View source for Iodoform


{{Chembox new
| ImageFileL1 = Iodoform-2D-skeletal.png
| ImageSizeL1 = 80px
| ImageFileR1 = Iodoform-3D-vdW.png
| ImageSizeR1 = 120px
| IUPACName = Iodoform
| OtherNames = Triiodomethane, Methyl triiodide, Carbon triiodide, TIM
| Section1 = {{Chembox Identifiers
|   CASNo = 75-47-8
|   EINECS = 200-874-5
|   PubChem = 6374
|   SMILES = C(I)(I)I
|   InChI = 1/CHI3/c2-1(3)4/h1H
|   RTECS = PB7000000
|   ChEBI = 37758
|   KEGG = D01910
  }}
| Section2 = {{Chembox Properties
|   Formula = CHI<sub>3</sub>
|   MolarMass = 393.73 g/mol
|   Appearance = Yellowish crystalls
|   Density = 4.008 g/cm<sup>3</sup>
|   MeltingPt = 123 °C
|   BoilingPt = 217 °C (expl.)
|   Solubility = 0.1 g/l at 20 °C
|   LogP = 3.83
|   HenryConstant = 0.34 mol.kg<sup>-1</sup>.bar<sup>-1</sup>
  }}
| Section3 = {{Chembox Structure
|   CrystalStruct = Hexagonal
|   Coordination = 
|   MolShape = Tetrahedral
  }}
| Section4 = {{Chembox Hazards
|   EUClass = Harmful ('''Xn'''), Dangerous for the environment ('''N''')
|   MainHazards = 
|   RPhrases = {{R20/21/22}}, {{R36/37/38}}
|   SPhrases = {{S22}}, {{S26}}, {{S36/37/39}}
|   NFPA-H = 2
|   NFPA-F = 0
|   NFPA-R = 1
|   NFPA-O = 
|   FlashPt = 204 °C
|   Autoignition = 
  }}
}}

{{SI}}

==Overview==
The compound '''iodoform''' is [[Carbon|C]][[Hydrogen|H]][[Iodine|I]]<sub>3</sub>. A pale yellow, crystalline, volatile substance, it has a penetrating odor (in older chemistry texts, the smell is sometimes referred to as the smell of hospitals) and, analogous to [[chloroform]], sweetish taste. It is slightly soluble in [[glycerol]], [[petroleum ether]] or [[alcohol]] (78 g/l at 25 °C), averagely soluble in chloroform, [[acetic acid]] and [[Diethyl ether|ether]] (136 g/l at 25 °C) and easily soluble in [[benzene]] and [[acetone]] (120 g/l at 25 °C).

== Physical properties ==
Its entalphy of sublimation is 69.9 kJ.mol<sup>-1</sup> at range of temperatures 35 - 92 °C. 

Iodoform molecule parameters are: d(C-I) = 2.12 ± 0.04 Å, d(I-I) = 3.535 ± 0.01 Å and I-C-I = 113°. Dipole moment is 1 D. Its space group is ''P6<sub>3</sub>'' and [[lattice constant]]s are ''a'' = 6.83 Å, ''c'' = 7.52 Å.

It has critical point at 584.85 °C, 5.63 MPa. Refractive index is 1.786 (D, 20 °C).

== Synthesis ==
It was first prepared by Georges Serrulas in 1822 and its molecular formula was identified by [[Jean-Baptiste Dumas]] in 1834.

Iodoform can be synthesized in the [[haloform reaction]] by the reaction of iodine and sodium hydroxide with any one of these four kinds of organic compounds:
* a methyl [[ketone]]: CH<sub>3</sub>COR, where R is an organic [[side chain]].
* [[acetaldehyde]]: CH<sub>3</sub>CHO
* [[ethanol]]: CH<sub>3</sub>CH<sub>2</sub>OH
* secondary [[alcohol]]s: CH<sub>3</sub>CHROH, where R is an alkyl or aryl group.

[[Image:Iodoform synthesis.png]]

These reactions are so reliable that it is called the iodoform test, signalled by the precipitation of pale yellow crystals.

== Reactions ==
Some reagents (e.g. [[hydroiodic acid]]) can convert iodoform to [[diiodomethane]].

Also conversion to [[carbon dioxide]] is possible. Iodoform reacts with [[silver nitrate]] producing [[carbon monoxide]], which is oxidized by mixture of [[sulfuric acid]] and iodine pentaoxide.

== Uses ==
It was used in medicine as a healing and antiseptic dressing for wounds and sores around the beginning of the 20th century, though this use is now superseded by better [[antiseptic]]s.

==References==
*''Merck Index'', 12 Edition, '''5054'''.

== See also ==
* [[Haloalkane]]
* [[Halomethane]]
* [[Trihalomethane]]
* [[Iodomethane]]
* [[Diiodomethane]]
* [[Carbon tetraiodide]] (Tetraiodomethane)
* [[Fluoroform]]
* [[Chloroform]]
* [[Bromoform]]
* Iodoform reaction

== External links ==
*{{PGCH|0343}}
*[http://ptcl.chem.ox.ac.uk/MSDS/IO/iodoform.html MSDS at Oxford University]
*[http://www.sciencelab.com/xMSDS-Iodoform-9924389 MSDS at Science Lab]
*[http://pubs.acs.org/cgi-bin/abstract.cgi/jacsat/1952/74/i09/f-pdf/f_ja01129a067.pdf?sessid=6006l3 A Method for the Specific Conversion of Iodoform to Carbon Dioxide]
*[http://www.1911encyclopedia.org/Iodoform Article at 1911 Encyclopaedia Britannica]
*[http://www.creative-chemistry.org.uk/alevel/module3/documents/N-ch3-16.pdf Preparation]

{{Medicated dressings}}


[[Category:Organoiodides]]
[[Category:Halomethanes]]
[[Category:Antiseptics]]


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[[ru:Иодоформ]]
[[tr:İyodoform]]
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