Showing papers on "Antimony published in 1994"
25 Apr 1994
TL;DR: Nagase et al. as mentioned in this paper described the structural chemistry of organic compounds containing Arsenic, Antimony and Bismuth, and showed that the properties of these compounds are similar to those of As, Sb and Bi.
Abstract: Partial table of contents: General and Theoretical Aspects (S. Nagase). Structural Chemistry of Organic Compounds Containing Arsenic, Antimony and Bismuth (D. Sowerby). Detection, Identification and Determination (T. Crompton). Mass Spectra of the Organometallic Compounds of As, Sb and Bi (Y. Nekrasov & D. Zagorevskii). Substituent Effects of Arsenic, Antimony and Bismuth Groups (M. Charton). Thermochromism of Organometallic Derivatives Containing As, Sb or Bi (H. Breunig). Electrochemistry (M. Nielsen). Thermolysis (C. McAuliffe & A. Mackie). Syntheses and Uses of Isotopically Labelled Compounds of Bismuth, Antimony and Arsenic (M. Zielinski & M. Kanska). The Biochemistry of Arsenic, Bismuth and Antimony (K. Dill & E. McGown). Safety and Environmental Effects (S. Maeda). Indexes.
172 citations
TL;DR: In this article, the Sb-V-O system was used for propane ammoxidation to acrylonitrile and high rate and selectivity for propylene formation at low conversion are characteristic for samples with excess vanadia and considering XRD, Raman, infrared and XPS results, this is explained by formation of amorphous vanadia spread over the surface of SbVO4.
141 citations
TL;DR: The synthesis of the common monodentate and bidentate stibines and bismuthines, and of multidentates containing one or more antimony or Bismuth donor are briefly reviewed in this article.
115 citations
TL;DR: In this article, a dissociative adsorption of formic acid on adatom modified Pt(100) electrodes was carried out as a way of studying inhibition of the poison formation reaction on these surfaces.
108 citations
TL;DR: In this paper, low temperature GC coupled on-line with ICP-MS was used to identify volatile metal and metalloid compounds in gases and condensates from a domestic waste deposit Seven tin species could be identified by external standard addition and further volatile compounds of tin, bismuth, mercury, arsenic, antimony and tellurium could be found by boiling point calibration.
Abstract: Low temperature GC coupled on-line with ICP-MS was used to identify volatile metal and metalloid compounds in gases and condensates from a domestic waste deposit Seven tin species could be identified by external standard addition and further volatile compounds of tin, bismuth, mercury, arsenic, antimony and tellurium could be found by boiling point calibration, respectively Some technical and methodical concepts towards quantification of the results are indicated
92 citations
TL;DR: In this paper, X-ray photo-electron spectroscopy (XPS) analysis was performed on toluene and propane ammoxidation to identify the role of vanadium antimonate catalysts.
Abstract: Unsupported vanadium antimonate catalysts with Sb/V ratios of 1 and 5 and samples with the latter ratio supported on alumina were studied in toluene and propane ammoxidation to benzonitrile and acrylonitrile, respectively, and were characterized by X-ray photoelectron spectroscopy (XPS) analysis before and after catalytic tests. Activity data for toluene ammoxidation suggest that excess antimony with respect to the stoichiometric amount required for forming the VSbO4 rutile phase affects the dispersion of the latter phase giving smaller particles. Vanadium sites are involved both in the activation of toluene and in the insertion of nitrogen in this reaction, whereas antimony does not play a specific role in the reaction mechanism. In propane ammoxidation, on the other hand, due to a higher reaction temperature with respect to toluene (500°C vs. 370°C), free vanadia on the surface of the catalyst has a negative influence on the selectivity because it promotes the conversion of ammonia to nitrogen, decreasing the surface nitrogenous species required for the selective formation of acrylonitrile. Excess antimony is thus necessary for completing the reaction between antimony and vanadium oxides, but antimony also participates in the reaction mechanism. In propane ammoxidation, in fact, XPS data show that both vanadium and antimony sites are reduced. Tentatively, vanadium sites are involved in the activation of propane, while antimony sites insert nitrogen. The differences between the toluene and propane ammoxidation mechanisms are interpreted to be primarily related to the different reaction temperatures.
