenk Kaya, Hali̇t Kanteki̇n, Volkan Numan Bulut, Mehmet Tüfekçi̇

Turkish Journal of Chemistry

A new, simple, and rapid cloud point extraction (CPE) procedure system, combined with flame atomic absorption spectrometry (FAAS), was developed for selective separation, preconcentration, and determination of trace amounts of total iron in some environmental samples. The complexing agent, N,N'-(2,2'-(ethane-1,2-diylbis(oxy)) bis(ethane-2,1-diyl))bis(2-chloroacetamide) (EDBOCA), is selective at pH 5.0 for only Fe(II) and Fe(III) ions in the presence of Cu(II), Pb(II), Cd(II), Mn(II), Co(II), Cr(III), Cr(VI), Ni(II), Zn(II), Al(III), Mo(VI), Pd(II), Pt(IV), Au(III), and V(V) ions. The procedure is based on the complexation of Fe(III) ions with EDBOCA reagent in the presence of Triton X-114 (TX-114) as a non-ionic surfactant. The optimum …

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Neutron Repulsion, Oliver Manuel Jan 2012

Neutron Repulsion, Oliver Manuel

Chemistry Faculty Research & Creative Works

Earth is connected gravitationally, magnetically and electrically to its heat source and the source of its chemical elements - a neutron star obscured from view by waste products in the photosphere. Neutron repulsion makes the solar core like the hot filament in an incandescent light bulb. Excited neutrons are emitted from the pulsar, decay to hydrogen, and partially fuse into the helium now trapped with it in the photosphere, like a frosted light bulb. Neutron repulsion is the overlooked source of energy, the keystone of an arch that locks together many earlier, puzzling observations: 1.) Excess 136Xe accompanied primordial …

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Prevention Of Iron- And Copper-Mediated Oxidative Dna Damage By Neurotransmmitters And Related Compounds: Evidence For Metal Binding As An Antioxidant Mechanism, Carla Garcia Dec 2011

Prevention Of Iron- And Copper-Mediated Oxidative Dna Damage By Neurotransmmitters And Related Compounds: Evidence For Metal Binding As An Antioxidant Mechanism, Carla Garcia

All Theses

An array of health concerns have been attributed to oxidative DNA damage from the hydroxyl radical (*OH), and the presence of the most biologically available metals iron and copper perpetuate the production of this radical through the Fenton and Fenton-like reactions, respectively. The concentrations at which flavonol and polyphenol antioxidants prevent 50% of DNA damage (IC50) were measured using gel electrophoresis assays upon Fe(II)/H2O2- and Cu(I)/H2O2-mediated DNA damage (Chapter 2). Results show that catechol- and gallol-containing antioxidants differ greatly in preventing DNA damage by Cu(I)/H2O2, compared to Fe(II)/H2O2, behavior that was explained using electron paramagnetic resonance spectroscopy. Semiquinone and other …

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Slow Magnetic Relaxation And Electron Delocalization In An S = 9/2 Iron(Ii/Iii) Complex With Two Crystallographically Inequivalent Iron Sites, Susanta Hazra, Sujit Sasmal, Michel Fleck, Fernande Grandjean, Moulay T. Sougrati, Meenakshi Ghosh, T. David Harris, Pierre Bonville, Gary J. Long, Sasankasekhar Mohanta May 2011

Slow Magnetic Relaxation And Electron Delocalization In An S = 9/2 Iron(Ii/Iii) Complex With Two Crystallographically Inequivalent Iron Sites, Susanta Hazra, Sujit Sasmal, Michel Fleck, Fernande Grandjean, Moulay T. Sougrati, Meenakshi Ghosh, T. David Harris, Pierre Bonville, Gary J. Long, Sasankasekhar Mohanta

Chemistry Faculty Research & Creative Works

The magnetic, electronic, and Mössbauer spectral properties of Fe 2L(µ-OAc)2ClO4, 1, where L is the dianion of the tetraimino-diphenolate macrocyclic ligand, H2L, indicate that 1 is a class III mixed valence iron(II/III) complex with an electron that is fully delocalized between two crystallographically inequivalent iron sites to yield a [Fe2]V cationic configuration with a St 9/2 ground state. Fits of the dc magnetic susceptibility between 2 and 300K and of the isofield variable-temperature magnetization of 1 yield an isotropic magnetic exchange parameter, J, of -32(2) cm-1 for an …

