Copper Cyanide Complexes Research Articles

Metal ion capillary zone electrophoresis with direct UV detection: Separation of metal cyanide complexes

AbstractMixtures of cyanide complexes of iron(III), copper(I), iron(II), nickel(II), chromium(III), mercury(II), palladium(II), silver(I), cadmium(II), zinc(II), cobalt(II), and cobalt(III) have been separated by capillary zone electrophoresis using a fused silica capillary and 20 mM phosphate buffers containing 1–2 mM sodium cyanide. The complexes were detected by direct UV absorpticn at 214 nm; detection limits are in the mid ppb range for all metals except cadmium and zinc. The different detectability of various metal cyanide complexes enables the application of the method to the analysis of complex matrices such as cyanide plating bath solutions.

Crystal structure of a novel copper(I) cyanide complex with hexamethylenetetramine, (CuCN)3(C6H12N4)2

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure of a novel copper(I) cyanide complex with hexamethylenetetramine, (CuCN)3(C6H12N4)2Fred B. StockerCite this: Inorg. Chem. 1991, 30, 7, 1472–1475Publication Date (Print):April 1, 1991Publication History Published online1 May 2002Published inissue 1 April 1991https://doi.org/10.1021/ic00007a009RIGHTS & PERMISSIONSArticle Views263Altmetric-Citations30LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (504 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Determination of gold using anion‐exchange‐based chemically modified electrodes

AbstractThe determination of gold by the application of electrodes modified with anion exchangers is considered. Particular attention is paid to investigating the capability of these electrodes to determine gold(III) in the presence of copper(II). Electrodes modified with a film of poly(4‐vinyl‐pyridine) or either chemisorbed electrochemically generated were investigated. It was found that copper(II) caused little or no interference in chloride media. However, copper(II) cyanide complexes interfered with the determination of gold cyanide solutions.

ETHYL CARBAMATE FORMATION IN GRAIN BASED SPIRITS: PART I: POST-DISTILLATION ETHYL CARBAMATE FORMATION IN MATURING GRAIN WHISKY

Distilled spirits are subject to post-distillation ethyl carbamate formation in the presence of appropriate precursors. Freshly distilled grain whisky, produced by the continuous distillation Coffey still process, normally contains ethyl carbamate concentrations not exceeding 20 ppb (normalized to 43% v/v alcoholic strength). Further ethyl carbamate formation, dependent upon the presence of trace anionic precursors such as cyanate, cyanide, and copper cyanide complexes, may take place during normal maturation in oak casks. Related but different mechanisms may induce ethyl carbamate formation under normal daylight and artificial light in the laboratory. Ethyl carbamate precursors convert into ethyl carbamate during the initial three months of maturation and are not detectable in the final bottled product. Thus the final ethyl carbamate concentration in spirit is dependent upon the initial ethyl carbamate level measured after distillation plus ethyl carbamate formed from precursors. It is important during process control to monitor not only the ethyl carbamate level in freshly distilled spirit but also the spirit's potential to form ethyl carbamate from precursors with the objective of minimizing these components in the freshly distilled and maturing spirit. A scheme for predicting final ethyl carbamate concentrations from precursor concentrations in freshly distilled spirit is presented.

ETHYL CARBAMATE FORMATION IN GRAIN BASED SPIRITS: PART II THE IDENTIFICATION AND DETERMINATION OF CYANIDE RELATED SPECIES INVOLVED IN ETHYL CARBAMATE FORMATION IN SCOTCH GRAIN WHISKY

Ion chromatographic procedures are described for the identification and determination of a series of cyanide related precursors involved in ethyl carbamate formation in maturing grain whisky produced by the continuous distillation Coffey still process. These precursors include cyanide and copper cyanide complex anions, lactonitrile and isobutyraldehyde cyanohydrin (collectively determined as “measurable cyanide” or MC) and cyanate and thiocyanate anions. The components comprising MC may be determined individually using a pre-chromatographic separation procedure based on anion exchange resins. These techniques have been shown to be applicable for monitoring precursors involved in post-distillation ethyl carbamate formation in maturing grain whisky. Similar ion chromatographic procedures are described for the detection of a range of copper salts, incorporating cyanide, cyanate and thiocyanate, which are naturally occurring deposits within the copper Coffey still. These results are correlated with those based upon X-ray diffraction and secondary ion mass spectrometric techniques. Species identified included cuprous cyanide, cuprous thiocyanate, cuprous oxide, cuprous and cupric sulphide and copper cyanide cluster ions such as CuCN−, Cu(CN)2−, Cu2(CN)3− and Cu3(CN)4− and mixed species Cu(CN)2S−, CuSCN− and CuCNO+. In addition, an ion chromatographic procedure developed to investigate the role of carbamyl phosphate in ethyl carbamate formation, showed that conversion took place by means of its thermal decomposition into cyanate ion.

The role of redox in the regulation of manganese-containing superoxide dismutase biosynthesis in Escherichia coli.

