Dicobalt edetate

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Dicobalt edetate
Dicobalt edetate.png
Dicobalt edetate 3D ball.png
Names
Other names
Kelocyanor
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.048.227 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C10H16N2O8.2Co/c13-7(14)3-11(4-8(15)16)1-2-12(5-9(17)18)6-10(19)20;;/h1-6H2,(H,13,14)(H,15,16)(H,17,18)(H,19,20);;/q;2*+2/p-4 Yes check.svgY
    Key: TWAWHTJKASJPEK-UHFFFAOYSA-J Yes check.svgY
  • InChI=1/C10H16N2O8.2Co/c13-7(14)3-11(4-8(15)16)1-2-12(5-9(17)18)6-10(19)20;;/h1-6H2,(H,13,14)(H,15,16)(H,17,18)(H,19,20);;/q;2*+2/p-4
    Key: TWAWHTJKASJPEK-XBHQNQODAQ
  • C(CN(CC(=O)[O-])CC(=O)[O-])N(CC(=O)[O-])CC(=O)[O-].[Co+2].[Co+2]
  • [Co+2].[Co+2].[O-]C(=O)CN(CC([O-])=O)CCN(CC([O-])=O)CC([O-])=O
Properties
C10H12Co2N2O8.6H2O
Molar mass 406.08 g/mol
514.18 g/mol (hexahydrate)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Dicobalt edetate is the coordination compound with the approximate formula Co2(EDTA)(H2O)6. It is a derivative of the (non-natural) amino acid ethylenediaminetetraacetate.

Contents

Solutions of this solid have been used in Europe as an antidote to cyanide poisoning, with the trade name Kelocyanor. [1] However, dicobalt edetate is itself toxic, particularly if there is not enough cyanide in the blood to react with it, so it is only suitable for serious cases of poisoning. In the past, workplaces in the UK that handle cyanide were recommended to keep a 'Kelocyanor kit', to be taken to the hospital along with the patient, but this practice has been discontinued since it may mislead doctors into using the antidote unnecessarily. [2]

Structure

The compound is polymeric in the crystalline form. Half of the Co2+ ions are bound to the EDTA2 and the other Co2+ ions are bound to four water ligands as well as carboxylate ligands on the [Co(EDTA)]2 entity. [3] In aqueous solution, depolymerization occurs to give [Co(EDTA)]2 and [Co(H2O)6]2+ ions, each of which is kinetically labile and has a high affinity for cyanide.

Oxidation of [Co(II)(EDTA)]2 gives [Co(III)(EDTA)], which is so kinetically inert that it can be resolved optically. [4]

Related Research Articles

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Ethylenediaminetetraacetic acid Chemical compound

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2
. The compound forms several hydrates CoCl
2
nH
2
O
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References

  1. Pickering WG (December 1985). "Cyanide toxicity and the hazards of dicobalt edetate". Br Med J (Clin Res Ed). 291 (6509): 1644. doi:10.1136/bmj.291.6509.1644-a. PMC   1418389 . PMID   2866807.
  2. "Cyanide poisoning – New recommendations on first aid treatment". Health and Safety Executive. Archived from the original on 20 October 2009.
  3. E. F. K. Mccandlish, T. K. Michael; Rose, N. J.; Neal, J. A.; Lingafelter, E. C.; Rose, N. J. (1978). "Comparison of the Structures and Aqueous Solutions of [(O-Phenylenediaminetetraacetato(2-)]Cobalt(II) and [Ethylenediaminetetraacetato(2-)]Cobalt(II)". Inorg. Chem. 17 (6): 1383–94. doi:10.1021/ic50184a001.
  4. Dwyer, F. P.; Garvan, F. L. (1960). Resolution of the Ethylenediaminetetracetatocobaltate(III) Ion. Inorg. Synth. Inorganic Syntheses. Vol. VI. pp. 192–4. doi:10.1002/9780470132371.ch61. ISBN   978-0-470-13237-1.