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Journal articles on the topic 'Rhenium compounds – Oxidation'

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Published: 4 June 2021

Last updated: 8 February 2022

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1

Ionov, A. M., M. R. Kobrin, R. N. Mozhchil, A. S. Sigov, Yu V. Syrov, and V. V. Fomichev. "SYNTHESIS AND STUDY OF RHENIUM(IV) DISULPHIDE." Fine Chemical Technologies 12, no. 6 (December 28, 2017): 83–90. http://dx.doi.org/10.32362/2410-6593-2017-12-6-83-90.

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Synthesis and study of complex chalcogenides in the low oxidation state opens unexpected new opportunities of studying some fundamental problems of condensed matter physics. Dichalcogenides of transition metals, i.e., compounds with the general formula MX2, where M is molybdenum, tungsten, rhenium etc., and X is sulphur, selenium or tellurium, are especially interesting. These dichalcogenides find applications in optoelectronic devices, radiophotonics, in laser physics, communication technology, etc. This study contains a survey of literature concerning the synthesis of sulphides of transition elements from different groups of the Periodic table in low oxidation states. A method of direct hightemperature synthesis of ReS2 from source components has been proposed and implemented. The synthesized compound was identified by the X-ray fluorescence, method of photoelectron spectroscopy and IR absorption spectroscopy. We show that rhenium(IV) disulphide crystallizes in CdI2 structural type. X-ray photoelectron spectroscopy shows that rhenium in the oxidation state of four is present. IR spectrum shows that rhenium(IV) disulphide structure in contrast to molybdenum(IV) disulphide is characterized by a greater deformation of the layers forming the crystal structure.

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2

Leszczyńska-Sejda, Katarzyna, Grzegorz Benke, Joanna Malarz, Mateusz Ciszewski, Dorota Kopyto, Jędrzej Piątek, Michał Drzazga, Patrycja Kowalik, Krzysztof Zemlak, and Bartłomiej Kula. "Rhenium(VII) Compounds as Inorganic Precursors for the Synthesis of Organic Reaction Catalysts." Molecules 24, no. 8 (April 12, 2019): 1451. http://dx.doi.org/10.3390/molecules24081451.

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Rhenium is an element that exhibits a broad range of oxidation states. Synthesis paths of selected rhenium compounds in its seventh oxidation state, which are common precursors for organic reaction catalysts, were presented in this paper. Production technologies for copper perrhenate, aluminum perrhenate as well as the ammonia complex of cobalt perrhenate, are thoroughly described. An ion exchange method, based on Al or Cu metal ion sorption and subsequent elution by aqueous perrhenic acid solutions, was used to obtain perrhenates. The produced solutions were neutralized to afford the targeted aluminum perrhenate and copper perrhenate products in high purity. The developed technologies allow one to manage the wastes from the production of these perrhenates as most streams were recycled. Hexaamminecobalt(III) perrhenate was produced by a newly developed method enabling us to produce a high purity compound in a reaction of spent hexaamminecobalt(III) chloride solution with a perrhenic acid. All prepared compounds are the basis for precursor preparation in organic catalysis.

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3

Collery, Philippe, Didier Desmaele, and Veena Vijaykumar. "Design of Rhenium Compounds in Targeted Anticancer Therapeutics." Current Pharmaceutical Design 25, no. 31 (November 14, 2019): 3306–22. http://dx.doi.org/10.2174/1381612825666190902161400.

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Background: Many rhenium (Re) complexes with potential anticancer properties have been synthesized in the recent years with the aim to overcome the clinical limitations of platinum agents. Re(I) tricarbonyl complexes are the most common but Re compounds with higher oxidation states have also been investigated, as well as hetero-metallic complexes and Re-loaded self-assembling devices. Many of these compounds display promising cytotoxic and phototoxic properties against malignant cells but all Re compounds are still at the stage of preclinical studies. Methods: The present review focused on the rhenium based cancer drugs that were in preclinical and clinical trials were examined critically. The detailed targeted interactions and experimental evidences of Re compounds reported by the patentable and non-patentable research findings used to write this review. Results: In the present review, we described the most recent and promising rhenium compounds focusing on their potential mechanism of action including, phototoxicity, DNA binding, mitochondrial effects, oxidative stress regulation or enzyme inhibition. Many ligands have been described that modulating the lipophilicity, the luminescent properties, the cellular uptake, the biodistribution, and the cytotoxicity, the pharmacological and toxicological profile. Conclusion: Re-based anticancer drugs can also be used in targeted therapies by coupling to a variety of biologically relevant targeting molecules. On the other hand, combination with conventional cytotoxic molecules, such as doxorubicin, allowed to take into profit the targeting properties of Re for example toward mitochondria. Through the example of the diseleno-Re complex, we showed that the main target could be the oxidative status, with a down-stream regulation of signaling pathways, and further on selective cell death of cancer cells versus normal cells.