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Design, Synthesis, And Characterization Of A Tetraamide Macrocyclic Ligand And Its Fe- Complex For Green Oxidation Chemistry, Shane Z. Sullivan Sep 2010

Design, Synthesis, And Characterization Of A Tetraamide Macrocyclic Ligand And Its Fe- Complex For Green Oxidation Chemistry, Shane Z. Sullivan

Theses and Dissertations

This work presents the spectroscopic characterization and catalytic investigation of a FeIII-complex of a tetraamidomacrocyclic ligand. Under catalytic conditions the complex is soluble in aqueous solutions and rapidly activates hydrogen peroxide under mild reaction conditions. Both the kinetics and extent of water-soluble dye and paper effluent H2O2-bleaching catalyzed was found to be comparable to known FeIII-TAML complexes. As an additional application, the complex showed potential for the synthesis of a variety of Noxides from their corresponding amines as demonstrated by its high turnover number and essentially stoichiometric yield in selected amines. Electrospray ionization-mass spectrometry of the complex reveals a peak …

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Hydrogen Storage And Carbon Dioxide Capture In An Iron-Based Sodalite-Type Metal-Organic Framework (Fe-Btt) Discovered Via High-Throughput Methods, Kenji Sumida, Satoshi Horike, Steven S. Kaye, Zoey R. Herm, Wendy L. Queen, Craig M. Brown, Fernande Grandjean, Gary J. Long, Anne M. Dailly, Jeffrey R. Long Aug 2010

Hydrogen Storage And Carbon Dioxide Capture In An Iron-Based Sodalite-Type Metal-Organic Framework (Fe-Btt) Discovered Via High-Throughput Methods, Kenji Sumida, Satoshi Horike, Steven S. Kaye, Zoey R. Herm, Wendy L. Queen, Craig M. Brown, Fernande Grandjean, Gary J. Long, Anne M. Dailly, Jeffrey R. Long

Chemistry Faculty Research & Creative Works

Using high-throughput instrumentation to screen conditions, the reaction between FeCl2 and H3BTT·2HCl (BTT3- = 1,3,5-benzenetristetrazolate) in a mixture of DMF and DMSO was found to afford Fe3[(Fe4Cl)3(BTT)8] 2·22DMF·32DMSO·11H2O. This compound adopts a porous three-dimensional framework structure consisting of square [Fe4Cl]7+ units linked via triangular BTT3- bridging ligands to give an anionic 3,8-net. Mössbauer spectroscopy carried out on a DMF-solvated version of the material indicated the framework to contain high-spin Fe2+ with a distribution of local environments and confirmed the presence …

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New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer Apr 2010

New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer

Educator Preparation & Leadership Faculty Works

New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)2PNR’2 (R = binaphthyl, R’ = CH3, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)2] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)2] in the presence of catalytic [Fe(Cp)(CO)2]2 afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the …

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The Heat Capacity And Thermodynamic Properties Of The Iron Oxides And Their Relation To The Mineral Core Of The Iron Storage Protein Ferritin, Claine Lindsey Morton Snow Feb 2010

The Heat Capacity And Thermodynamic Properties Of The Iron Oxides And Their Relation To The Mineral Core Of The Iron Storage Protein Ferritin, Claine Lindsey Morton Snow

Theses and Dissertations

The iron oxides are a group of materials with geological, biological, and technological importance. A thermodynamic understanding of these materials is important because it provides information about their relative stabilities, chemical reactivity, and transformations. This study provides the heat capacity of a nanocrystalline magnetite (Fe3O4) sample, bulk hematite (α-Fe2O3), nanocrystalline hematite, akaganéite (β-FeOOH), and lepidocrocite (γ-FeOOH) at temperatures as low as 0.5 K. These measurements were fit to theoretical functions at temperatures lower than 15 K, and the respective thermophysical properties of these materials are discussed. Also the molar entropies of bulk hematite and hydrous nanocrystalline hematite as well as …

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Recent Applications Of Acyclic (Diene)Iron Complexes And (Dienyl)Iron Cations In Organic Synthesis, William A. Donaldson, Subhabrata Chaudhury Aug 2009

Recent Applications Of Acyclic (Diene)Iron Complexes And (Dienyl)Iron Cations In Organic Synthesis, William A. Donaldson, Subhabrata Chaudhury