The manganese-containing superoxide dismutase in Escherichia coli is an inducible enzyme that protects cells against oxygen toxicity. The manganese-enzyme is induced by oxygen, nitrate, redox active compounds that react with oxygen to generate superoxide radicals, as well as iron chelators. In order to test the hypothesis that the redox state of the cell is involved in regulating manganese-superoxide dismutase biosynthesis, we studied the effects of several oxidants on growth and superoxide dismutase biosynthesis. The data showed, that under anaerobic conditions, the active manganese-enzyme is induced in the presence of potassium ferricyanide, copper-cyanide complex, ammonium persulfate, and hydrogen peroxide. Western blot analysis revealed that the induction of manganese-superoxide dismutase by the oxidants is associated with de novo protein biosynthesis. Potassium ferricyanide and hydrogen peroxide induced the enzyme under aerobic conditions as well. It is concluded that the redox state of the cell possibly influences the biosynthesis and/or activity of an iron-containing repressor protein that serves to negatively regulate manganese-superoxide dismutase biosynthesis.

Investigation into the ion exchange of the cyanide complexes of zinc(2+), cadmium(2+), and copper(1+) ions

Investigation into the ion exchange of the cyanide complexes of zinc(2+), cadmium(2+), and copper(1+) ions

ChemInform Abstract: Formamide as a Precursor to Cyanide in Mixed‐valence Copper(I,II) Cyanide Complexes.

AbstractThe dehydration of formamide by acetic anhydride forms hydrogen cyanide which reacts with Cu(I) acetate (II) to give simple cyano‐complexes of Cu(I), (I) or (III), and with Cu(II) acetate (V) to produce either a Cu(I) complex (IV) or a mixed‐valence compound (VI), depending on the solvent used.

Formamide as a precursor to cyanide in mixed-valence copper(I,II) cyanide complexes

Copper(I) acetate reacts with acetic anhydride–formamide (1 : 1) in acetonitrile solution to give [Cu2(O2CMe)(CN)] or [Cu2(CN)2(NCMe)]. Anhydrous copper(II) acetate reacts with the same reagent to give [Cu(NCMe)4][Cu2(CN)4] and [Cu(O2CMe)2(HCONH2)]. The influence of various polar solvents on the products of the reaction is evaluated. The complex [Cu(NCMe)4)][Cu2(CN)4] reacts with unidentate nitrogen-donor ligands, L, to form [CuL4][Cu2(CN)4](L = pyridine or 4-methylpyridine) or [CuL3][Cu2(CN)4](L = 2-methylpyridine or 2,6-dimethylpyridine). With bidentate nitrogen-donor ligands, L–L, substitution in [Cu(NCMe)4][Cu2(CN)4] gives [Cu(L–L)2(NCMe)][Cu2(CN)4](L–L = 1,2-diaminoethane or 2,2′-bipyridine). The insoluble complex products are obtained in good yield and characterized by microanalysis and spectroscopy (i.r. and visible reflectance). The role of copper ions in promoting the dehydration of formamide by acetic anhydride is assessed.

The Structure of a Novel Copper(I) Cyanide Complex with Dimethylsulphoxide, (CuCN)2.2DMSO

Abstract The title complex has been isolated and its structure determined by X-ray crystallography.

Replacement of Mn(III) with Cu(II) in Bacillus stearothermophilus superoxide dismutase : Similarity of the active site to the zinc site of copper/zinc superoxide dismutase

Copper(II) was substituted for manganese(III) in Bacillus stearothermophilus Mn-superoxide dismutase. The (EPR) spectrum of the Cu(II) is distinctly rhombic, overlapping that of Cu(II) replacing zinc in copper/zinc Superoxide dismutase. The copper-cyanide complex of the bacterial enzyme gives an EPR spectrum nearly identical to the cyanide-copper complex of the Cu/Zn enzyme, indicating three nitrogens as metal ligands. These results support the suggestion that metal coordination in B. stearothermophilus Mn-dismutase is a tetrahedral arrangement of three imidazoles and a carboxylate group and indicate copper as a good spectroscopic probe for studying the active site of Mn- and Fe-superoxide dismutases.

Donnan Membrane Effect-Aided Separation of Metal Cyanide Complexes by Hyperfiltration through Cellulose Acetate Membranes

Abstract Permeation behavior of cyanide complexes of copper, zinc, and silver through cellulose acetate membranes was investigated in the presence of “activating salt” (succinate or polyvinyl sulfate). In hyperfiltration with high-performance membranes (CA-87), both activating salts effectively enhanced the permeability of negatively charged Group Ib metal (I) cyanide complexes (Donnan membrane effect); the phenomenon was caused by selective affinity of these metal cyanide complexes to the membrane phase. However, with low-performance membranes (CA-75) such selective permeations were reduced by a contribution of increased solute-solvent flow, and all the metal cyanide-complexes showed relatively high permeabilities. The polymer-type activating salt, polyvinyl sulfate, did not permeate through the low-performance membrane but showed an effectiveness in enhancing the permeability of the cyanide complexes under low-pressurized conditions. Taking advantage of this, a new technique, a Donnan membrane effect-ai...

