Showing papers on "Ferric published in 1970"
408 citations
TL;DR: In this article, the adsorption of water, ethanol, ammonia, and piperidine on the oxidized iron zeolite is discussed in terms of the proposed model.
185 citations
01 Jan 1970
185 citations
TL;DR: The enzyme activity is assayed by measuring the increase in optical density at 375 m μ due to the formation of the reaction product, α -hydroxymuconic ɛ-semialdehyde, and the activity may be assayed polarographically by measure the oxygen consumption.
Abstract: Publisher Summary This chapter discusses the assay, purification, and properties of metapyrocatechase. The enzyme activity is assayed by measuring the increase in optical density at 375 m μ due to the formation of the reaction product, α -hydroxymuconic ɛ-semialdehyde. The activity may be assayed polarographically by measuring the oxygen consumption. One unit of enzyme is defined as the amount that oxidizes 1 micromole of catechol per minute at 24°. Specific activity is expressed as units per milligram of protein. The enzyme is easily inactivated by various oxidizing agents, such as air or H 2 O 2. This inactivation appears to be due to the oxidation of ferrous ion to the ferric form. The pH optimum for the enzyme activity is 6.5. Molar extinction coefficient of the product at 375 m μ is approximately 2.3 x 10 5 at pH 6.5. Enzyme activity is inhibited by a variety of nitrogen containing aromatic compounds, including o -phenanthroline, m -phenanthroline, quinoline, and pyridine.
180 citations
TL;DR: The structure of the oxygenated heme group of oxyhemoglobin may be formulated as [Hb(Heme d(1/2) (5)).OO(-)].
Abstract: The structure of the oxygenated heme group of oxyhemoglobin may be formulated as [Hb(Heme d(1/2) (5)).OO(-)]. The heme iron atom is formally ferric, and the ligand is bound superoxide anion. When deoxyhemoglobin combines reversibly with oxygen a partial transfer of an electron occurs from the ferrous iron atom to the oxygen molecule. By surrendering its electron the iron atom has become ferric; in accepting an electron the ligated oxygen molecule has become a new species, the bound superoxide anion (.OO(-)). The configuration of the heme iron atom is deduced from comparison of the optical spectrum in the visible region of oxyhemoglobin with that of alkaline ferric hemoglobin whose configuration is established by electron paramagnetic resonance spectroscopy. The configuration of both species is low spin ferric heme iron (Heme d(1/2) (5)). The configuration of the ligated oxygen molecule of oxyhemoglobin is not accessible to study by magnetic or optical probes. However it may be known by analogy with the configuration of the ligated oxygen molecule of reversibly oxygenated cobalt complexes whose structure has been proved by both electron paramagnetic resonance and x-ray diffraction analysis. It is bound superoxide anion (.OO(-)). Other physical studies bearing on the structure of the oxygenated heme group are discussed. Reasons are given for believing that the proposed formulation of the oxyhemoglobin structure is consistent with the known stability of oxyhemoglobin.
100 citations
TL;DR: Addition of iron, as a ferric metal chelate (iron ethylenediaminedihydroxyphenylacetic acid), to the growth medium overcame the interference of zinc.
Abstract: Zinc interfered with translocation of iron from roots to above ground parts of Glycine max. (L.) Merrill var. Hawkeye. During periods in which zinc impeded iron translocation, it also suppressed the production of reductant by roots. Addition of iron, as a ferric metal chelate (iron ethylenediaminedihydroxyphenylacetic acid), to the growth medium overcame the interference of zinc. In the root epidermis, potassium ferricyanide formed a precipitate (Prussian blue) with ferrous iron derived from the previously supplied iron ethylenediaminedihydroxyphenylacetic acid. The reduction of ferric iron was suppressed by zinc.
97 citations
TL;DR: In this paper, the electrochemical reduction of oxygen and hydrogen peroxide at the ferric phthalocyanine-graphite electrode was investigated over a wide range of pH values by linear sweep voltammetry in order to characterize the catalyst system.