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4

Herrmann, Wolfgang A., Josef K. Felixberger, Josef G. Kuchler, and Eberhardt Herdtweck. "Alkin-Komplexe des Rheniums in hohen Oxidationsstufen / Alkyne Complexes of Rhenium in High Oxidation States." Zeitschrift für Naturforschung B 45, no. 6 (June 1, 1990): 876–86. http://dx.doi.org/10.1515/znb-1990-0620.

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The class of π-alkyne complexes of metals in medium and high oxidation states has been extended by the type CH3ReO2(RC≡CR′) (3a—i). Exchange of alkyne for oxo ligands under reducing conditions has been employed as a new general synthesis. Compounds 3 are thus obtained by reaction of methyltrioxorhenium(VII) (1) with the alkynes 2a—i in the presence of a ca. 1.1-fold molar amount of polymer-bound triphenylphosphane as reducing agent (desoxygenation). The structural characterization was carried out for the example of the tolan complex 3 e by virtue of a single-crystal X-ray diffraction study at —80 °C, according to which the description of compounds 3 as “rhenacyclopropenes” seems justified. Evidence from NMR investigations of 3 a and 3 c shows that no fast rotation of the respective alkyne ligand around the axis to the metal atom occurs on the NMR time scale up to at least 105 °C. A minimal rotation barrier of approximately 20 kcal/mol is thus to be estimated. Reaction of type 3 compounds (R = R′ = CH3, b; R = R′ = C2H5, c) with polymer-bound triphenylphosphane under more drastic conditions (boiling toluene) for two days effects further reduction, with the dinuclear, diamagnetic rhenium(IV) complexes 4b and 4c, resp., being formed. Sterically demanding alkynes (e.g., R = R′ = Si(CH3)3, C6H5) seem to prevent this type of reaction. According to an X-ray diffraction study, 4b has an equilateral Re2O-triangular core geometry, with the ligands O, CH3, and butyne(2) arranged in such a way that C2-symmetry results. The alkyne complexes reported here are the first ones of tetra- and pentavalent rhenium.

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5

Lupacchini, Massimiliano, Andrea Mascitti, Valentino Canale, Lucia Tonucci, Evelina Colacino, Maurizio Passacantando, Alessandro Marrone, and Nicola d'Alessandro. "Deoxydehydration of glycerol in presence of rhenium compounds: reactivity and mechanistic aspects." Catalysis Science & Technology 9, no. 12 (2019): 3036–46. http://dx.doi.org/10.1039/c8cy02478b.

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6

Savoie, Carole, and Christian Reber. "Near-infrared and visible luminescence and absorption spectroscopy of low-coordinate organometallic rhenium compounds." Canadian Journal of Chemistry 74, no. 1 (January 1, 1996): 28–31. http://dx.doi.org/10.1139/v96-003.

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Low-temperature absorption and luminescence spectra of four organorhenium compounds were measured in the visible and near-infrared spectral regions. Effects of the temperature, formal oxidation state, and the oxo-, bromo-, and organic ligands on the metal center are reported. The emission maxima of the four compounds show a large variation between 9000 and 14 200 cm−1. Stokes shifts show a smaller variation from 3700 to 4200 cm−1. Luminescence intensities are used to qualitatively characterize nonradiative relaxation processes. Key words: luminescence spectra, absorption spectra, organorhenium compounds.

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7

Carvalho, M. Fernanda N. N., Armando J. L. Pombeiro, Gabriele Wagner, Bjørn Pedersen, and Rudolf Herrmann. "Cascade Reaction of Camphor-Derived Diynes with Transition Metal Compounds." Zeitschrift für Naturforschung B 54, no. 6 (June 1, 1999): 725–33. http://dx.doi.org/10.1515/znb-1999-0604.