Chemistry Faculty Research and Publications

Complexation of (tricarbonyl)iron to an acyclic diene serves to protect the ligand against oxidation, reduction, and cycloaddition reactions, whereas the steric bulk of this adjunct serves to direct the approaches of reagents to unsaturated groups attached to the diene onto the face opposite to iron. Furthermore, the Fe(CO)3 moiety can serve to stabilize carbocation centers adjacent to the diene (i.e. pentadienyl-iron cations). Recent applications of these reactivities to the synthesis of polyene-, cyclopropane-, cycloheptadiene-, and cyclohexenone-containing natural products or analogues are presented.

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Hydroxyl Radical Is Produced Via The Fenton Reaction In Submitochondrial Particles Under Oxidative Stress: Implications For Diseases Associated With Iron Accumulation, Carin Thomas, Melissa M. Mackey, Amy A. Diaz, David P. Cox Jan 2009

Hydroxyl Radical Is Produced Via The Fenton Reaction In Submitochondrial Particles Under Oxidative Stress: Implications For Diseases Associated With Iron Accumulation, Carin Thomas, Melissa M. Mackey, Amy A. Diaz, David P. Cox

All Faculty Scholarship for the College of the Sciences

Mitochondrial dysfunction and reactive oxygen species (ROS) are often implicated in diseases involving oxidative stress and elevated iron. As mitochondria produce ATP by oxidative phosphorylation, ROS by-products are generated from the electron transport chain. Although superoxide and hydrogen peroxide have been thoroughly investigated, little evidence documents hydroxyl radical (HO•) production in mitochondria. In order to determine whether HO• is generated under oxidative stress conditions by a Fenton-type mechanism, bovine heart submitochondrial particles were examined for HO• in the presence and absence of iron ligands, antioxidant enzymes and HO• scavengers. HO• was measured as 2,3- and 2,5-dihydroxybenzoic acid (DHBA), using HPLC …

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Corrosion Inhibition Of Self-Assembled Films On Iron By Electrochemical Impedance Spectroscopy, Yuan-Yuan Feng, Shen-Hao Chen, Juan-Juan Zhou, Wen-Juan Guo Aug 2008

Corrosion Inhibition Of Self-Assembled Films On Iron By Electrochemical Impedance Spectroscopy, Yuan-Yuan Feng, Shen-Hao Chen, Juan-Juan Zhou, Wen-Juan Guo

Journal of Electrochemistry

The self-assembled films of tetradecylamine were formed on iron surface, and the inhibition ability of which for iron corrosion in 0.5 mol/L H2SO4 solutions was studied by electrochemical impedance spectroscopy technique. Results indicated that longer immersion time would result in stronger inhibition ability of the films. The maximal inhibition efficiency(IE) of the tetradecylamine films was 68.7%. When the tetradecylamine films were modified by dodecylthiol, the mixed films became denser and more stable, thus the inhibition ability increased remarkably. The η of the mixed films increased to 78.2%.

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Magnetic Nanoparticles Based On Iron: Synthesis, Characterization, Design, And Application, Michael David Shultz Jan 2008

Magnetic Nanoparticles Based On Iron: Synthesis, Characterization, Design, And Application, Michael David Shultz

Theses and Dissertations

Magnetic nanoparticles are of great interest for a wide range of applications. This work has focused on three primary forms of iron based nanoparticles and combinations thereof: α-iron, iron oxide, and iron carbide or cementite. The synthesis of several core-shell particles including cementite-iron oxide, α-iron-cementite, and α-iron-iron oxide was accomplished through reverse micelle routes and high temperature decomposition of iron pentacarbonyl in various media. Structural analysis to confirm the structures was performed using extended x-ray absorption fine structure (EXAFS) techniques. A rapid characterization technique was developed utilizing a correlation between Fourier transform infrared spectroscopy and EXAFS to determine the full …

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A Mössbauer Spectral Study Of The Gdco₄₋ₓfeₓb Compounds, Fernande Grandjean, Raphäel P. Hermann, Eustachy S. Popiel, Gary J. Long Jan 2007

A Mössbauer Spectral Study Of The Gdco₄₋ₓfeₓb Compounds, Fernande Grandjean, Raphäel P. Hermann, Eustachy S. Popiel, Gary J. Long