Abstract: When deposited on graphite, ferric phthalocyanine has been found to be a good catalyst for electrochemical oxygen reduction in near neutral isotonic saline electrolytes (pH 7.22). In this study, the electrochemical reduction of oxygen and hydrogen peroxide at the ferric phthalocyanine‐graphite electrode was investigated over a wide range of pH‐values by linear sweep voltammetry in order to characterize the catalyst system. The results are compared with those at platinized platinum and graphite electrodes. The activity of the ferric phthalocyanine‐graphite electrode is approximately equal to that of the platinized platinum electrode in . In acid solution, the ferric phthalocyanine‐graphite electrode has a fair activity but becomes inactive once a fairly negative potential is imposed.
69 citations
TL;DR: In this article, the size distribution of micro-crystalline ferric oxide with the extent of calcination and type of silica gel used were observed, which may be interpreted as reaction with the alumina, or bimodal size distribution distribution of the micro crystallite, or both.
51 citations
Journal Article•
46 citations
TL;DR: In this paper, the Mossbauer spectra of several dioctahedral and trio-complementary micas have been obtained and subjected to detailed computer analysis, showing a tendency for ferrous iron to occupy the larger, more symmetric octahedral site in preference to the smaller, less symmetric site, confirming predictions made on the basis of structure alone.
Abstract: Well-resolved Mossbauer spectra of several dioctahedral and trioctahedral micas have been obtained and subjected to detailed computer analysis. Most of the spectra can be resolved into two ferrous quadrupole doublets and one ferric quadrupole doublet. In dioctahedral micas, ferrous iron is seen to occupy the larger, more symmetric octahedral site in preference to the smaller, less symmetric site, confirming predictions made on the basis of structure alone. In trioctahedral micas there is still a tendency for ferrous iron to occupy preferentially the more symmetric octahedral site even though the two octahedral sites are no longer distinguished by size. A lithium-rich biotite gives a spectrum typical of that expected from a mica with a zinnwaldite structure, but the spectrum of a more authenticated zinnwaldite could not be resolved sufficiently for detailed structural interpretation. The spectra of pyrophyllite and talc give results that can be related to the corresponding micas by considering their respective structural differences. In none of the micas studied was there evidence of ferric iron in tetrahedral coordination. The ferrous: ferric ratios obtained from the Mossbauer spectra do not always agree with the chemical values. In several cases the spectra show more ferrous iron than found chemically. It is suggested that the spectral values are more accurate, oxidation on chemical analysis being the most likely source of error.
45 citations
TL;DR: In this paper, the structural formulae of the oxidized and altered micas were calculated on the basis of 44 + z valiencies, where z is a charge difference between the original and altered mica, and depends mainly on the degree of oxidation of iron.
Abstract: Studies of the structural formulae of Canadian micas indicate that the anionic framework of most natural micas differs from that of ideal mica in the quantity and/or charge of the anions per unit cell. Seven chemically analysed micas having variable chemical properties were chosen for heating experiments under controlled laboratory conditions. Ferric and ferrous iron, water and fluorine were determined after heating. The structural formulae of the oxidized and altered micas were calculated on the basis of “44+z” valiencies whre “z” is a charge difference between the original and altered mica, and depends mainly on the degree of oxidation of iron.
TL;DR: In this paper, it is suggested that due to the adsorption of oxalate anions by the hydroxide, via solution formation of goethite is inhibited whereas the direct hematitization of the amorphous hydroxides particles is not.
Patent•
20 Jul 1970
TL;DR: In this article, the authors presented a scheme to produce a deterministic FERRIC CHLORIDE solution with free oXYGEN at a very high temperature of about 250-400 F.
