1345-25-1Relevant articles and documents
Reduction of FeO/Pt(1 1 1) thin films by exposure to atomic hydrogen
Knudsen, Jan,Merte, Lindsay R.,Grabow, Lars C.,Eichhorn, Falk M.,Porsgaard, Soeren,Zeuthen, Helene,Vang, Ronnie T.,L?gsgaard, Erik,Mavrikakis, Manos,Besenbacher, Flemming
, p. 11 - 20 (2010)
Using scanning tunneling microscopy (STM), X-ray photoemission spectroscopy (XPS) and density functional theory (DFT) calculations we have studied the reduction of ultra-thin films of FeO(1 1 1) grown on Pt(1 1 1) after exposure to atomic hydrogen at room temperature. A number of new ordered, partly-reduced FeOx structures are identified and as a general trend we reveal that all the reduced FeOx structures incorporate 2-fold coordinated Fe atoms as opposed to the original 3-fold coordinated Fe atoms in the FeO film. We find that when all the Fe atoms are 2-fold O-coordinated the FeOx surface structure is resistant to further reduction at room temperature. We observe that water easily dissociates on the most heavily reduced FeOx, structure in contrast to the initially inert FeO film, and reveal that it is possible to partially re-oxidize the FeOx film by heating the surface slightly in the presence of water.
Ajersch, F.,Benlyamani, M.
, p. 221 - 238 (1989)
REACTION PROCESS BETWEEN alpha -IRON(III) OXIDE AND SULFUR DIOXIDE IN THE PRESENCE OF CARBON.
Araki,Ryoo,Eguchi,Matsuzaki,Saeki
, p. 2271 - 2274 (1980)
The reaction products obtained by heating a mixture of alpha -Fe//2O//3 and carbon in a SO//2 stream at various temperatures were examined. The possible reactions during the above process were also examined The solid products obtained by heating a mixture of alpha -Fe//2O//3 and carbon in a SO//2 stream were Fe//3O//4 at 500 - 700 degree C, pyrrhotite and Fe//3O//4 at 750 degree C, and pyrrhotite (Fe//0//. //8//8S) alone at 800 degree C. Sulfur was obtained outside the heating zone throughout the temperature range. The reaction between carbon and SO//2 occurs even at 350 degree C to form sulfur, and the reaction proceeds markedly above ca. 700 degree C. Above ca. 500 degree C, the reductions of alpha -Fe//2O//3 with carbon and sulfur occur to form Fe//3O//4. Above ca. 750 degree C, pyrrhotite is formed by the reaction between Fe//3O//4 and sulfur. These results were supported by the thermodynamical consideration based on the chemical potential diagram for the Fe-S-C-O system.
Monolayer iron oxide film on platinum promotes low temperature CO oxidation
Sun,Qin,Lewandowski,Carrasco,Sterrer,Shaikhutdinov,Freund
, p. 359 - 368 (2009)
CO oxidation on a clean Pt(1 1 1) single crystal and thin iron oxide films grown on Pt(1 1 1) was studied at different CO:O2 ratios (between 1:5 and 5:1) and partial pressures up to 60 mbar at 400-450 K. Structural characterization of the model
M?ssbauer and X-ray diffraction investigation of nanocrystalline Fe-O alloys
Lileev,Yagodkin,Reissner,Steiner
, p. 504 - 506 (2003)
X-ray and M?ssbauer investigations were carried out on powders produced by milling of Fe2O3 + α-Fe mixtures in a high-energy ball mill and subsequent low-temperature annealing. The nanocrystalline composite alloys obtained as a result of the milling, contained FeO and α-Fe with an average crystallite size of 15-20nm as well as an amorphous phase. Alloys subjected to subsequent annealing contained, however, only α-Fe + Fe3O4 with an average crystallite size of about 20nm. Unlike the starting materials the produced powders had properties, which are characteristic for hard magnetic materials.