Chemistry Faculty Research & Creative Works

The iron-57 Mössbauer spectra of the GdCo4-xFexB compounds, where x is 0.10, 0.15, 0.20, 0.25, 1, 2, 2.5, and 2.6, have been measured at room temperature and reveal relatively small iron hyperfine fields of approximately 12-18 T, relatively large quadrupole interactions of approximately +0.9 and -1 mm/s, and three very different types of spectra for x=0.10 and 0.15, x=0.25, 1, and 2, and x=2.5 and 2.6. The differences result from both the different easy magnetization directions in these compounds and the different cobalt and/or iron occupancies of the crystallographic 2c and 6i sites. The spectra have …

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Oxidative Damage Caused By Iron Loading Into Ferritin, Talina Christensen Watts May 2006

Oxidative Damage Caused By Iron Loading Into Ferritin, Talina Christensen Watts

Undergraduate Honors Capstone Projects

Ferritin is the iron storage protein found in humans, animals, plants, fungi and bacteria. We are interested in how iron is loaded and stored in mammalian ferritin. Ferrous iron must be oxidized to ferric iron in order to be stored in ferritin. It is generally believed that ferritin does the loading itself, dependant upon a "ferroxidase activity." Oxidation of iron can result in the production of the hydroxyl radical which can cause oxidative damage to surrounding proteins and other biomolecules. An indicator of oxidative damage to proteins is the formation of carbonyl groups. Using only the H subunit of human …

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Large Scale Growth And Magnetic Properties Of Fe And Fe₃O₄ Nanowires, Jinbo Yang, H. Xu, Shaoxin You, X.-D. Zhou, C. S. Wang, William B. Yelon, William Joseph James Apr 2006

Large Scale Growth And Magnetic Properties Of Fe And Fe₃O₄ Nanowires, Jinbo Yang, H. Xu, Shaoxin You, X.-D. Zhou, C. S. Wang, William B. Yelon, William Joseph James

Materials Science and Engineering Faculty Research & Creative Works

Fe and Fe3O4 nanowires have been synthesized by thermal decomposition of Fe(CO)5, followed by heat treatments. The Fe wires are formed through the aggregation of nanoparticles generated by decomposition of Fe(CO)5. A core-shell structure with an iron oxide shell and Fe core is observed for the as-prepared Fe wires. Annealing in air leads to the formation of Fe2O3/Fe3O4 wires, which after heat treatment in a N2/alcohol atmosphere form Fe3O4 wires with a sharp Verwey [Nature (London) 144, 327 (1939)] transition at 125 K. The Fe3O4 wires have coercivities of 261 and 735 Oe along the wire axis at RT and …

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Template Synthesis And Structural Characterization Of Homo Binuclear Chromium(Iii), Manganese(Iii), Iron(Iii), Cobalt(Iii), And Ruthenium(Iii) Complexes With Octaazamacrocyclic Ligands, Vinod K. Sharma, Shipra Srivastava Jan 2006

Template Synthesis And Structural Characterization Of Homo Binuclear Chromium(Iii), Manganese(Iii), Iron(Iii), Cobalt(Iii), And Ruthenium(Iii) Complexes With Octaazamacrocyclic Ligands, Vinod K. Sharma, Shipra Srivastava

Turkish Journal of Chemistry

The Schiff base octaazamacrocyclic ligands derived from primary diamines and 3,6-dimethyl/diphenyl-4,5-diazaocta-3,5-diene-2,7-dione, and their binuclear complexes [M_2LCl_4]Cl_2 [M = Cr(III), Fe(III), Co(III), or Ru(III)] and [Mn_2L(AcO)_4](AcO)_2 were synthesized by template condensation reactions. Attempts to synthesize the corresponding metal-free macrocyclic ligands did not prove successful. The overall geometry and stereochemistry of these complexes were elucidated by elemental analyses, magnetic susceptibilities, electronic spectra, infrared spectra, molar conductance measurements, ^1H NMR, and thermogravimetric analysis. All the trivalent metal ion complexes appear to be 1:2 electrolytes. An octahedral geometry is proposed for all the complexes.