IDENTIFICATION OF VARIOUS INTERMEDIATES IN THE REACTION OF CUPRIC IONS WITH CYANIDE IONS BY ESR SPECTROSCOPY. APPLICATION OF A NEW RAPID-FREEZING APPARATUS

Abstract Various intermediates of mononuclear copper(II) cyanide complexes in the reaction of cupric ions with cyanide ions have been first identified by ESR spectroscopy after the use of a newly-constructed rapid-freezing apparatus. The formation of these intermediates has been found to depend primarily on the ratio [CN−]/[Cu2+] and pH values. Possible structures of these intermediate complexes have been estimated by experiments with isotopes and by the application of the “rule of average environment” to their ESR parameters determined.

Copper (I) complexes with some disubstituted acetylenes and dimethylsulphoxide

Twelve copper (I) cyanide, bromide and chloride complexes with disubstituted acetylenes (RR 1C(OH)CCX; R, R 1 = CH 3 or C 2H 5, X = Br, CN or Cl) and dimethylsulphoxide (DMSO) were prepared and characterized. In all cases, the molar ratio of copper to dimethylsulphoxide and disubstituted acetylene was 4:2:1. The 1H NMR, u.v. absorption and i.r. spectra (4000-600 cm −1) of the copper (I) complexes were measured. The elemental analysis and spectral data suggest that the disubstituted acetylene is coordinated to the copper (I) atom via the π-bond using two-electron, three-centre carbon—metal bonds.

Removal of heavy metals from electroplating rinsewaters by precipitation, flocculation and ultrafiltration

Chromium, nickel, copper and zinc can be effectively removed from electroplating rinsewaters by hydroxide precipitation, flocculation and ultrafiltration. Prior to precipitation, chromium is reduced from the hexavalent to the trivalent form by ferrous sulfate and cyanide in copper and zinc rinsewaters are oxidized by sodium hypochlorite. Minimum metal concentrations in the permeate from separate batches of chromium, nickel, copper and zinc rinsewaters were found to be, respectively, 0.17 mg 1 −1 Cr (T), 0.26 mg 1 −1 Ni, 0.30 mg 1 −1 Cu and 1.84 mg 1 −1 Zn. These solubilities are in good agreement with the theoretical solubility curves, except for copper where the formation of stable copper cyanide complexes appears to increase the solubilities at least two orders of magnitude relative to those predicted on the basis of the equilibrium constants for copper hydroxides and oxides. A simple mass balance model, assuming concentrate recycle and constant metal concentration in the permeate, is adequate for the prediction of feed and permeate concentrations as a function of the volume filtered up to a relative volume of about 0.3. Above this value, the feed concentrations are lower than predicted, apparently because of entrapment of metal precipitate in the strainer. Water recoveries are strongly dependent on the specific metal removed and are found to be 24% for Ni with a 0.20 μm membrane, 10% for Cr with a 0.80 μm membrane, 6.5% for Cu and 3.7% for Zn, both with a 0.45 μm membrane.

X-Ray crystal structure of two new mixed-valence copper cyanide complexes: unusual bi-co-ordinated copper(I) atoms in polymeric networks

The two mixed-valence compounds [Cu4I(CN)6CuII(NH3)2]n and [Cu3I(CN)5CuII(NH3)2(OH2)]n display polymeric networks in the solid state and show co-ordination numbers three and two for the copper(I) atoms and four or five for the copper(II) atoms.

Catalytic effect of copper on the hexacyanoferrate(III)-cyanide redox reaction—I: The uncatalysed and catalysed reactions

A kinetic study of the hexacyanoferrate(III)-cyanide redox reaction has been made in connection with development of a new catalytic method for copper. The reaction kinetics change with time from first- to second-order dependence with respect to hexacyanoferrate(III). The reaction is nearly inverse first-order with respect to hexacyanoferrate(II) and first-order with respect to cyanide. The reaction shows a strong positive primary salt effect, but a very small increase in the reaction rate with temperature is found. A parallel reaction proceeds with a first-order dependence with respect to hydroxide. A tentative mechanism is proposed for the first reaction, involving the formation of cyanogen radicals. The second reaction corresponds to the well-known decomposition of hexacyanoferrate(III) in alkaline medium. The catalysed reaction exhibits similar kinetics with respect to hexacyanoferrate(II) and (III) but is zero-order with respect to cyanide and hydroxide and first-order with respect to catalyst. The proposed mechanism involves two consecutive interactions of the hexacyanoferrate(III) with copper(I) and with copper(II) cyanide complexes respectively, followed by a 2-electron oxidation of a co-ordinatively bridging cyanide group.

Stable cyanide complexes of copper(II)

Stable cyanide complexes of copper(II)

Stepwise formation of cyanide complexes of copper(I) in anion exchangers

Stepwise formation of cyanide complexes of copper(I) in anion exchangers

Cyanide Complexes of Copper with Ammonia and Ethylenediamine

Cyanide Complexes of Copper with Ammonia and Ethylenediamine