73 citations
TL;DR: In this paper, the electrical conductivity and optical transmission of tin oxide films were studied with antimony doping and it was found that the film conductivity increased largely without losing optical transparency with a small addition of antimony.
Abstract: Antimony-doped tin oxide films were prepared on Corning glass substrate by chemical vapor deposition from a gas mixture of SnCl4–SbCl5–H2O. The electrical conductivity and optical transmission of tin oxide films were studied with antimony doping. The film conductivity increased largely without losing optical transparency with a small addition of antimony. The increase of the conductivity was attributed mainly to more electrons donated by pentavalent Sb ions in the SnO2 lattice. Large additions of antimony, however, diminished the conductivity, optical transparency, and crystallinity of the film. The diminution was found to be caused by fine Sb2O5 phases codeposited with SnO2.
70 citations
TL;DR: In this article, the correlation between structural and electrical properties of sprayed SnO2 films have been investigated as a function of substrate temperature (380-560 °C), concentration of tin precursor (0.02-0.8 M SnCl4), and the nature of the doping agent (chlorine, fluorine, antimony).
Abstract: The correlations between structural and electrical properties of sprayed SnO2 films have been investigated as a function of substrate temperature (380–560 °C), concentration of tin precursor (0.02–0.8 M SnCl4) and the nature of the doping agent (chlorine, fluorine, antimony). High-resolution transmission electron microscopy has shown that chlorine or fluorine incorporation promotes the same type of defects, which are twins. These latter behave as neutral defects, the density of which limits the carrier mobility of degenerated fluorine- or chlorine-doped films to around 20 cm2 V−1 s−1. The situation is totally different with antimony. Below the solubility limit in the SnO2 lattice (3%–4% Sb/Sn), Sn4+ are substituted by Sb5+, creating two conduction electrons per site and acting as point-charged defects which lower carrier mobility. Above this limit, the Sb3+ and Sb5+ forms coexist and are associated with an extremely large concentration of structural defects, especially twins induced by the Sb3+ species. These ions enter two-dimensional arrangements on both sides of the twins, making them planar charged defects.
64 citations
58 citations
TL;DR: In this article, the electrochemical codeposition of In and Sb from a novel low temperature molten salt electrolyte is reported, which consists of InCl3 and 1-methyl-3ethylimidazolium chloride.
Abstract: The electrochemical codeposition of In and Sb from a novel low temperature molten salt electrolyte is reported. The melt, which consists of InCl3 and 1-methyl-3-ethylimidazolium chloride, allows the codeposition to be accomplished at 45 °C. XPS shows that InSb can be deposited from this system. Electrochemical experiments are provided along with an interpretation that draws on the importance of In(I) species in the melt.
53 citations
TL;DR: In this article, the authors detected volatile species of silicon, vanadium, arsenic, bromine, tin, antimony, tellurium, iodine, mercury, lead and bismuth in gases released from domestic waste deposits, using inductively coupled argon plasma mass spectrometry (ICP MS).
Abstract: We have detected volatile species of silicon, vanadium, arsenic, bromine, tin, antimony, tellurium, iodine, mercury, lead and bismuth in gases released from domestic waste deposits, using inductively coupled argon plasma mass spectrometry (ICP MS). By concurrent aspiration of a multielement standard solution for calibration, the element concentrations in deposit gas are found to be in the range from 0.1 ng m−3 to 10 μg m−3 gas. The global amount of some metal species emitted by this process may be of the order of several tons per year. These results suggest a biogeochemical pathway for the transfer of metals into the atmosphere via volatile species. This process may have significant influence on atmospheric cycling of metals as well as on metal toxicity within ecosystems.
TL;DR: In this paper, the influence of predosed antimony on the adlayer structures of carbon monoxide and on the electrooxidation kinetics of formic acid on Pt(100) and Pt(111) in 0.1M HClO 4 is examined by means of in-situ infrared spectroscopy in conjunction with cyclic voltammetry.