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Exploration Of Iron And Cobalt Core-Shell Nanoparticles Via Thermal And Microwave Polyol Synthesis, Hope M. Klukovich Jan 2006

Exploration Of Iron And Cobalt Core-Shell Nanoparticles Via Thermal And Microwave Polyol Synthesis, Hope M. Klukovich

Browse all Theses and Dissertations

Thermal and microwave polyol methods were investigated in the synthesis of various iron and cobalt core-shell nanoparticles. The reaction involved 1 mmol of an Fe+2 or Co+2 salt, bis-acetylacetanato [(Acac)2] iron (II), cobalt (Acac)2 or iron (II) acetate along with 1 mmol of a surfactant capping agent. The salt was reduced with 2 mmol of a 1,2 diol. When 1,2-hexadecanediol solid was used as a reducing agent, it was dissolved along with the metal salt and capping agent in octyl ether. When 1,2-hexanediol liquid was used as the reducing agent, it was also the solvent, and octyl ether …

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Strongly Decoupled Europium And Iron Vibrational Modes In Filled Skutterudites, Gary J. Long, Raphäel P. Hermann, Fernande Grandjean, Ercan E. Alp, Wolfgang Sturhahn, Charles E. Johnson, Dennis E. Brown, Olaf Leupold, Rudolf Rüffer Apr 2005

Strongly Decoupled Europium And Iron Vibrational Modes In Filled Skutterudites, Gary J. Long, Raphäel P. Hermann, Fernande Grandjean, Ercan E. Alp, Wolfgang Sturhahn, Charles E. Johnson, Dennis E. Brown, Olaf Leupold, Rudolf Rüffer

Chemistry Faculty Research & Creative Works

The europium partial vibrational density of states (DOS) in EuFe4Sb12 and the iron partial vibrational DOS in both EuFe4Sb12 and Ce57Fe4Sb12 have been obtained by nuclear inelastic scattering. The results reveal the strong independence of the iron and rare-earth vibrational modes. The cage filling europium only participates significantly to the low-energy local vibrational modes. The force constants have been obtained from the measured probability of nuclear absorption. The energies of the peaks in the europium and iron DOS are in excellent agreement with the calculated DOS in LaFe4 …

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Determination Of Cadmium, Copper, Iron, Manganese, Lead And Zinc In Lichens And Botanic Samples By Electrothermal And Flame Atomic Absorption Spectrometry, Orhan Acar, Sümer Özvatan, Murat İli̇m Jan 2005

Determination Of Cadmium, Copper, Iron, Manganese, Lead And Zinc In Lichens And Botanic Samples By Electrothermal And Flame Atomic Absorption Spectrometry, Orhan Acar, Sümer Özvatan, Murat İli̇m

Turkish Journal of Chemistry

Within the framework of the International Atomic Energy Agency (IAEA) Analytical Quality Control Service (AQCS) Chemistry Unit a research program was initiated for the identification of trace elements such as Cd, Cu, Fe, Mn, Pb and Zn in IAEA lichen-338 for a proficiency test (PT). This was to evaluate the possibility of using lichens as biomonitors of trace elements in atmospheric pollution. Pyrolysis and atomization temperatures, atomization and background profiles, detection limits and characteristic masses of analytes in lichen samples with Ni, Ni + Pd and Ni + Pd + tartaric acid (TA) modifier mixture, and without any modifiers were …

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Reaction Rates For The Dehalogenation Of Trichloroethylene Using Various Types Of Zero-Valent Iron, Neil Stewart Jan 2005

Reaction Rates For The Dehalogenation Of Trichloroethylene Using Various Types Of Zero-Valent Iron, Neil Stewart

Electronic Theses and Dissertations

Remediation of trichloroethylene (TCE) and other chlorinated solvents is of great concern due to their toxicity and their persistence in the environment. Iron has been used extensively in the past decade as a subsurface reactive agent for the remediation of dense, nonaqueous-phase liquids (DNAPLs). Permeable reactive barrier walls (PRBW) have been installed at many sites around the country to treat contaminated plumes resulting from the presence of DNAPL pools. The use of zero-valent metals, such as iron, to effectively reductively dechlorinate DNAPLs has been employed as the reactive material in these PRBWs (Gillham et al., 1993). However, limited work has …

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Synthesis Of Isomorphous Prototypic [Crfe_2o(Aco)_6(Tep)_3]Cl And [Crfe_2o(Aco)_6(Tmp)_3]Cl As Oxo-Centered Hetero Tri-Nuclear Carboxylate Complexes, Massoud Rafizadeh, Reza Tayebee, Vahid Amani Jan 2005

