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