One-dimensional pyrazine bridged M(II)-saccharinato coordination polymers: Synthesis, characterization, crystal structures and thermal studies
Yilmaz, Veysel T.,Senel, Evrim,Kazak, Canan
, p. 3199 - 3204 (2007)
Three new coordination polymers with a general formula [M(sac)2(μ-pyz)(H2O)2]n [M = Mn(II) (1), Fe(II) (2), Co(II) (3), pyz = pyrazine, and sac = saccharinate] have been synthesized and characterized by elemental analyses, IR, UV-VIS, magnetic measurements, thermal analysis techniques and single crystal X-ray diffraction. All three complexes are isomorphous, crystallizing in the triclinic space group P over(1, ?) (No. 2). Each metal(II) ion in 1-3 is octahedrally coordinated by two sac, two pyz and two aqua ligands. The sac ligands are N-coordinated, while the pyz ligands bridge the metal centers leading to an one-dimensional linear chain structure. Intra-chain M-M separations in complexes 1, 2 and 3 are 7.381(2), 7.259(3) and 7.188(3) A?, respectively. The individual chains are linked into two-dimensional layers by O-H?O hydrogen bonds involving the hydrogens of aqua ligands and carbonyl and sulfonyl O atoms of sac ligands. The hydrogen bonded layers are further assembled into three-dimensional supramolecular networks by weak aromatic π?π stacking interactions between the phenyl rings of sac ligands or CH?π interactions involving pyz. These complexes exhibit similar decomposition characteristics. In the first stages, endothermic removal of the aqua and pyz ligand takes place leading to an intermediate probably in the form of [M(sac)2], which undergoes highly exothermic decomposition at higher temperatures to give corresponding metal oxides.
Alidjanov, E. K.,Atabaev, B. G.,Prokhozev, K. Yu.,Rasulev, U. Kh.
, p. 363 - 368 (1994)
COMPARATIVE THERMOGRAVIMETRIC STUDY OF CHLORINATIONS OF HEMATITE AND WUSTITE.
Bertoti,Pap,Szekely,Babievskaya
, p. 281 - 292 (1987)
The reactions of hematite and wustite with Cl//2, COCl//2, CO plus Cl//2 and gaseous CCl//4 were studied by thermogravimetry, X-ray diffraction and computer-assisted thermodynamic calculations. During the chlorination of hematite, only gaseous products were formed. The apparent activation energies were calculated from the isothermal TG curves. The chlorination of wustite involves the formation and transformation of a series of solid chloride products. FeCl//2(s), FeCl//3(s) and FeOCl(s) were found as intermediates during chlorination with Cl//2 or Cl//2 plus CO, while only FeCl//2(s) was detected in reactions with COCl//2 oe CCl//4. The chlorinations of the iron oxides with various agents were compared, and the differences in reactivity sequences were established.
Adsorption and low-temperature oxidation of CO over iron oxides
?mit, Goran,Zrn?evi?, Stanka,Lázár, Károly
, p. 103 - 106 (2006)
Different iron oxides, usually used as gold supports, were tested as catalysts for CO oxidation at low temperature. Calcinations of synthesized magnetite at different temperatures, before the activity test, caused its chemical transformations but differences in the activity were not noticeable in all the cases. A sample calcined at 873 K was significantly less active than samples calcined at 473 and 673 K. FTIR measurements in a vacuum showed that the differences in the activity were not caused by the chemical composition but by amount of surface -OH groups.
Synthesis of γ-Fe2O3 by thermal decomposition of ferrous gluconate dihydrate
Rahman,Venkataraman
, p. 91 - 101 (2002)
Ferrous gluconate dihydrate (FeC12H22O14·2H2O), was prepared and its thermal decomposition was studied by means of simultaneous thermal analysis, supplemented with a two probe d.c. electrical conductivity measurements under the atmospheres of static air, dynamic air and dynamic nitrogen. Under all the atmospheres final product was found to be α-Fe2O3 with FeO, γ-Fe2O3, Fe3O4 etc. as probable intermediates. γ-Fe2O3 was formed under the atmosphere of dynamic air containing water vapour. γ-Fe2O3 thus synthesised was characterised for its structure, morphology, thermal and magnetic behaviour.
Iron(III), copper(II), cadmium(II), and mercury(II) complexes of isatin carbohydrazone Schiff base ligand (H3L): Synthesis, characterization, X-ray diffraction, cyclic voltammetry, fluorescence, density functional theory, biological activity, and molecular docking studies
Younis, Adel M.,El-Gamil, Mohammed M.,Rakha, Tawfik H.,Abu El-Reash, Gaber M.