Abstract: THIS INVENTION IS DIRECTED TO THE OXIDATION OF FERROUS CHLORIDE IN LIQUID AQUEOUS SOLUTION, SUCH AS WASTE HC1 PICKLE LIQUOR, TO A SOLUTION CONTAINING FERRIC CHLORIDE BY INTIMATELY INTERMINGLING SAID FERROUS CHLORIDE SOLUTION WITH FREE OXYGEN (1) IN THE PRESENCE OF A DISSOLVED PROMOTER CATION SELECTED FROM THE CLASS OF AMMONIUM, CHROMIUM, COBALT, COPPER, MANGANESE, NICKEL, ZINC OR MIXTURES THEREOF AT AN ELEVATED TEMPERATURE OR (2) IN THE ABSENCE OF PROMOTER, AT SUPERATMOSPHERIC PRESSURE AND AT A TEMPERATURE OF AT LEAST ABOUT 175*F., FOR A TIME SUFFICIENT TO OBTAIN A FERRIC CHLORIDE CONTAINING SOLUTION. A MIXTURE OF AMMONIUM IONS AND CUPRIC IONS IS THE PREFERRED PROMOTER. THE INVENTION IS ALSO DIRECTED TO PRODUCING HYDROCHLORIC ACID FROM THE FERRIC CHLORIDE SOLUTION OBTAINED BY THE AFORESAID OXIDATION PROCESS BY THE SOLUTION AT A TEMPERATURE OF ABOUT 250-400* F. TO OBTAIN A HC1 GAS-WATER VAPOR OVERHEAD AND A BOTTOMS AQUEOUS SLURRY OF IRON OXIDE.
TL;DR: Mossbauer spectra were obtained for three samples of a complex borosilicate glass which contained varying amounts of iron as mentioned in this paper, and the results indicated that Fe 3+ is present as a glass former in surroundings with tetrahedral symmetry, and that the Fe 2+ ions are exposed to widely varying electric field gradients.
Abstract: Mossbauer spectra were obtained for three samples of a complex borosilicate glass which contained varying amounts of iron. Ferric and ferrous ions were present with isomet shifts of 0.07 mm/sec and 0.80 mm/sec, respectively, relative to a Co in Cu source. The quadrupole splittings were 0.69 mm/sec for Fe 3+ and 2.08 mm/sec for Fe 2+ . The results indicate that Fe 3+ is present as a glass former in surroundings with tetrahedral symmetry, and that the Fe 2+ ions are exposed to widely varying electric field gradients.
TL;DR: A method of preparing stage 1 graphite ferric chloride with 97 per cent of the theoretical composition of C61FeCl3 is described in this article, where the solvent action of acetone on the product has been shown to completely empty a certain fraction of the spaces.
TL;DR: In this paper, the behavior of different iron salts (FeSO4.7 H2O, FeC2O4.2 H 2O, Mohr's salt, and basic iron carbonate) was studied by means of the emanation method, DTA and dilatometry.
Abstract: The behaviour of different iron salts (FeSO4.7 H2O, FeC2O4.2 H2O, Mohr's salt, and basic iron carbonate) was studied by means of the emanation method, DTA and dilatometry. The salts were heated within the temperature range of 20 to 1100‡ C, under identical conditions. The results obtained are compared and the process of thermal decomposition of the different salts is discussed. The “activity” of ferric oxide obtained by decomposition of various iron salts is estimated, and it is suggested that the low “activity” of the sulphate-derived ferric oxides is related to a low thermal annealing rate, while the higher “activities” of the other two resultant ferric oxides are similarly related to higher thermal annealing rates.
TL;DR: Both ferri-schizokinen and 2,3-dihydroxybenzoate plus iron enhanced considerably the otherwise minimal repressive effects of iron at low concentrations.