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Platinum(II) catalyzes the isomerization of camphor sulfonamide diynes in a cascade reaction involving annulation of a five-membered ring to the camphor skeleton, ring-enlargement by C-C bond cleavage, reduction of sulfur(VI) to sulfur(IV), and oxidation of a hydroxy group to a ketone. The reactions of the diynes with other transition metal compounds were also studied. Copper, gold and rhenium give final products similar to those obtained with simple Brønsted acids or halogens, mainly by annulation o f a five-membered ring to the camphor moiety, accompanied by reduction of a sulfonamide to a sulfinamide group, but lacking the ring-enlargement step. Palladium(II) occupies an intermediate position as both types o f products are obtained. The reaction mechanism and intermediates are discussed

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8

Vogler, Arnd, and Horst Kunkely. "Excited state properties of organometallic compounds of rhenium in high and low oxidation states." Coordination Chemistry Reviews 200-202 (May 2000): 991–1008. http://dx.doi.org/10.1016/s0010-8545(99)00241-6.

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9

Murillo, Carlos A. "A Magic Equation: Delta Bonds Plus Bicyclic Guanidinates Equals Strong Reducing Agents." Australian Journal of Chemistry 67, no. 7 (2014): 972. http://dx.doi.org/10.1071/ch13694.

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Reactions of bicyclic guanidinates with dimolybdenum and ditungsten precursors having quadruple bonded units with a σ2π4δ2 (Q) electronic configuration have generated the most easily ionized, chemically stable species and very strong reducing agents. Analogous rhenium compounds have led to the formation of species having dimetal units in unusually high oxidation states. Here we review this chemistry and the accounts that explain such behaviour that has been attributed to the interaction of the π electrons of the guanidinate C(N)3 core with the electrons that give rise to the delta bond of the dimetal units.

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10

Crestini, Claudia, Maria Chiara Caponi, Dimitris S. Argyropoulos, and Raffaele Saladino. "Immobilized methyltrioxo rhenium (MTO)/H2O2 systems for the oxidation of lignin and lignin model compounds." Bioorganic & Medicinal Chemistry 14, no. 15 (August 2006): 5292–302. http://dx.doi.org/10.1016/j.bmc.2006.03.046.

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11

Shul’pin, Georgiy B., Yuriy N. Kozlov, and Lidia S. Shul’pina. "Metal Complexes Containing Redox-Active Ligands in Oxidation of Hydrocarbons and Alcohols: A Review." Catalysts 9, no. 12 (December 9, 2019): 1046. http://dx.doi.org/10.3390/catal9121046.

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Ligands are innocent when they allow oxidation states of the central atoms to be defined. A noninnocent (or redox) ligand is a ligand in a metal complex where the oxidation state is not clear. Dioxygen can be a noninnocent species, since it exists in two oxidation states, i.e., superoxide (O2−) and peroxide (O22−). This review is devoted to oxidations of C–H compounds (saturated and aromatic hydrocarbons) and alcohols with peroxides (hydrogen peroxide, tert-butyl hydroperoxide) catalyzed by complexes of transition and nontransition metals containing innocent and noninnocent ligands. In many cases, the oxidation is induced by hydroxyl radicals. The mechanisms of the formation of hydroxyl radicals from H2O2 under the action of transition (iron, copper, vanadium, rhenium, etc.) and nontransition (aluminum, gallium, bismuth, etc.) metal ions are discussed. It has been demonstrated that the participation of the second hydrogen peroxide molecule leads to the rapture of O–O bond, and, as a result, to the facilitation of hydroxyl radical generation. The oxidation of alkanes induced by hydroxyl radicals leads to the formation of relatively unstable alkyl hydroperoxides. The data on regioselectivity in alkane oxidation allowed us to identify an oxidizing species generated in the decomposition of hydrogen peroxide: (hydroxyl radical or another species). The values of the ratio-of-rate constants of the interaction between an oxidizing species and solvent acetonitrile or alkane gives either the kinetic support for the nature of the oxidizing species or establishes the mechanism of the induction of oxidation catalyzed by a concrete compound. In the case of a bulky catalyst molecule, the ratio of hydroxyl radical attack rates upon the acetonitrile molecule and alkane becomes higher. This can be expanded if we assume that the reactions of hydroxyl radicals occur in a cavity inside a voluminous catalyst molecule, where the ratio of the local concentrations of acetonitrile and alkane is higher than in the whole reaction volume. The works of the authors of this review in this field are described in more detail herein.

