Chromium(VI) oxide peroxide is the name given to a collection of chromium coordination complexes. They have the formula CrO(O2)2L where L is a ligand. These species are dark blue and often labile. They all feature oxoligand and two peroxo ligands, with the remaining coordination sites occupied by water, hydroxide, ether, or other Lewis bases.[1]
Structure of CrO(O2)2(pyridine). Hydrogen atoms bonded to carbon atoms are omitted. Color code: Cr = gray, C= black, H = white, O= red, N = blue.
Chromium(VI) oxide peroxide is formed by the addition of acidified hydrogen peroxide solutions to solutions of metal chromates or dichromates, such as sodium chromate or potassium dichromate. The generally yellow chromates or orange dichromates turn to dark blue as "chromium(VI) oxide peroxide" forms:
CrO2−4 + 2 H2O2 + H+ → [CrO(O2)2OH]− + 3 H2O
The structure of the pyridine complex has been determined crystallographically.[2] Adducts with other N-heterocycles have also been characterized similarly.[3]
Aqueous chromium(VI) oxide peroxide decomposes in a few seconds, turning green as chromium(III) compounds are formed.[4]
Stable adducts of the type CrO(O2)2L include those with L = diethyl ether, 1-butanol, ethyl acetate, or amyl acetate. They form by adding a layer of the organic solvent above the chromate/dichromate solution and shaking during the addition of hydrogen peroxide.
"chromium(VI) oxide peroxide" in ether phase (above) and chromium(III) aqueous solution (below).
See alsoedit
Tetraperoxochromate - an similarly-synthesized analogous chromium(V) peroxide complex
Referencesedit
^Gili, Pedro; Mederos, Alfredo; Lorenzo-Luis, Pablo A.; de la Rosa, Eduardo Medina; Muñoz, Alfonso (2002). "On the interaction of compounds of chromium(VI) with hydrogen peroxide. A study of chromium(VI) and (V) peroxides in the acid–basic pH range". Inorganica Chimica Acta. 331: 16–24. doi:10.1016/S0020-1693(01)00747-2.
^Stomberg, Rolf; Ainalem, Ing-Britt; Johansson, Gunnar; Tolboe, O.; Paasivirta, Jaakko (1968). "The Crystal Structure of two Modifications of Oxidodiperoxido-2,2'-dipyridylchromium(VI), [CrO(O2)2(C10H8N2)]". Acta Chemica Scandinavica. 22: 1439–1451. doi:10.3891/acta.chem.scand.22-1439.
^Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils; (1985). "Chromium" (in German). Lehrbuch der Anorganischen Chemie (91–100 ed.). Walter de Gruyter. pp. 1081–1095. ISBN3-11-007511-3."
^Firouzabadi, H.; Iranpoor, N.; Kiaeezadeh, F.; Toofan, J. (1986). "Chromium(VI) based oxidants-1 Chromium peroxide complexes as versatile, mild, and efficient oxidants in organic synthesis". Tetrahedron. 42: 719. doi:10.1016/S0040-4020(01)87476-7.
chromium, oxide, peroxide, name, given, collection, chromium, coordination, complexes, they, have, formula, where, ligand, these, species, dark, blue, often, labile, they, feature, ligand, peroxo, ligands, with, remaining, coordination, sites, occupied, water,. Chromium VI oxide peroxide is the name given to a collection of chromium coordination complexes They have the formula CrO O2 2L where L is a ligand These species are dark blue and often labile They all feature oxo ligand and two peroxo ligands with the remaining coordination sites occupied by water hydroxide ether or other Lewis bases 1 Chromium VI oxide peroxide Names IUPAC name Chromium VI oxide diperoxide Other names Chromium VI oxide peroxideChromium pentoxide chromium oxide peroxide chromium VI oxide diperoxide Identifiers CAS Number 35262 77 2 applies to CrO5 which exists only as adducts see image N 3D model JSmol Interactive image PubChem CID 22222816 CompTox Dashboard EPA DTXSID201029514 InChI InChI 1 Cr 5O q 2 2 1 rCrO4 O c2 1 3 4 5 q2 2Key ZWPVWTIRZYDPKW NIUFNKCUAY SMILES O0O Cr 01 O OO1 Properties Chemical formula CrO O2 2 Molar mass 131 991 g mol 1 Appearance Dark blue Solubility in water soluble decomposes without stabilisers Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Preparation and properties 2 Gallery 3 See also 4 References 5 External linksPreparation and properties edit nbsp Structure of CrO O2 2 pyridine Hydrogen atoms bonded to carbon atoms are omitted Color code Cr gray C black H white O red N blue Chromium VI oxide peroxide is formed by the addition of acidified hydrogen peroxide solutions to solutions of metal chromates or dichromates such as sodium chromate or potassium dichromate The generally yellow chromates or orange dichromates turn to dark blue as chromium VI oxide peroxide forms CrO2 4 2 H2O2 H CrO O2 2OH 3 H2O The structure of the pyridine complex has been determined crystallographically 2 Adducts with other N heterocycles have also been characterized similarly 3 Aqueous chromium VI oxide peroxide decomposes in a few seconds turning green as chromium III compounds are formed 4 2 CrO O2 2 7 H2O2 6 H 2 Cr3 10 H2O 7 O2 Stable adducts of the type CrO O2 2L include those with L diethyl ether 1 butanol ethyl acetate or amyl acetate They form by adding a layer of the organic solvent above the chromate dichromate solution and shaking during the addition of hydrogen peroxide The etherate bis pyridine and pyridine complexes of this compound have been found to be effective oxidants in organic chemistry 5 Gallery edit nbsp An aqueous solution of chromium peroxide nbsp A dilute solution of chromium peroxide nbsp chromium VI oxide peroxide in ether phase above and chromium III aqueous solution below See also editTetraperoxochromate an similarly synthesized analogous chromium V peroxide complexReferences edit Gili Pedro Mederos Alfredo Lorenzo Luis Pablo A de la Rosa Eduardo Medina Munoz Alfonso 2002 On the interaction of compounds of chromium VI with hydrogen peroxide A study of chromium VI and V peroxides in the acid basic pH range Inorganica Chimica Acta 331 16 24 doi 10 1016 S0020 1693 01 00747 2 Stomberg Rolf 1962 Crystal Structure of Peroxochromates CrO5 C5H5N Nature 196 4854 570 571 doi 10 1038 196570b0 S2CID 4187294 Stomberg Rolf Ainalem Ing Britt Johansson Gunnar Tolboe O Paasivirta Jaakko 1968 The Crystal Structure of two Modifications of Oxidodiperoxido 2 2 dipyridylchromium VI CrO O2 2 C10H8N2 Acta Chemica Scandinavica 22 1439 1451 doi 10 3891 acta chem scand 22 1439 Holleman Arnold F Wiberg Egon Wiberg Nils 1985 Chromium in German Lehrbuch der Anorganischen Chemie 91 100 ed Walter de Gruyter pp 1081 1095 ISBN 3 11 007511 3 Firouzabadi H Iranpoor N Kiaeezadeh F Toofan J 1986 Chromium VI based oxidants 1 Chromium peroxide complexes as versatile mild and efficient oxidants in organic synthesis Tetrahedron 42 719 doi 10 1016 S0040 4020 01 87476 7 External links editExperimental details and photo in German Losing fingers to chemistry on YouTube 8 November 2012 Professor Martyn Poliakoff of the University of Nottingham demonstrates the synthesis on Periodic Videos Retrieved from https en wikipedia org w index php title Chromium VI oxide peroxide amp oldid 1223537825, wikipedia, wiki, book, books, library,