Abstract: Excretion of the metal-chelating phenolic acid, 2,3-dihydroxybenzoate, by a tryptophan-requiring strain (M-13) of Bacillus subtilis was inversely proportional to the iron added to the medium. Addition of iron as the ferric chelates of two secondary hydroxamates (ferri-schizokinen and Desferal) markedly reduced excretion. Synthesis of 2,3-dihydroxybenzoate from chorismate by extracts of B. subtilis M-13, grown in low-iron medium, was unaltered by additions of FeSO4, FeCl3, ferrischizokinen, 2,3-dihydroxybenzoate, the 2,3-dihydroxybenzoate-iron complex, or by extracts of cells grown in high-iron medium (which contained no demonstrable 2,3-dihydroxybenzoate-synthesizing activity) to the extracts of “low-iron cells.” Iron control seemed to involve repression of synthesis of the enzymes in the 2,3-dihydroxybenzoate pathway. Both ferri-schizokinen and 2,3-dihydroxybenzoate plus iron enhanced considerably the otherwise minimal repressive effects of iron at low concentrations. Ferri-schizokinen delayed derepression of the pathway in B. subtilis M-13, and reduced its rate of synthesis after derepression. Addition of FeSO4 to derepressed cells of B. subtilis M-13 halted synthesis of the enzymes after a lag period. The effect of the ferric hydroxamates was related to the capacity of B. subtilis M-13 to incorporate 59Fe3+ from Desferal-59Fe3+. Cellular accumulation of 59Fe3+ from Desferal-59Fe3+ after 20 min was nearly double that incorporated from 59FeCl3.
Patent•
ARCO1
TL;DR: In this paper, a process for the polymerization of acrylonitrile is provided using a catalyst which contains an iron source, an electron donor ligand, and a reducing agent, in molar ratios of (B) to (A) of about 0.3 to 10:1.
Abstract: A process for the polymerization of acrylonitrile is provided using a catalyst which contains (A) an iron source, (B) an electron donor ligand, and (C) a reducing agent, in molar ratios of (B) to (A) of about 0.3 to 10:1 and of (C) to (A) of about 3 to 50:1. Preferred catalyst components are ferric acetylacetonate, bis(diphenylphosphino)-ethane and triethylaluminum.
Patent•
15 Apr 1970TL;DR: In this paper, the authors describe a contraction of a WATER SOLUBLE REDUCTANT for a period of time in the presence of ACTIVITATED CARBON as a CATALYST to minimize the FERRIC ION CONTENT THEREOF WHILE SUBSTANTIALLY COMPLETELY CONSUMING the ACTIVE IONS of the REDUCTant.
Abstract: FERRIC SULFATE-SULFURIC ACID LEACHING OF NATURALLY OCCURRING, COPPER-BEARING MATERIALS, SUCH AS COPPER MINERALS IN MINE WASTE DUMPS, AND RECOVERY OF THE DISSOLVED COPPER BY PRECIPITATION ON METALLIC IRON ARE CARRIED OUT ON A CYCLIC BASIS, WITH REDUCTION OF FERRIC IONS PRIOR TO THE COPPER PRECIPITATION STEP. THE PREGNANT LEACH SOLUTION IS TREATED WITH A CONTROLLED QUANTITY OF A WATER SOLUBLE REDUCTANT, SUCH AS SULFUR DIOXIDE OR AMMONIUM-BISULFITE, FOR A SUFFICIENT PERIOD OF TIME IN THE PRESENCE OF ACTIVITATED CARBON AS A CATALYST TO MINIMIZE THE FERRIC ION CONTENT THEREOF WHILE SUBSTANTIALLY COMPLETELY CONSUMING THE ACTIVE IONS OF THE REDUCTANT SO WASTEFUL CONSUMPTION OF THE IRON PRECIPITANT WILL BE PREVENTED WHILE INSURING MOST EFFECTIVE PRECIPITATION OF THE COPPER, AND SO AS ALSO TO PROVIDE NOURISHMENT, WHEN AMMONIUM BISULFITE IS EMPLOYED AS THE REDUCTANT, OF IRON-OXIDIZING BACTERIA NORMALLY PRESENT IN THE LEACH SOLUTION.
TL;DR: An analysis of the background infrared spectrum of an Fe2O3 disc reveals a doublet at 2865 and 2680 cm−1 which has been tentatively assigned to the presence of a proton located near symmetrically between two surface oxide ions.