, (2021)
A series of some transition metal, Fe(III), Cu(II), Cd(II), and Hg(II), complexes with N′,2-bis((Z)-2-oxoindolin-3-ylidene)hydrazine-1 carbohydrazide (H3L) ligand have been synthesized, and their structures were elucidated based on their spectral analyses (Fourier transform infrared [FT-IR], 1H nuclear magnetic resonance (NMR) and 13C NMR, UV-visible (UV-Vis), electron spin resonance (ESR), powder X-ray diffraction [XRD], and mass spectroscopy), elemental analyses, conductance, and magnetic susceptibility measurements. The structures of the H3L ligand and its metal complexes were optimized using the DMol3 tool in the material studio package. The ligand behaves as binegative N2O3 pentadentate in [Fe(HL)(Cl)]·2H2O complex, mononegative N2O3 pentadentate in [Cu(H2L)(OAc)]·2H2O complex, mononegative N2O tridentate in [Cd(H2L)2]·H2O complex, and finally, neutral N2 bidentate in [Hg(H3L)(Cl)2]·2H2O complex. Coats–Redfern and Horowitz–Metzger methods were used to estimate the various thermodynamic and kinetic parameters. Cyclic voltammetry of the ligand in the absence and presence of Cd(II) and Hg(II) ions was studied. Fluorescence studies were performed in DMSO and showed that Cu(II) ions quench the fluorescence spectrum of the free ligand, whereas Cd(II) ions enhance it. The in vitro antimicrobial activities of the free ligand and its complexes against different bacterial strains and fungi Candida albicans were screened using agar-disc diffusion techniques. The antioxidant potentials of the isolated compounds were also screened by employing SOD and ABTS free radical scavenging methods. Molecular docking studies were performed using Auto-Dock tools to predict the best binding mode and predominant binding interactions.
Kinetic study of the reaction of Fe(a 5DJ) with N2O from 398 to 620 K
Campbell, Mark L.,Metzger, Joel R.
, p. 158 - 164 (1996)
The gas phase reactivity of Fe(a 5DJ) with N2O in the temperature range 398-620 K is reported. Iron atoms were produced by the photodissociation of ferrocene and detected by laser-induced fluorescence. The reaction rates of the a 5DJ states are very slow and temperature dependent. The bimolecular rate constant is described in Arrhenius form by (1.41 ± 0.29) × 10-10 exp(-44.4 ± 1.0 kJ/mol/RT) cm3 s-1 where the uncertainties are ±2σ. The disappearance rates in the presence of N2O are independent of buffer gas identity (Ar or N2) and total pressure. The removal rate constants for the a 5DJ states are independent of J.
Lopez-Delgado, A.,Garcia-Martinez, O.,Galvez-Morros, M.
, p. 843 - 852 (1988)
Construction of diverse dimensionality in eight coordination polymers of bivalent metal ions using 5-nitroisophthalate and different linear N,N′-donor linkers
Maity, Dilip Kumar,Bhattacharya, Biswajit,Halder, Arijit,Das, Anamika,Ghoshal, Debajyoti
, p. 634 - 642 (2015)
Assembly of 5-nitroisophthalate (nip2-) with first row transition metal salts [Mn(II), Fe(II), Co(II), Zn(II)] in combination with the various neutral auxiliary N,N′-donor linkers, e.g., 2,5-bis-(4-pyridyl)-3,4-diaza-2,4-hexadiene (4-bpdh), 1,3
Correlating STM contrast and atomic-scale structure by chemical modification: Vacancy dislocation loops on FeO/Pt(1 1 1)
Merte,Knudsen,Grabow,Vang,L?gsgaard,Mavrikakis,Besenbacher
, p. L15-L18 (2009)
By chemically modifying the FeO(1 1 1) thin film on Pt(1 1 1), we show that it is possible to unambiguously correlate its STM morphology with its underlying structure without recourse to STM simulations. Partial reduction of the oxide surface leads to the
Oxidation of a ternary Cu-Ni-Fe alloy under low oxygen pressures at 800-900°C
Li,Niu,Gesmundo
, p. 578 - 582 (2001)
The oxidation of a Cu-based ternary alloy containing 30 at% Ni and 25 at% Fe has been studied at 800-900°C under low oxygen pressures. The alloy contains a mixture of a phase α rich in Cu and Ni with little Fe with a phase β rich in Fe and Ni with little Cu. The scaling kinetics show rather large deviations from the parabolic law and are much slower than those of pure Fe and of a binary Cu-25Fe alloy oxidized under the same conditions. The growth of an external layer of iron oxide is coupled to the formation of oxide particles dispersed uniformly within the alloy. The internal oxidation of Fe produces a transformation of the β phase into the Cu-Ni solid solution which becomes the matrix of the internal oxidation zone. The β phase disappears also beneath the internal oxidation front to some depth, producing a single-phase α layer. The spatial distribution of the oxide particles in the alloy is rather uniform and does not correspond to that of the two-phases in the original material, which have a largely different iron content. This is the result of a transformation of the β phase into the α phase and of the lateral diffusion of the various components through the α layer before the arrival of the internal oxidation front.
