Showing papers on "Oxidation state published in 1975"
118 citations
117 citations
TL;DR: From the reaction of (CH3)3PCH2 and (CH 3)3 PAuCl in the ration 2:1 a cyclic dimer of the formula [(CH3]2P(CH2)2Au]2]2 is obtained, containing two liner CAuC and two tetrahedral PC4 units as components of an eight-membered ring as mentioned in this paper.
78 citations
TL;DR: There are several simple types of reactions which a metal complex, ML, may undergo with a Lewis acid as discussed by the authors, but the description is brief for metal basicity and for ligand abstraction, because the former area is relatively limited.
76 citations
[...]
TL;DR: A very large number of stable copper(1) complexes exist in a variety of stoichiometries, and only in few of these complexes, does the formal coordination number of the metal atom exceed four as mentioned in this paper.
Abstract: Publisher Summary A very large number of stable copper(1) complexes exist in a variety of stoichiometries. In few of these complexes, does the formal coordination number of the metal atom exceed four. Indeed, along with silver(1) and gold(I), it is one of the few oxidation states to exhibit regularly the low coordination numbers two and three. The simple amine and halo complexes isolated from aqueous solution fortuitously contain linear copper(1) ions. As a result, coordination number two is erroneously considered to be a common coordination number for this oxidation state. In fact, two-coordinate complexes are probably outnumbered by the trigonally coordinated complexes, whereas against the vast host of tetrahedral complexes, the two- and three-coordinate complexes are numerically insignificant. Most of the nonradioactive elements of Groups V, VI, and VII coordinate with the metal in this oxidation state, and there is also quite an extensive organometallic chemistry as befits an element of such importance in synthetic organic chemistry.
60 citations
TL;DR: In this article, the vanadium remains in the vanadyl state and is complexed possibly either by oxygen donor groups or by mixed oxygennitrogen donor groups in the peat humic acid.
60 citations
TL;DR: In this paper, high-energy photoelectron (p.e.) spectra have been obtained for a number of compounds of antimony and the binding energies range from 542.9, 533.3 eV for [Et4N][SbF6] to 538.6, 529.0eV for Bun3Sb, but there is little correlation with the formal oxidation state.
Abstract: High-energy photoelectron (p.e.) spectra have been obtained for a number of compounds of antimony. The antimony 3d(,5//2) binding energies range from 542.9, 533.3 eV for [Et4N][SbF6] to 538.6, 529.0 eV for Bun3Sb, but there is little correlation with the formal oxidation state. Assignment of the oxidation state of antimony on the basis of X-ray p.e. data alone is not possible with certainty and even gross structural differences may remain undetected by this method.
43 citations
TL;DR: In this paper, the first cyclic voltammetric curves of both cysteine and cystine adsorb at the Pt electrode according to the Frumkin-Temkin isotherm with the heterogeneity factor f = 51 and 21, respectively.
33 citations
TL;DR: The reversible oxidation of Se-cystine using H2O2 and NaBH4 could be successfully demonstrated by this XPS-technique.
31 citations
22 citations
TL;DR: In this paper, the IR stretching frequencies for new linear metal complexes were reported and correlations were established between oxidation state, coordination number, and the corresponding v(M′M″) stretching frequencies.
TL;DR: In this article, the copper-II catalysed oxidation of ascorbate by molecular oxygen has been re-investigated and the kinetics require that electron transfer from a dinuclear copper-ascorbate complex to dioxygen be invoked as the initial step in the mechanism in nitrate, fluoride and chloride media, the reaction thus being presumed to go through a higher, rather than a lower, oxidation state intermediate.
TL;DR: In this paper, the peak intensity ratios (Kβ5/Kβ1) and the relative intensities of Kβ″ to Kβ5 in different oxidation states of 3d transition metal atoms existing in forms of oxidic compounds were investigated.
Abstract: Using a commercially available flat crystal spectrometer in a slightly modified form, an investigation was made of the peak intensity ratios (Kβ5/Kβ1) and the relative intensities of Kβ″ to Kβ5 in different oxidation states of 3d-transition metal atoms existing in forms of oxidic compounds. The peak intensity ratios (Kβ5/Kβ1) for V, Cr, Mn, Fe, Co, Ni and Cu, as well as the peak profiles of Kβ″ and Kβ5 for V, Cr and Mn, were investigated. Results suggest that changes in the intensities of the Kβ5 and Kβ″ bands can be applied to determining the oxidation number of a metal atom in its oxide.
