Copper peroxide
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| IUPAC name
Copper(II) peroxide
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
CompTox Dashboard (EPA)
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| Properties | |
| Cu(O2) | |
| Molar mass | 95.945 g/mol |
| Appearance | Various |
| Related compounds | |
Related compounds
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Copper(IV) oxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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Copper peroxide is an inorganic compound with the chemical formula Cu(O2). The 1:2 ratio of copper and oxygen would be consistent with copper in its common +2 oxidation state and a peroxide group. Cu(O2) has attracted interest from a computational perspective. One highly cited analysis concludes that gaseous Cu(O2) is a superoxide, with copper in a +1 oxidation state: Cu+O−2.[1]
Older literature claims that treatment of cold suspended Cu(OH)2 with H2O2 creates a brown hydrate of "copper dioxide," which rapidly decomposes in the presence of water to form ill-defined green and yellow salts above 0 °C.[2]
History
Species claimed to be "copper peroxide" have been claimed, e.g., by the reaction of cold solutions of Schweizer's reagent—a source of copper(II)—and hydrogen peroxide.[3] The Schweizer's reagent used must not contain excess ammonia.[3]
It was once claimed to result from the very slow reaction of finely divided cupric oxide with cold hydrogen peroxide.[4]
It has been claimed that brown "copper dioxide" synthesized from Cu(OH)2 can be dried above 100 °C without decomposition if the product is thoroughly rid of moisture via alcohol washings.[2] The resulting product is claimed to be a copper peroxide hydrate.
Several well-characterized molecular copper peroxide complexes have been reported, but these species always feature supporting organic ligands.[5]
Structure
Several substances claimed to be inorganic copper(II) peroxides have been reported,[6][7]: 22–23 with empirical formulae:
- Cu(O2)·H2O, a dark brown solid prepared by the reaction of freshly-made (blue) Cu(OH)2 with moderate-concentration solutions of H2O2 between −20 °C and 20 °C.[6][8][9] An alternative route is the reaction of an ethanol–water solution of CuCl2 with H2O2, followed by ethanolic KOH, at −40 to −50 °C.[6] Possible structures include Cu(OH)(OOH) (mixed hydroxide-hydroperoxide) and Cu(O2)·H2O (hydrate).[6] Electron spin resonance measurements indicate it does not contain CuO.[10] An early publication claims it turns olive-green with age, as well as upon reaction with excess peroxide.[11]
- Cu(O2)·H2O2·H2O, prepared by the reaction of freshly-made Cu(OH)2 with concentrated solutions of hydrogen peroxide between −36 °C and 20 °C.[6][8] A possible structure is the perhydrate Cu(OH)(OOH)·H2O2.[12]
- Cu2(O2)(OOH), an olive-green solid claimed to be obtainable at −79 °C.[6]
References
- ^ Gutsev, G. L.; Rao, B. K.; Jena, P. (2000). "Systematic Study of Oxo, Peroxo, and Superoxo Isomers of 3d-Metal Dioxides and Their Anions". The Journal of Physical Chemistry A. 104 (51): 11961–11971. Bibcode:2000JPCA..10411961G. doi:10.1021/jp002252s.
- ^ a b Osborne, T. B. (1886). The higher oxides of copper. American Journal of Science, s3-32(191), 333–342. https://doi.org/10.2475/ajs.s3-32.191.333
- ^ a b The Collected Works of Sir Humphry Davy: Discourses delivered before the Royal society. Elements of agricultural chemistry, pt. I. The Chemical Society (Great Britain). 1894. p. 32.
- ^ Krüss, Gerhard (November 1884). "Einige Beobachtungen über die höheren Sauerstoffverbindungen des Kupfers" [Some observations on the higher oxides of copper] (abstract). Berichte der deutschen chemischen Gesellschaft (in German). 17 (2): 2593–2597. doi:10.1002/cber.188401702186.
- ^ Elwell, Courtney E.; Gagnon, Nicole L.; Neisen, Benjamin D.; Dhar, Debanjan; Spaeth, Andrew D.; Yee, Gereon M.; Tolman, William B. (2017). "Copper–Oxygen Complexes Revisited: Structures, Spectroscopy, and Reactivity". Chemical Reviews. 117 (3): 2059–2107. doi:10.1021/acs.chemrev.6b00636. PMC 5963733. PMID 28103018.
- ^ a b c d e f Connor, J.A.; Ebsworth, E.A.V. (1964). "Peroxy Compounds of Transition Metals". Advances in Inorganic Chemistry and Radiochemistry. 6: 279–381. doi:10.1016/S0065-2792(08)60229-0.
- ^ Vol’nov, Il’ya Ivanovich (1966) [1964]. "Peroxides of the Group One Metals of the Periodic Table". In Petrocelli, A. W. (ed.). Peroxides, Superoxides, and Ozonides of Alkali and Alkaline Earth Metals. Translated by Woroncow, J. New York, NY: Springer. pp. 21–55. doi:10.1007/978-1-4684-8252-2_3. ISBN 978-1-4684-8252-2.
- ^ a b Makarov, S. Z.; Arnol'd, T. I.; Stasevich, N. N.; Shorina, E. V. (November 1960). "An investigation of systems containing concentrated hydrogen peroxide: Communication XXI. The ternary system Cu(OH)2-H2O2-H2O". Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 9 (11): 1789–1795. doi:10.1007/BF00907733.
- ^ Moser, Ludwig [at Wikidata] (27 March 1914). "Über das Kupferperoxyt" [On Copper Peroxide]. Zeitschrift für anorganische Chemie (in German). 86 (1): 380–388. doi:10.1002/zaac.19140860128.
- ^ Vierke, Gerhard (1973). "Electron spin resonance spectra of the reaction products of copper(II) hydroxide suspensions in methanol with hydrogen peroxide and of polycrystalline copper(II) hydroxide and copper(II) peroxide". Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases. 69 (0): 1523. doi:10.1039/F19736901523.
- ^ Robertson, Alfred Crawford (May 1925). "Promoter Action in Homogeneous Catalysis. II Mechanism of the Promotion by Copper Salts in the Catalytic Decomposition of Hydrogen Peroxide by Ferric Salts". Journal of the American Chemical Society. 47 (5): 1299–1314. doi:10.1021/ja01682a013.
- ^ Makarov, S. Z.; Arnol'd, T. I.; Stasevich, N. N.; Shorina, E. V. (December 1960). "Systems with concentrated hydrogen peroxide: Communication XXII. Thermal analysis of copper peroxides". Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 9 (12): 1940–1944. doi:10.1007/BF00912042.