Book•
15 Dec 1994
TL;DR: In this article, the Chalcogens and the Noble Gases are classified as follows: Hydrogen, Alkali and Alkaline Earth Metals, Zinc, Cadmium, and Mercury.
Abstract: Introduction and General Organization. Hydrogen. Carbon. Silicon, Germanium, Tin, and Lead. Nitrogen. Phosphorus, Arsenic, Antimony, and Bismuth. The Chalcogens. Halogen and the Noble Gases. Boron. Aluminum, Gallium, Indium and Thallium. The Alkali and Alkaline Earth Metals. Zinc, Cadmium, and Mercury. Lanthanides and Actinides. Index.
TL;DR: In this article, the photoredox reactivity of antimony(III) porphyrin complexes was investigated and an extended model for the electronic structure of p-type hyper metalloporphyrins was suggested.
Abstract: Observations of the photoredox reactivity of antimony(III) porphyrin complexes are reported. Upon irradiation with visible light under ambient conditions, a photooxidation to the corresponding dihydroxoantimony(V) porphyrins occurs. At the same time a two-electron or four-electron reduction of molecular oxygen takes place, depending on the experimental conditions. In the absence of suitable electron acceptors, a photoinduced disproportionation reaction occurs. The photolysis of antimony(III) porphyrins shows a pronounced wavelength dependence. The reactive excited state is concluded to be of the metal-centered sp type. An extended model for the electronic structure of p-type hyper metalloporphyrins is suggested.
TL;DR: Sb 2 S 3 thin films have been prepared on glass substrates by spray pyrolysis and have been characterised for their structural, optical and electrical properties as mentioned in this paper.
TL;DR: In this article, the effect of adding hydrogen to the carrier-gas flow of a helium microwave plasma torch (MPT) discharge is evaluated in terms of plasma stability, continuum background and helium emission intensities.
TL;DR: The chelating resin Wofatit MK 51, which contains methylaminoglucitol groups, forms complexes with different oxo anions and can react as a weakly basic anion exchange resin this article.
TL;DR: Antimony-vanadium-oxide catalysts were prepared with various Sb/V ratios and were used for propene ammoxidation as discussed by the authors, where a yield of 55% was obtained at 90% of conversion.
Abstract: Antimony-vanadium-oxide catalysts were prepared with various Sb/V ratios and were used for propene ammoxidation. It was observed that antimony in excess of the amount required for forming SbVO4 was required to have a catalyst that is selective to acrylonitrile formation. Characterisation of catalysts with FTIR revealed partial reduction of the oxidised phase Sb0.92V0.92O4 upon use to form Sb0.95V1.05O4. XPS data showed the surfaces of most selective catalysts to be further enriched with antimony in course of the catalytic reaction, thereby creating a surface structure that is selective. For acrylonitrile formation a yield of 55% was obtained at 90% of conversion. In propene oxidation, on the other hand, the yield for acrolein formation was limited to 20% due to consecutive combustion of the aldehyde.
TL;DR: In this article, it has been established that antimony facilitates the appearance of a potential region between 0.8 and 1.2 (1.3) V in which nonstoichiometric is formed.
Abstract: The Pb‐Sb alloy consists of α‐Pb crystals and eutectic phase. On anodic polarization of Pb‐Sb electrodes in these phases are oxidized forming and lead oxides: , , as well as , , . The potential regions of formation of the above phases have been determined through x‐ray diffraction analysis as well as their stability and the effect of antimony on the boundaries of these potential regions. It has been established that antimony facilitates the appearance of a potential region between 0.8 and 1.2 (1.3) V in which nonstoichiometric is formed. This leads to a shift in the potential of oxidation of to from 1.0 V for Pb electrodes to 1.2 (1.3) V for Pb‐Sb ones. The reason for the formation of (which has the same crystal structure as that of or is amorphous) has been investigated. It has been established that antimony has a catalytic effect on the reaction and slows down the rate of reaction . It has been proven experimentally that antimony increases the degree of hydration of lead dioxide from 10% (for Pb electrodes) to 30% (for Pb‐20% Sb electrodes). This leads to the formation of elastic elements in the structure of the corrosion layer which, in their turn, reduce cracking of the corrosion layer.