TL;DR: In this paper, the influence of preparation and treatment conditions on the catalytic activity in propylene disproportionation has been studied on catalysts prepared by interaction of Wπ-C4H7)4 with SiO2.
Abstract: The influence of preparation and treatment conditions on the catalytic activity in propylene disproportionation has been studied on catalysts prepared by interaction of W(π-C4H7)4 with SiO2. The influence of the prehydration temperature of silica gel and the temperature of the treatment of the catalyst with hydrogen has been found to be appreciable. Comparison between the activity of the catalysts and the average oxidation state of tungsten ions suggests that the oxidation state of tungsten ions in the active catalyst component is +4.
TL;DR: In this article, the reaction of copper(I) chloride with oxygen in pyridine results in the formation of a novel copper peroxide complex and copper(II) chloride.
Abstract: The reaction of copper(I) chloride with oxygen in pyridine results in the formation of a novel copper(I) peroxide complex and copper(II) chloride.
TL;DR: In this article, the chemical shift of V Kβ1, 3 and width of V kα1 were measured with a two crystal X-ray spectrometer and applied to vanadium containing catalysts and perovskite structure compounds.
Abstract: The chemical shift of V Kβ1, 3 and width of V Kα1 were measured with a two crystal X-Ray spectrometer. It was found that V Kβ1, 3 shift and V Kα1width can be utilized for identification of the vanadium oxidation state. Applications to vanadium containing catalysts and several perovskite structure compounds are discussed.
TL;DR: In this article, the vibrational frequencies of uranium hexachlorides (UCl6, UCl6− and UCl62−) were assigned on the basis of an Oh point group symmetry, and using the modified Urey-Bradely Force Field and the Molecular Orbital Valence Force Field (MOVFF), a Normal Coordinate Treatment (NCT) was made.
Patent•
23 Jan 1975
TL;DR: In this article, an improvement in the electrodeposition of silver from an aqueous cyanide-free bath is described, which comprises the use organic nitrogen containing compounds having at least two nitrogen atoms and having a molecular weight of at least 300, and a compound of sulfur or selenium in an oxidation state of minus one or minus two.
Abstract: The specification discloses an improvement in the electrodeposition of silver from an aqueous cyanide-free bath which comprises the use organic nitrogen containing compounds having at least two nitrogen atoms and having a molecular weight of at least 300, and a compound of sulfur or selenium in which the sulfur or selenium is in an oxidation state of minus one or minus two. The combination is used as an activator in the bath.
Patent•
25 Jun 1975TL;DR: In this article, the same authors describe a mixture of molybdenum, phosphorus, Mg magnesium, and oxygen, where mg is the atomic ratio of the respective elements.
Abstract: Acrylic acid or methacrylic acid is prepared by vapor-phase catalytic oxidation of acrolein or methacrolein, with molecular oxygen at a temperature of from 240° to 450° C in the presence of a catalyst represented by the formula: Mo.sub.12 P.sub.a Mg.sub.b Q.sub.b.sub.' R.sub.c T.sub.d O.sub.e wherein Mo is molybdenum, P is phosphorus, Mg magnesium, O is oxygen, Q is at least one of calcium, strontium, and barium, R is at least one of potassium, rubidium, cesium and thallium, T is at least one of vanadium, tungsten and nickel, and a, b, c, d, and e are atomic ratios of the respective elements, where a=0.5-6, b=0.2-6, b+b'= 0.2-6, b' ranges from 0 to a value determined by the magnesium content of the catalyst and the limits of b+b', c=0.2-6, d=0-6, and e is a value dependent upon the oxidation state of the catalyst.
TL;DR: Magnesium oxide containing up to 8 atom % iron oxide, with and without lithium oxide, prepared at 1273 K in reducing (CO + CO2) and oxidizing (air) atmospheres, has been investigated by means of lattice parameter measurements, chemical analyses and magnetic susceptibility measurements as mentioned in this paper.
Abstract: Magnesium oxide containing up to 8 atom % iron oxide, with and without lithium oxide, prepared at 1273 K in reducing (CO + CO2) and oxidizing (air) atmospheres, has been investigated by means of lattice parameter measurements, chemical analyses and magnetic susceptibility measurements (98–293 K).Iron oxide and magnesium oxide form MgFe2O4 in air. Addition of lithium enables iron ions to enter into solid solution as Fe3+. In a reducing atmosphere (oxygen partial pressure = 1.013 × 10–7 N m–2= 10–12 atm) the iron is incorporated in MgO as Fe2+. The MgO lattice stabilizes the 2+ oxidation state of iron in solid solution. The effect of the combined action of outgassing and N2O decomposition is discussed.