Magnetic and spectral studies of divalent metal complexes of isonitroso-5-methyl-2-hexanone and its derivative
Donde,Patil,Malve
, (2005)
The metal complexes of isonitroso-5-methyl-2-hexanone (HIMH) and 5-methyl-2,3-hexanedione dioxime (H2MHDDO) with Fe(II), Cu(II) and Hg(II) have been synthesized. Their structures have been investigated by using elemental analyses, electrical co
Self-propagating high-temperature synthesis of nonstoichiometric wüstite
Hiramoto, Maki,Okinaka, Noriyuki,Akiyama, Tomohiro
, p. 59 - 64 (2012)
This paper describes the self-propagating high-temperature synthesis (SHS) of nonstoichiometric FexO (x = 0.833-1), with particular focus on the effects of nonstoichiometric Fe content and diluent addition on the phase of the SHS product. In th
Combined hydrogenation of carbon oxides on catalysts bearing iron and nickel nanoparticles
Sheshko,Serov
, p. 51 - 54 (2011)
The reaction of the hydrogenation of a mixture of carbon oxides on ultradisperse powder (UDP) catalysts containing Fe and Ni nanoparticles and their bimetallic mechanical mixtures was investigated. It was established that the main reaction product on UDP
Potassium-promoted iron oxide model catalyst films for the dehydrogenation of ethylbenzene: An example for complex model systems
Ketteler, Guido,Ranke, Wolfgang,Schloegl, Robert
, p. 104 - 111 (2002)
The stability ranges of potassium-promoted iron oxide model catalyst films were studied in dependence on the annealing temperature and oxygen partial pressure using scanning tunneling microscopy (STM) and AES. In agreement with the stability ranges of potassium-promoted iron oxide model catalyst films prepared on a Pt(111) substrate, the same KFeO2 phase formed at 700 K, while at higher temperatures single-crystalline KxFe22O34(0001) became more stable. The Ru(0001) substrate enabled the growth of thinner closed films than on Pt(1 H), leading to sufficient conductivity of the insulating KFeO2 film image this surface with STM. The catalytic dehydrogenation of ethylbenzene was carried out at 870 K, and a depletion of potassium at this temperature was observed, leading to the single crystalline KxFe22O34(0001) phase.
Direct evidence for the interfacial oxidation of CO with hydroxyls catalyzed by Pt/oxide nanocatalysts
Xu, Lingshun,Ma, Yunsheng,Zhang, Yulin,Jiang, Zhiquan,Huang, Weixin
, p. 16366 - 16367 (2009)
(Graph Presented) By rational design of the FeO(111)/Pt(111) inverse model catalyst and the control experiments, we report for the first time direct experimental evidence for the interfacial COads + OHads reaction to produce CO2
Subramanian, M. A.,Rao, G. V. Subba
, p. 329 - 336 (1980)
Application of thermal analysis to study smelting reduction kinetics
Basu, Projjal,Ray
, p. 1533 - 1540 (1996)
A thermal analysis study on the reduction of iron oxide rich slags under different conditions is presented in this paper. The effects of important process variables such as time, temperature, lime-silica ratio, FeO level in slag etc. are discussed. It is shown that the mechanism of reduction by externally added graphite is different from that by a carbon saturated bath although the activation energy values are similar.