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12

Bullock, John P., Eric Carter, Ryan Johnson, Abigail T. Kennedy, Sarah E. Key, Brian J. Kraft, David Saxon, and Patrick Underwood. "Reactivity of Electrochemically Generated Rhenium (II) Tricarbonyl α-Diimine Complexes: A Reinvestigation of the Oxidation of Luminescent Re(CO)3(α-Diimine)Cl and Related Compounds." Inorganic Chemistry 47, no. 17 (September 2008): 7880–87. http://dx.doi.org/10.1021/ic800530n.

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13

Jeitschko, Wolfgang, Horst A. Mons, and Ute Ch Rodewald. "Preparation and Crystal Structure of the Calcium Rhenate(VI, VII) Ca5Re3O15-x." Zeitschrift für Naturforschung B 54, no. 12 (December 1, 1999): 1483–88. http://dx.doi.org/10.1515/znb-1999-1201.

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The title compound was prepared by reaction of elemental calcium with the calcium metaperrhenate Ca(ReO4)2. Its crystal structure was determined from single-crystal X-ray data: Amm2, a = 560.31 (5)pm, b = 1572.4( 1)pm, c = 719.91 (6)pm ,Z = 2 ,R = 0.033 for 930 structure factors and 46 variable parameters. The calcium atoms occupy three atomic sites, all with seven oxygen neighbors. Of the two different rhenium atoms one has square-pyramidal oxygen coordination with an average oxidation number +6.25. The other rhenium site (oxidation number +7) was refined as a split position with trigonal-bipyramidal (75%) and tetrahedral oxygen coordination (25%). One oxygen site remains unoccupied, whenever the tetrahedral rhenium site is occupied, resulting in the composition Ca5Re3O14.75. A test for superconductivity of this black compound down to 1.5 K was negative.

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14

Kraus, Werner, Martin Walther, Christian M. Jung, Franziska Emmerling, and Hans-Jürgen Pietzsch. "Bromotricarbonyl{15-[2-(methylsulfanyl)ethylsulfanyl]pentadecanoic acid-κ2 S,S′}rhenium(I)." Acta Crystallographica Section E Structure Reports Online 62, no. 7 (June 28, 2006): m1660—m1662. http://dx.doi.org/10.1107/s1600536806024081.

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The title compound, [ReBr(C18H36O2S2)(CO)3], was synthesized and characterized as a non-radioactive surrogate of a novel Tc-containing fatty acid derivative prepared according to the tricarbonyl/dithioether design with the objective of developing new Tc-based radiopharmaceuticals for the non-invasive diagnosis of myocardial metabolism. The Re chelate contains the metal in the oxidation state +1 and is attached to the terminal position of a fatty acid. The complex formation was accomplished by a ligand exchange reaction using [NBu4]2[Re(CO)3Br3] as starting material.

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15

Scherer, Otto J., Markus Ehses, and Gotthelf Wolmershäuser. "Notizen: [{Cp*(CI)Re}2(μ-CO)2](Re ≡ Re), ein zweikerniger Rhenium(II)-Komplex mit cis-konfigurierten, terminalen Cl-Atomen/[{Cp*(Cl)Re}2(μ-CO)2](Re ≡ Re), a Dinuclear Rhenium(II) Complex with cis Configuration of the Terminal Cl Atoms." Zeitschrift für Naturforschung B 52, no. 6 (June 1, 1997): 762–65. http://dx.doi.org/10.1515/znb-1997-0615.

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The reaction of [{Cp*(OC)2Re}2](Re = Re) (1), Cp* = C5Me5, with CH2Cl2 yields the dinuclear rhenium complexes [{Cp*(Cl)Re}2(μ-CO)2](Re ≡ Re) (2) with cis orientation of the Cl atoms, [{Cp*(OC)2Re}2(μ-CH2)](Re-Re) (3), a complex with a bridging CH2-carbene ligand, and [{Cp*(OC)2Re}2(μ-C=CH2)]( Re-Re) (4), a μ-vinylidene( alkenylidene) compound. The structure of 2 has been confirmed by a single crystal X-ray structure determination. Starting with [Cp*Re- (CO)2(thf)] (6) instead of 1 the reaction with CH2Cl2 affords cis-[Cp*Re(CO)2(Cl)(CH2Cl)] (7) by oxidative addition of dichloromethane.

