Cobalt(II) iodide

Names
IUPAC name

Cobalt(II) iodide

Other names

cobaltous iodide, cobalt diiodide

Identifiers

CAS Number

* 15238-00-3 (HCl) Y
* 52595-03-6 (hexahydrate) N

3D model (JSmol)

* Interactive image

ChemSpider |

* 76542 N

EC Number |

* 239-283-2

PubChem CID

* 419951

UNII |

* RTJ1W9DF34 Y

InChI

* InChI=1S/Co.2HI/h;2*1H/q+2;;/p-2 N

Key: AVWLPUQJODERGA-UHFFFAOYSA-L N

* InChI=1/Co.2HI/h;2*1H/q+2;;/p-2

Key: AVWLPUQJODERGA-NUQVWONBAD

SMILES

* [Co+2].[I-].[I-]

Properties

Chemical formula

| CoI2
Molar mass | 312.7421 g/mol (anhydrous)
420.83 g/mol (hexahydrate)
Appearance  | α-form: black hexagonal crystal
β-form: yellow powder
Density | α-form: 5.584 g/cm3
β-form: 5.45 g/cm3
hexahydrate: 2.79 g/cm3
Melting point | α-form: 515-520 °C under vacuum
β-form: converts to α-form at 400 °C
Boiling point |  570 °C (1,058 °F; 843 K)

Solubility in water

| 67.0 g/100 mL[1]

Magnetic susceptibility (χ)

| +10,760·10−6 cm3/mol
Hazards
GHS pictograms |
GHS Signal word | Warning

GHS hazard statements

| H302, H312, H315, H319, H332, H335
NFPA 704 (fire diamond)  |

Related compounds

Other anions

| Cobalt(II) fluoride
Cobalt(II) chloride
Cobalt(II) bromide

Other cations

| Nickel(II) iodide
Copper(I) iodide

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

N verify (what is YN ?)
Infobox references

Cobalt(II) iodide or cobaltous iodide are the inorganic compounds with the formula CoI2 and the hexahydrate CoI2(H2O)6. These salts are the principal iodides of cobalt.[2]

## Contents

* 1 Synthesis
* 2 Structures
* 3 Reactions and applications
* 4 References

## Synthesis

Cobalt(II) iodide is prepared by treating cobalt powder with gaseous hydrogen iodide.[2] The hydrated form CoI2.6H2O can be prepared by the reaction of cobalt(II) oxide (or related cobalt compounds) with hydroiodic acid.

Cobalt(II) iodide crystallizes in two polymorphs, the α- and β-forms. The α-polymorph consists of black hexagonal crystals, which turn dark green when exposed to air. Under a vacuum at 500 °C, samples of α-CoI2 sublime, yielding the β-polymorph as a yellow crystals. β-CoI2 also readily absorbs moisture from the air, converting into green hydrate. At 400 °C, β-CoI2 reverts to the α-form.[2]

## Structures

The anhydrous salts adopt the cadmium halide structures.

The hexaaquo salt consists of separated [Co(H2O)6]2+ and iodide ions as verified crystallographically.[3][4]

## Reactions and applications

Anhydrous cobalt(II) iodide is sometimes used to test for the presence of water in various solvents.[5]

Cobalt(II) iodide is used as a catalyst, e.g. in carbonylations. It catalyzes the reaction of diketene with Grignard reagents, useful for the synthesis of terpenoids[6]