01 Jan 1975
TL;DR: The three pairs of metals Y, Lu, Zr, Hf; Nb, Ta show a striking resemblance between the lighter and the heavier metal of each pair, arising from the predominant stability of the highest, or group, oxidation state, together with the ionic nature of the bonding and the close similarity of ionic radii as mentioned in this paper.
Abstract: The three pairs of metals Y, Lu; Zr, Hf; Nb, Ta show a striking resemblance between the lighter and the heavier metal of each pair, arising from the predominant stability of the highest, or group, oxidation state, together with the ionic nature of the bonding and the close similarity of ionic radii. Thus both zirconium and hafnium are rather poorly represented in oxidation states other than +4, and the ionic radii are Zr4 + = 74 pm and Hf4 + = 75 pm, leading to chemical properties that differ only in comparatively minor respects. However, hafnium has been investigated to a smaller extent than has zirconium, so the factual basis for the statement that their properties are similar is less complete than might be desirable. The chemistry is relatively straightforward, being mainly that of the 4+ ions. Since these are fairly large, high co-ordination numbers are frequent. There are no known carbonyls but numbers of σ- and π- bonded organometallics have been prepared.
01 Jan 1975
TL;DR: The oxidative addition of alkyl halides is a reaction undergone by coordinatively unsaturated transition metal complexes with con-commitant increase in oxidation number and coordination number as mentioned in this paper.
Abstract: The oxidative addition of alkyl halides is a reaction undergone by coordinatively unsaturated transition metal complexes with concommitant increase in oxidation number and coordination number. In its simplist form, a metal in oxidation state (n) and coordination number (m) adds alkyl halides to give a new complex of oxidation number (n + 2) and coordination number (m + 2) (Equation 1).
[...]
TL;DR: The chemistry of this pair of metals, which have remarkably similar properties, is dominated by their highest possible oxidation state of +5, but not so completely as the +4 state dominates zirconium and hafnium chemistry.
Abstract: The chemistry of this pair of metals, which have remarkably similar properties, is dominated by their highest possible oxidation state of +5, but not so completely as the +4 state dominates zirconium and hafnium chemistry. Thus well-defined lower oxidation states, particularly Nb(IV) and Ta(IV), are found but their chemistry is rather limited. This is also the first pair of heavy transition metals capable of forming typical low-valent π-bonded complexes.
TL;DR: In this paper, the alkyl-silicon bond is cleaved by MoCl5 and WCl6, and the organic radical migrates to the titanium atom when Me3SiPh is reacted with TiCl4.
Abstract: 1.
Compounds of Ti, V, Zr, Mo, and W in the higher oxidation states cleave the Si-Ph bond in Me3SiPh at 20–150°.
2.
The alkyl-silicon bond is cleaved by MoCl5 and WCl6.
3.
When Me3SiPh is reacted with TiCl4 the organic radical migrates to the titanium atom.
TL;DR: Infrared spectra of chloroform and pyridine solutions, corrected for solvation, showed the sequences of acetyl carbonyl stretching frequencies: dipyridine iron(II) less than mu-oxo bisiron(III) more than bromo iron(III).
01 Jul 1975
TL;DR: In contrast with sulfides of lead, zinc, and antimony (III), in the case of activation of tin (IV) sulfide with copper (II) bis-(dithiocarbaminate), the sorbed copper is present in the II oxidation state.
Abstract: 1.
In contrast with sulfides of lead, zinc, and antimony (III), in the case of activation of tin (IV) sulfide with copper (II), the sorbed copper is present in the II oxidation state.
2.
When diethyldithiocarbaminate reacts with copper sorbed by SnS2, paramagnetic hydrophobic compounds which are firmly attached to the sulfide surface are formed.
The compound readily desorbed by chloroform is copper (II) bis-(dithiocarbaminate). The surface compound not desorbed by chloroform also has a chelate structure and apparently corresponds to a copper (II) compound, the coordination sphere of which is formed by two sulfur atoms of dithiocarbaminate and two sulfur atoms of the SnS2 surface.
3.
By the example of carboxylic and α-hydroxycarboxylic acids, the authors show the relation between the selectivity of the effect of chelate-forming reagents and the type of their attachment to the mineral surface under flotation conditions.