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16

Green, Andrew E. C., Laura E. Harrington, and John F. Valliant. "Carborane-carbohydrate derivatives — Versatile platforms for developing targeted radiopharmaceuticals." Canadian Journal of Chemistry 86, no. 11 (November 1, 2008): 1063–69. http://dx.doi.org/10.1139/v08-157.

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A series of carborane-carbohydrate derivatives were prepared as model platforms for developing targeted radiopharmaceuticals in which a single ligand can be tagged with two different classes of radionuclides. A nido-carborane linked to glucose was synthesized and the cage labelled with a radiometal (99mTc) and a radiohalogen (125I) in good radiochemical yield. The 99mTc-metallocarborane derivative was prepared via microwave-assisted reactions, while the iodinated derivative was prepared using oxidative labelling methods in mere minutes. Fully characterized reference standards were prepared using nonradioactive rhenium and iodine and used to demonstrate that the isolated radioactive compounds were in fact the desired targets. The work reported, which is one of the rare examples of a single ligand system that can be labelled with both radiohalogens and radiometals, forms the basis of a new paradigm for developing targeted radiopharmaceuticals.Key words: carboranes, medical isotopes, technetium-99m, iodine-125, glucose.

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17

Sain, Bir, Suman Jain, and Jomy Joseph. "Rhenium-Catalyzed Highly Efficient Oxidations of Tertiary Nitrogen Compounds to N-Oxides Using Sodium Percarbonate as Oxygen Source." Synlett 2006, no. 16 (September 2006): 2661–63. http://dx.doi.org/10.1055/s-2006-951487.

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18

Ara, Irene, Phillip E. Fanwick, and Richard A. Walton. "The oxidative addition of diphenylphosphine and monophenylphosphine to the electron-rich rhenium-rhenium triple bond. The isolation and characterization of compounds that contain the four-center Re(?-X)(?-PR2)Re cluster (X=halide)." Journal of Cluster Science 3, no. 1 (March 1992): 83–102. http://dx.doi.org/10.1007/bf00814613.

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19

Valyaev, Dmitry A., Oleg V. Semeikin, Mikhail G. Peterleitner, Yuri A. Borisov, Viktor N. Khrustalev, Andrei M. Mazhuga, Evgeny V. Kremer, and Nikolai A. Ustynyuk. "Oxidative dehydrodimerization of rhenium vinylidene complex (η5-C5H5)(CO)2ReCC(H)Ph: two competitive routes of coupling of σ-phenylethynyl intermediate [(η5-C5H5)(CO)2ReCCPh]. X-ray structures of rhenium mononuclear (η5-C5H5)(CO)2ReCC(H)Ph and binuclear [(η5-C5H5)(CO)2Re]2(μ2-CC(Ph)CCPh) vinylidene compounds." Journal of Organometallic Chemistry 689, no. 23 (November 2004): 3837–46. http://dx.doi.org/10.1016/j.jorganchem.2004.07.038.

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20

Mckee, Douglas W., and Robert L. Fleischer. "Oxidation Behavior of Advanced Intermetallic Compounds." MRS Proceedings 213 (1990). http://dx.doi.org/10.1557/proc-213-969.

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ABSTRACTThe oxidation behavior of a number of ordered high melting point intermetallic materials has been studied in flowing air in the temperature range 1000 to 1500°C. The alloys were selected for acceptable toughness and ductility at temperatures above 1000°C. Included were ruthenium aluminides, chromium silicide and compounds of iridium and ruthenium with elements such as titanium, tantalum, nickel, iron, cobalt, silicon, vanadium and rhenium. In general, alloys containing the metals iron, cobalt and nickel, and also titanium and tantalum, oxidized rapidly at 1000°C and above. Oxidation-resistant materials were those capable of forming scales of chromia/silica or alumina. Intermetallic compounds of chromium and ruthenium formed volatile oxides above 1200°C, but binary compounds of these elements with silicon and aluminum were highly oxidation resistant at lower temperatures.

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21

Anderson, B. Elizabeth, U. Becker, K. B. Helean, and R. C. Ewing. "Perrhenate and Pertechnetate Behavior on Iron and Sulfur-Bearing Compounds." MRS Proceedings 985 (2006). http://dx.doi.org/10.1557/proc-985-0985-nn12-09.