## References

1. ↑ Perry, Dale L.; Phillips, Sidney L. (1995), Handbook of Inorganic Compounds, CRC Press, pp. 127–8, ISBN 0-8493-8671-3, https://books.google.com/books?id=0fT4wfhF1AsC&q="Cobalt(II)+iodide"&pg=PA128, retrieved 2008-06-03
2. ↑ 2.0 2.1 2.2 O. Glemser "Cobalt, Nickel" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1518.
3. ↑ “Structure Cristalline et Expansion Thermique de L’Iodure de Nickel Hexahydrate“ (Crystal structure and thermal expansion of nickel(II) iodide hexahydrate) Louër, Michele; Grandjean, Daniel; Weigel, Dominique Journal of Solid State Chemistry (1973), 7(2), 222-8. doi: 10.1016/0022-4596(73)90157-6
4. ↑ "The crystal structure of the crystalline hydrates of transition metal salts. The structure of CoI2·6H2O" Shchukarev, S. A.; Stroganov, E. V.; Andreev, S. N.; Purvinskii, O. F. Zhurnal Strukturnoi Khimii 1963, vol. 4, pp. 63-6.<!no doi in CAS-->
5. ↑ Armarego, Wilfred L. F.; Chai, Christina L. L. (2003), Purification of Laboratory Chemicals, Butterworth-Heinemann, pp. 26, ISBN 0-7506-7571-3, https://books.google.com/books?id=SYzm1tx2z3QC&q="Cobalt(II)+iodide"&pg=PA26, retrieved 2008-06-03
6. ↑ Agreda, V. H.; Zoeller, Joseph R. (1992), Acetic Acid and Its Derivatives, CRC Press, pp. 74, ISBN 0-8247-8792-7, https://books.google.com/books?id=3MjdGp1v1YIC&q="Cobalt(II)+iodide"&pg=RA1-PA784, retrieved 2008-06-03

* v
* t
* e

Cobalt compounds

* CoBr2
* Co(CN)2
* CoCO3
* CoC2O4
* CoCl2
* CoCl3
* Co(ClO3)2
* CoF2
* CoF3
* CoI2
* Co(NO3)2
* Co(NO3)3
* CoO
* Co(OH)2
* CoS
* CoSO4
* CoSe
* Co2O3
* Co2P
* Co3O4
* Co3(PO4)2
* Co(Ac)2

HI |  |  |  | He

|
|
|
|

LiI | BeI2 | BI3 | CI4 | NI3 | I2O4,
I2O5,
I4O9 | IF,
IF3,
IF5,
IF7 | Ne
NaI | MgI2 | AlI3 | SiI4 | PI3,
P2I4 | S  | ICl,
ICl3 | Ar
KI | CaI2 | Sc  | TiI4 | VI3 | CrI3 | MnI2 | FeI2 | CoI2 | NiI2 | CuI | ZnI2 | Ga2I6 | GeI2,
GeI4 | AsI3 | Se  | IBr | Kr
RbI | SrI2 | YI3 | ZrI4 | NbI5 | Mo  | Tc  | Ru  | Rh  | Pd  | AgI | CdI2 | InI3 | SnI4,
SnI2 | SbI3 | TeI4 | I  | Xe
CsI | BaI2 |  | HfI4 | TaI5 | W  | Re  | Os  | Ir  | Pt  | AuI | Hg2I2,
HgI2 | TlI | PbI2 | BiI3 | Po  | AtI | Rn
Fr  | RaI2 |  | Rf  | Db  | Sg  | Bh  | Hs  | Mt  | Ds  | Rg  | Cn  | Nh  | Fl  | Mc  | Lv  | Ts  | Og
| ↓  |  |
La  | Ce  | Pr  | Nd  | Pm  | SmI2 | Eu  | Gd  | TbI3 | Dy  | Ho  | Er  | Tm  | Yb  | Lu
Ac  | ThI4 | Pa  | UI3,
UI4 | Np  | Pu  | Am  | Cm  | Bk  | Cf  | EsI3 | Fm  | Md  | No  | Lr

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Cobalt(II) iodide. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Chemistry:Cobalt(II)_iodide&oldid=2598947"
*[CID]: Compound ID
*[H302]: Harmful if swallowed
*[H312]: Harmful in contact with skin
*[H315]: Causes skin irritation
*[H319]: Causes serious eye irritation
*[H332]: Harmful if inhaled
*[H335]: May cause respiratory irritation
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template