Cobalt(III) hydroxide

Cobalt(III) hydroxide
Names
	IUPAC name Cobalt(III) hydroxide
	Other names Cobaltic hydroxide
Identifiers
CAS Number	1307-86-4 ;
3D model (JSmol)	Interactive image;
ChemSpider	8278661 ;
ECHA InfoCard	100.013.776
EC Number	215-153-0;
PubChem CID	10103133;
UNII	S42YMM16W7;
CompTox Dashboard (EPA)	DTXSID50926862 ;
	InChI InChI=1S/Co.3H2O/h;3*1H2/q 3;;;/p-3 [pubchem] Key: FXVNMSSSMOVRTC-UHFFFAOYSA-K [pubchem];
	SMILES [OH-].[OH-].[OH-].[Co 3];
Properties
Chemical formula	Co(OH)3
Molar mass	109.95522 g
Appearance	brown-black or dark green powder
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H319, H334, H413
Precautionary statements	P261, P264, P273, P280, P285, P304 P341, P305 P351 P338, P337 P313, P342 P311, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Cobalt(III) hydroxide or cobaltic hydroxide is a chemical compound with formula Co(OH)
₃ or H
₃CoO
₃. It is an ionic compound, with trivalent cobalt cations Co³
and hydroxyl anions OH⁻
.

The compound is known in two structurally different forms, "brownish-black" and "green". The brownish-black form is a stable solid and can be prepared by reaction of water solutions of cobalt(II) chloride and sodium hydroxide, followed by oxidation with ozone.^[1]

The green form, formerly thought to be cobalt(II) peroxide, apparently requires carbon dioxide as a catalyst. It can be prepared by adding hydrogen peroxide to a solution of cobalt(II) chloride in 96% ethanol at –30 to –35°C, then adding a 15% solution of sodium carbonate in water with intense stirring. The resulting dark green powder is fairly stable at liquid nitrogen temperature, but at room temperature it turns dark brown within a few days.^[2]

Natural occurrence

As of 2020, Cobalt(III) hydroxide is unknown among the known mineral species. However, heterogenite, CoO(OH), is known.^[3]^[4]

References

^ Pankratov, D.A., Veligzhanin, A.A., and Zubavichus, Y.V. (2013): "Structural Features of Green Cobalt(III) Hydroxide". Russian Journal of Inorganic Chemistry, volume 58, issue 1, pages 67–73. doi:10.1134/S0036023613010142
^ Pankratov, D.A., Portachenko, T.A., and Perfil’ev, Y.D. (2008): "Emission Mössbauer Study of 'Cobalt Peroxide'". Moscow University Chemical Bulletin, volume 63, issue 5, pages 292–296. doi:10.3103/S002713140805012X
^ "Heterogenite".
^ "List of Minerals". 21 March 2011.

[pank1-1] Pankratov, D.A., Veligzhanin, A.A., and Zubavichus, Y.V. (2013): "Structural Features of Green Cobalt(III) Hydroxide". Russian Journal of Inorganic Chemistry, volume 58, issue 1, pages 67–73. doi:10.1134/S0036023613010142

[pank2-2] Pankratov, D.A., Portachenko, T.A., and Perfil’ev, Y.D. (2008): "Emission Mössbauer Study of 'Cobalt Peroxide'". Moscow University Chemical Bulletin, volume 63, issue 5, pages 292–296. doi:10.3103/S002713140805012X

[3] "Heterogenite".

[4] "List of Minerals". 21 March 2011.

[1]

[2]

[3]

[4]

Cobalt(III) hydroxide

Natural occurrence

See also

References