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AbstractInvestigations on the behavior of the radioactive element technetium frequently use a stable isotope of rhenium as an analogue. This is justified by citing the elements' similar radii, major oxidation states of +7 and +4, and eH-pH diagrams. However, recent studies (e.g.,[1] have shown this analogy to be imperfect. Therefore, one goal of our study is to compare the behavior of these elements with emphasis on the adsorption of perrhenate and pertechnetate (the major forms of Re and Tc in natural waters) on mineral surfaces.Quantum mechanical calculations were performed on the adsorption of these two anions on relaxed clusters of the well-characterized sulfide galena (PbS) and some other Fe and S-bearing materials. With these calculations, we gain insight into differences between the anions' adsorption behavior, including geometry, adsorption energies, and electronic structure. Differences between interactions on terraces and step edges, the effects of co-adsorbates such as Na+ and Cl-, and chloride complexation are also explored. The influence of water was calculated using homogeneous dielectric fluids.As a complement to the calculations, batch sorption tests are in progress involving ReO4-/TcO4- solution in contact with Fe metal, 10% Fe-doped hydroxyapatite, goethite, hematite, magnetite, pyrite, galena, and sphalerite.

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22

Jain, Suman L., Jomy K. Joseph, and Bir Sain. "Rhenium-Catalyzed Highly Efficient Oxidations of Tertiary Nitrogen Compounds to N-Oxides Using Sodium Percarbonate as Oxygen Source." ChemInform 38, no. 7 (February 13, 2007). http://dx.doi.org/10.1002/chin.200707032.

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23

Meshkov, E. Yu, N. A. Bobyrenko, I. A. Parygin, and A. A. Soloviev. "Trapping nitrous gases during nitric acid leaching of sulfide concentrates." Tsvetnye Metally, February 26, 2021, 29–36. http://dx.doi.org/10.17580/tsm.2021.02.04.

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Gas-air mixtures that form in nitric acid leaching of sulfide raw materials possess the following peculiarities making a negative impact on trapping of nitrogen oxides: elevated temperature, different oxidation level of nitrogen oxides, slow oxidation of NO in region of low concentrations, and instability of the resulting gas-air mixture flow. Therefore, well-known methods of trapping nitrous gases shall be adapted to specific sulfide raw material. We propose a process flow diagram for trapping nitrous gases formed during nitric acid leaching of sulfide concentrates at atmospheric pressure on the example of Zhezkazgan concentrate. The paper addresses theoretical aspects of the use of water-ore pulp, concentrated sulfuric acid, process water and alkaline agents for trapping nitrous gases, and typical reactions of interaction of the proposed absorbents with nitrogen oxides. The choice of water-ore pulp as an absorber was made because of similarity between the mechanism of absorption of nitrogen oxides for neutral and alkali ore suspensions and the one for alkali solutions: nitrogen dioxide and nitrous anhydride are absorbed with formation of a solution of nitrates and nitrites. Due to availability in a liquid phase of ferrous iron along with NO2 and N2O3, acidic suspensions are also capable to absorb nitric oxide, to some extent, with formation of Fe(NO)SО4 complex. Process water absorbs only nitrogen dioxide, with formation of nitric and nitrous acids. Nitrous acid is an unstable compound in acidic environments and decomposes with formation of water and nitrogen oxide. At the stages of trapping nitrogen oxides with water-ore pulp and process water (circulating solution), it is recommended conditioning of gas-air mixtures by choosing the volume of additionally introduced air, in an amount to provide the highest rate of nitrogen oxide oxidation. At the stages of sulfuric acid and alkaline trapping of nitrogen oxides, it is recommended conditioning of gas-air mixtures by selecting the volume of additionally introduced air and the oxidation time of nitrogen oxide that provide an equimolecular mixture of NO and NO2. A distinctive feature of the use of water-ore pulp, concentrated sulfuric acid, process water and alkaline agents for trapping nitrous gases is possibility to use the products of absorption at the stage of sulfide concentrate leaching. The extended tests of trapping nitrous gases have been conducted. The plant capacity by the gas-air mixture ranged 17–21 m3/h, and by leached concentrate — 12–15 kg/h. In this case, the degree of capturing nitrous gases reached 96.8%. Return of the products of absorption of nitrous gases in the form of condensate, water-ore pulp, nitrosyl sulfuric acid, nitric acid solution, nitritenitrate lye allows to reduce the nitric acid consumption by 7–10 times relative the values obtained without using the trapping system. In this case, the degree of copper extraction into the leaching solution was 97.7%. The extraction degree of silver, rhenium, zinc was respectively 98.0%, 99.0%; 98.5%.

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