Synthesis Of Isomorphous Prototypic [Crfe_2o(Aco)_6(Tep)_3]Cl And [Crfe_2o(Aco)_6(Tmp)_3]Cl As Oxo-Centered Hetero Tri-Nuclear Carboxylate Complexes, Massoud Rafizadeh, Reza Tayebee, Vahid Amani

Turkish Journal of Chemistry

[CrFe_2O(AcO)_6(TEP)_3]Cl, (1), and [CrFe_2O(AcO)_6(TMP)_3]Cl, (2), were prepared by replacing 3 water molecules in the [CrFe_2O(AcO)_6(H_2O)_3]Cl complex with triethyl- and trimethyl-phosphates, respectively. FT-IR spectroscopy confirmed an oxo-centered, carboxylate-bridged, heteronuclear triangular structure for the title compounds. M_3O and MO_4 units adopted D_{3h} and D_{4h} local symmetry, respectively, and are surrounded by 6 bridging acetates with C_{2v} local symmetry.

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Mössbauer Spectral Study Of The Magnetocaloric Femnp₁₋ₓasₓ Compounds, Raphäel P. Hermann, Ojied Tegus, Ekkehard H. Brück, K. H. J. Buschow, Frank R. De Boer, Gary J. Long, Fernande Grandjean Dec 2004

Mössbauer Spectral Study Of The Magnetocaloric Femnp₁₋ₓasₓ Compounds, Raphäel P. Hermann, Ojied Tegus, Ekkehard H. Brück, K. H. J. Buschow, Frank R. De Boer, Gary J. Long, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The magnetic phase transitions in the FeMnP1-xAsx compounds with x= 0.25, 0.35, 0.45, 0.50, and 0.55, have been studied by iron-57 Mössbauer spectroscopy. The ferromagnetic and antiferromagnetic spectra have been analyzed with a model that takes into account the random distribution of the P and As near-neighbor anions of a given iron site. This distribution is a binomial distribution of the contributions to the spectra of each iron with n As near neighbors. A magnetostriction model has been used to characterize the temperature induced paramagnetic to ferromagnetic first-order phase transition and order parameters, ηF=2.6, 2.3, …

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The Effect Of Ferrous Sulphate On The Electroless Depositionof Co-Fe-P Alloys, Sen-Lin Wang, Qing-Hua Li Aug 2004

The Effect Of Ferrous Sulphate On The Electroless Depositionof Co-Fe-P Alloys, Sen-Lin Wang, Qing-Hua Li

Journal of Electrochemistry

Electroless deposition of Co-P alloy and Co-Fe-P alloy from an alkaline bath, containing sodium hypophosphite as a reducer, boric acid as a buffer agent and sodium citrate as a complexing agent, was investigated respectively. The effects of process parameters, such as pH of solution and metallic salt mole ratio of CoSO4/FeSO4, on the plating rate were examined. It was found that the presence of ferrous sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the plating rate of Co-Fe-P is lower than that of Co-P. The electrochemical polarization measurements have …

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Characterization And Magnetic Properties Of Core/Shell Structured Fe/Au Nanoparticles, Sung-Jin Cho, Susan M. Kauzlarich, Justin Olamit, Kai Liu, Fernande Grandjean, Leïla Rebbouh, Gary J. Long Jun 2004

Characterization And Magnetic Properties Of Core/Shell Structured Fe/Au Nanoparticles, Sung-Jin Cho, Susan M. Kauzlarich, Justin Olamit, Kai Liu, Fernande Grandjean, Leïla Rebbouh, Gary J. Long

Chemistry Faculty Research & Creative Works

Au-coated Fe nanoparticles have been prepared by using a reverse micelle method through reduction of an aqueous solution. Characterizations have been carried out over time to probe the oxidation of Fe. Immediately after synthesis, the samples exhibit metallic conduction and a negative magnetoresistance, consistent with the presence of α-Fe. The temperature dependence of magnetization displays a maximum at a blocking temperature of around 150 K. After a period of 1 month, the samples exhibit insulating behavior, indicating the oxidation of the Fe core. Mössbauer spectroscopy indicates the presence of an α-Fe component and a broad distribution of local environments.

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