TL;DR: The Paint Pots, a group of mineral springs in Kootenay National Park, British Columbia, produce acid water with a high content of Fe, Zn, Mn, and Pb, derived from sulfide mineralization in the Cambrian rocks of the area as discussed by the authors.
Abstract: The Paint Pots, a group of mineral springs in Kootenay National Park, British Columbia, produce acid water (pH = 2.5 to 3.5) with a high content of Fe, Zn, Mn, and Pb, derived from sulfide mineralization in the Cambrian rocks of the area. Oxidation of the Fe++ in the water and hydrolysis of the resulting Fe+++ produce a still lower pH in the water, a high redox potential, and a deposit of ferric (oxy) hydroxide. Less than half the available iron, approximately three-quarters of the manganese and zinc, and most of the lead are discharged into the Vermilion River. The strong dilution provided by the high flow rate of the Vermilion River prevents any serious pollution. A simple laboratory test shows that circulation of the acid spring water through crushed limestone will remove all the iron, introduce some oxygen, and reduce both the acidity and the redox potential to normal surface water values. Zinc, manganese, and lead are probably removed incompletely.
Journal Article•
Patent•
16 Nov 1970
TL;DR: In this paper, a method for the recovery of nickel and cobalt from laterite with the elimination of iron was proposed, wherein the laterite is divided into a major and a minor portion and the minor portion is treated with hydrochloric acid to form a suspension.
Abstract: A method for the recovery of nickel and cobalt from laterite with the elimination of iron, wherein the laterite is divided into a major and a minor portion and the minor portion is treated with hydrochloric acid to form a suspension. The major portion of laterite is mixed with the suspension to form a slurry which is roasted to form cobalt and nickel chloride. The nickel and cobalt chlorides are then dissolved by treating the solid residue with water, ferric chloride remaining in the residue. The solution is then subjected to a recovery treatment including cation exchange to separate the cobalt and nickel ions, and reduction to produce cobalt and nickel.
TL;DR: In this paper, the Mossbauer absorption spectra of ferric acetylacetonate irradiated with electrons, were found to be similar to the emission spectra after electron capture in 57 Co labelled Co(AcAc) 3, indicating that an autoradiolysis mechanism is responsible in molecular compounds for the stabilization of the anomalous iron charge states.
TL;DR: In this article, it was shown that the thermal stability of graphite ferric chloride intercalated between the carbon layers is less than that of bulk FeCl 3, due to the presence of trapped C 1 2 trapped in certain spaces in the flake.
TL;DR: Anaerobic, nitrogen-fixing clostridia, with properties that would suit them to the poor and anaerobic conditions of gleyed subsoils, are likely to be the most important iron reducing bacteria.
Abstract: WHEN a soil is flooded or kept waterlogged, iron reduction and gleying begin within a few weeks. So far only organic ligands from various litters have been found to be capable of reducing and bleaching ferric compounds in soil during gleying1,2, but the involvement of certain unknown iron reducing bacteria seems to be more likely, for iron reduction has been found to stop in a submerged soil when bacterial inhibitors are added3. Aerobic as well as anaerobic bacteria, capable of reducing ferric oxide, have been abundant in the soils studied, whether gleying was detectable or not4,5. As far as gleying is concerned, the most important iron reducing bacteria are likely to be the anaerobic, nitrogen-fixing clostridia, with properties that would suit them to the poor and anaerobic conditions of gleyed subsoils. If these nitrogen fixers are implicated in gleying, they should be able to reproduce the characteristic features of gleying, even in laboratory conditions.
Patent•
09 Oct 1970
TL;DR: Soluble iron (III) chelates of N-(2-hydroxybenzyl) substituted aminopolycarboxylic acid ligands are useful in plant nutrition as a source of iron.
Abstract: Soluble iron (III) chelates of N-(2-hydroxybenzyl) substituted aminopolycarboxylic acid ligands useful in plant nutrition as a source of iron.