Effect of Fe substitution on multiferroic hexagonal YMnO3
Zaghrioui,Grenche,Autret-Lambert,Gervais
, p. 509 - 514 (2011)
Polycrystalline YMn1-xFexO3 (x=0.020.20) powders were synthesized by means of modified citrate method. Powder X-ray diffraction gives evidence that all the samples are single phase and exhibit hexagonal structure with P6s
Exchange bias and anomalous vertical shift of the hysteresis loops in milled Fe/MnO2 material
Passamani,Larica,Marques,Proveti,Takeuchi,Sanchez
, p. 11 - 20 (2006)
The present article reports studies on structural and magnetic properties of nanostructured Fe/MnO2 materials prepared by mechanosynthesis method, with Fe to MnO2 ratios of 20/80, 50/50 and 60/40. X-ray diffraction patterns indicate that the milled materials have crystalline grain size in the nanoscale region. M?ssbauer spectra of the milled materials suggest the presence of two Fe phases for each sample: a nanocrystalline α-Fe phase with a high degree of disorder/defects and small Fe-oxide particles. The magnetic hysteresis (M(H)) loops, measured at 4.2 K, after the samples were cooled from 300 K in ±10 kOe fields, show unexpected large shifts in both horizontal and vertical directions for the 20/80 sample, while only horizontal shift was detected in the samples with higher Fe concentration. The anomalous vertical shift of the M(H) loop for the 20/80 sample, observed at low cooling field (10 kOe), is being associated with a large contribution from non-collinear magnetic structure of the particles surface. This surface magnetic contribution is strongly influenced by the field cooling magnitude. A simple model is proposed to interpret this result.
Development and structure elucidation of new VO2+, Mn2+, Zn2+, and Pd2+ complexes based on azomethine ferrocenyl ligand: DNA interaction, antimicrobial, antioxidant, anticancer activities, and molecular docking
Aljohani, Enas T.,Shehata, Mohamed R.,Alkhatib, Fatmah,Alzahrani, Seraj Omar,Abu-Dief, Ahmed M.
, (2021/02/26)
An organometallic azomethine ferrocenyl ligand (FCAP) and its transition metal complexes ([M (FCAP)2], where M = VO2+, Mn2+ cations, and [M (FCAP) (CH3COO? or NO3?)], where M = Zn2+/s
Spectroscopic studies, DFT calculations, thermal analysis, anti-cancer evaluation of new metal complexes of 2-hydroxy-N-(4-phenylthiazol-2-yl)benzamide
Emara, Adel A. A.,Mahmoud, Nelly H.,Rizk, Mariam G.
, (2021/08/06)
2-Hydroxy-N-(4-phenylthiazol-2-yl)benzamide was reacted with Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Ag(I) metal ions to synthesize the corresponding coordination compounds. From the study, 2-hydroxy-N-(4-phenylthiazol-2-yl)benzamide was rearranged to 2-hydroxy-N-(4-phenyl-1,3-thiazole-2-yl)carboxymidic acid (HL) due to the keto-enol tautomeric forms, where the enol form is more dominant. The structures of the HL ligand and the newly synthesized coordination compounds have been characterized by elemental analysis, IR, UV-Visible, 1H NMR, ESR and mass spectral data, in addition to thermal gravimetric analysis (TGA) and magnetic and molar conductance measurements. The ligand behaves as a monobasic bidentate ON sites, where the bidentate binding of the ligand involving the phenolic oxygen and azomethine nitrogen. The binding modes of the coordination compounds were further confirmed using Gaussian 09 software. The complexes of Co(II), Cu(II), Zn(II), and Ag(I) were tested in vitro against human colon carcinoma cells (HCT-116). The IC50 values showed dramatic toxicity results for cobalt(II), copper(II) and zinc(II) complexes versus human colon carcinoma (HCT-116) cell line, compared to African green monkey kidney (VERO) normal cell line. According to the results of the IC50 values obtained for Co(II), Cu(II), Zn(II), and Ag(I) 1.5, 1.0, 1.8 and 7.3 μg/ml, respectively, compared to the reference drug (2.49 μg/ml), Co(II), Cu(II), Zn(II) compounds are considered strong antitumor agent while Ag(I) compound can be considered as a weak one. For both antifungal and antibacterial activities, HL and all its coordination compounds were evaluated. HL ligand has only high activity against B. subtilis and C. albicans while Co(II) and Zn(II) compounds have the highest activity against S. aureus, P. aeruginisa, B. subtilis and E. coli.
