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| ImageFile1 = Cadmium-iodide-3D-octahedra.png
| ImageFile1 = Cadmium-iodide-3D-octahedra.png
| ImageName1 = Cadmium iodide
| ImageName1 = Cadmium iodide
| ImageFile2 = Cadmium iodide-structure.png
| IUPACName = Cadmium(II) iodide
| IUPACName = Cadmium(II) iodide
| OtherNames = Cadmium diiodide
| OtherNames = Cadmium diiodide
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===Chalcogenides of M<sup>4+</sup>===
===Chalcogenides of M<sup>4+</sup>===


[[titanium disulfide|TiS<sub>2</sub>]], [[zirconium(IV) sulfide|ZrS<sub>2</sub>]], [[tin(IV) sulfide|SnS<sub>2</sub>]], [[tantalum(IV) sulfide|''α''-TaS<sub>2</sub>]], [[platinum(IV) sulfide|PtS<sub>2</sub>]];
[[titanium(IV) sulfide|TiS<sub>2</sub>]], [[zirconium(IV) sulfide|ZrS<sub>2</sub>]], [[tin(IV) sulfide|SnS<sub>2</sub>]], [[tantalum(IV) sulfide|''α''-TaS<sub>2</sub>]], [[platinum(IV) sulfide|PtS<sub>2</sub>]];


[[titanium(IV) selenide|TiSe<sub>2</sub>]], [[zirconium(IV) selenide|ZrSe<sub>2</sub>]], [[tin(IV) selenide|SnSe<sub>2</sub>]], [[platinum(IV) selenide|PtSe<sub>2</sub>]];
[[titanium(IV) selenide|TiSe<sub>2</sub>]], [[zirconium(IV) selenide|ZrSe<sub>2</sub>]], [[tin(IV) selenide|SnSe<sub>2</sub>]], [[platinum(IV) selenide|PtSe<sub>2</sub>]];

Revision as of 12:48, 18 June 2012

Cadmium iodide
Cadmium iodide
Cadmium iodide
Names
IUPAC name
Cadmium(II) iodide
Other names
Cadmium diiodide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.294 Edit this at Wikidata
EC Number
  • 232-223-6
UNII
  • InChI=1S/Cd.2HI/h;2*1H/q+2;;/p-2 checkY
    Key: OKIIEJOIXGHUKX-UHFFFAOYSA-L checkY
  • InChI=1/Cd.2HI/h;2*1H/q+2;;/p-2
    Key: OKIIEJOIXGHUKX-NUQVWONBAZ
  • [Cd+2].[I-].[I-]
Properties
CdI2
Molar mass 366.22 g/mol
Appearance white to pale yellow crystals
Density 5.640 g/cm3, solid
Melting point 387 °C (729 °F; 660 K)
Boiling point 742 °C (1,368 °F; 1,015 K)
787 g/L (0 °C)
847 g/L (20 °C)
1250 g/L (100 °C)
Solubility soluble in ethanol, acetone, ether and ammonia
Structure
Trigonal, hP3, space group P3m1, No. 164
octahedral
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
0
0
Related compounds
Other anions
cadmium fluoride
cadmium chloride
cadmium bromide
Other cations
zinc iodide
mercury(II) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Cadmium iodide, CdI2, is a chemical compound of cadmium and iodine. It is notable for its crystal structure, which is typical for compounds of the form MX2 with strong polarization effects.

Uses

Cadmium iodide is used in lithography, photography, electroplating and the manufacturing of phosphors.[1]

Preparation

Cadmium iodide is prepared by the addition of cadmium metal, or its oxide, hydroxide or carbonate to hydroiodic acid.

Also, the compound can be made by heating cadmium with iodine.

Crystal structure

In cadmium iodide the iodide anions form a hexagonal close packed arrangement while the cadmium cations fill all of the octahedral sites in alternate layers. The resultant structure consists of a layered lattice. This same basic structure is found in many other salts and minerals. Cadmium iodide is mostly ionically bonded but with partial covalent character.[2]

Cadmium iodide's crystal structure is the prototype on which the crystal structures many other compounds can be considered to be based. Compounds with any of the following characteristics tend to adopt the CdI2 structure:

Compounds with the CdI2 crystal structure

The iodide anions in CdI2 form a hexagonal close-packed lattice, while the cadmium cations occupy all of the octahedral holes in alternating layers.

Iodides

MgI2, TiI2, VI2, MnI2, FeI2, CoI2, CaI2, PdI2, PbI2.

Chlorides and bromides

TiCl2, VCl2;

MgBr2, TiBr2, VBr2, MnBr2, FeBr2, CoBr2.

Hydroxides of M2+

Mg(OH)2, Ni(OH)2, Ca(OH)2.

Chalcogenides of M4+

TiS2, ZrS2, SnS2, α-TaS2, PtS2;

TiSe2, ZrSe2, SnSe2, PtSe2;

SiTe2, TiTe2, CoTe2, NiTe2, PdTe2, PtTe2.

Others

AgF2, W2C.

References

  1. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  2. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 1211–1212. ISBN 978-0-08-037941-8.