TL;DR: In this paper, aspects of the coordination chemistry of antimony and bismuth trihalides and phenyl bismith dihalides with phosphine and ether ligands are discussed together with a description of the bonding in these complexes.
Abstract: Aspects of the coordination chemistry of antimony and bismuth trihalides and phenyl bismuth dihalides with phosphine and ether ligands are discussed together with a description of the bonding in these complexes. The bonding model described provides a rationalisation of the coordination geometries and the observed trends in some of the bond lengths and angles.
TL;DR: In this article, it was revealed that antimony refines the eutectic structure by reducing the interflake spacing rather than acting as a modifier, which leads to an extra refinement of the Al-Si structure.
Abstract: On treating aluminium-silicon alloy with 0.2 wt% Sb, it was revealed that antimony refines the eutectic structure by reducing the interflake spacing rather than acting as a modifier. The growth mechanism is similar to the unmodified Al=Si flake structure, giving the relationships of the type ΔT=K1V0.51 and λ=K2V−0.4, where K1 and K2 are constants at high solidification rate, the transition from flake to fibre is observed. However, this transition occurs at lower velocity compared to quench modification of the pure alloy. The high magnitude of undercooling measured with the antimony-treated alloy is attributed to constitutional undercooling, which leads to extra refinement of the Al-Si eutectic structure.
TL;DR: In this article, the growth and microhardness studies of NH 4 Sb 3 F 10 single crystals were carried out using a Vickers diamond pyramid indenter, and the results showed strong anisotropy in the work-hardening coefficient for different orientations.
TL;DR: In this paper, Antimony (III) sulphide thin films have been deposited onto a glass substrate from an aqueous alkaline thioacetamide bath using tartaric acid as a complexing agent.
TL;DR: In this article, the same authors reported crystal structures for four organoantimony(III) halides and a new antimony(V) compound, bis(2′-chlorobiphenyl-2-yl)antimony-V trichloride (5), obtained by oxidising (4) with an excess of chlorine.
TL;DR: In this paper, the authors reported a new related phase, containing only antimony, which is promissing because its ferroelastic properties, and synthesized, crystal growth and structure determination of the original double oxide Sb2WO6 has been performed.
TL;DR: In this article, photoelectron spectroscopy with UV laser light of hv ≈4 eV was used to investigate the electronic level structure of the bismuth and the antimony pentamer anion.
TL;DR: In this paper, the electrochemical behavior of lead, antimony and lead-antimony binary alloys has been studied as a function of sulfuric acid and antimony concentrations in the lead alloy.
TL;DR: In this paper, XRD and Raman data show that a Sb:V ratio above unity is needed to have a catalyst selective for acrylonitrile formation, an effect that primarily is related to the catalyst function for transformation of propylene, an intermediate in propane ammoxidation.
Abstract: V-Sb-O catalysts with different Sb:V ratios were prepared and used for the ammoxidations of propane and propylene. XRD and Raman data show the presence of SbVO4/V2O5 when Sb:V 1. For Sb:V = 1, SbVO4 was the predominant phase. The activity data show that a Sb:V ratio above unity is needed to have a catalyst selective for acrylonitrile formation, an effect that primarily is related to the catalyst function for transformation of propylene, an intermediate in propane ammoxidation, to acrylonitrile. XPS data reveal the superior phase to be SbVO4 with supra-surface Sb-sites formed as a result of migration of antimony from a-Sb2O4 during the catalytic reaction. According to Raman results, pure SbVO4 without the copresence of α-Sb2O4 has a low capability for the conversion of formed propylene to acrylonitrile due to slow reoxidation of active [Sb-O-Sb] sites.
TL;DR: MeSbCl 2 (1 ) and SbCl 3 (1a) give the adduct MeSbCCl 2 ·0.6SbCL 3 ( 1a).