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for use of the term "iodoform" in cryptography, see Group key

Iodoform is the organoiodine compound with the formula CHI₃. 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 occasionally used as a disinfectant. It is also known as tri-iodomethane, carbon triiodide, and methyl triiodide.

Synthesis and reactions

The synthesis of Iodoform was first described by Georges Serrulas in 1822, by reactions of iodine vapour with steam over red hot coals, and also by reaction of potassium with ethanolic iodine in the presence of water;^[4] and at much the same time independently by John Thomas Cooper.^[5] It is synthesized in the haloform reaction by the reaction of iodine and sodium hydroxide with any one of these four kinds of organic compounds: (i) a methyl ketone: CH₃COR, acetaldehyde (CH₃CHO), ethanol (CH₃CH₂OH), and certain secondary alcohols (CH₃CHROH, where R is an alkyl or aryl group).

The reaction of iodine and base with methyl ketones is so reliable that the "iodoform test" (the appearance of a yellow precipitate) is used to probe the presence of a methyl ketone. This is also the case when testing for secondary alcohols (methyl alcohols).

Some reagents (e.g. hydrogen iodide) convert iodoform to diiodomethane. Also conversion to carbon dioxide is possible: Iodoform reacts with aqueous silver nitrate to produce carbon monoxide. When treated with powdered elemental silver the iodoform is reduced, producing acetylene. Upon heating iodoform decomposes to produce diatomic iodine, hydrogen iodide gas, and carbon.

Natural occurrence

Angel's bonnets contain iodoform and show its characteristic odor.

Applications

The compound finds small scale use as a disinfectant.^[3]^[6] Around the beginning of the 20th century it was used in medicine as a healing and antiseptic dressing for wounds and sores, although this use is now superseded by superior antiseptics. Adolf Hitler's mother, Klara Hitler, died of iodoform poisoning brought on by her treatment for breast cancer. It is the active ingredient in many ear powders for dogs and cats, along with zinc oxide and propanoic acid, which are used to prevent infection and facilitate removal of ear hair.^{[citation needed]}

References

^ ^a ^b ^c ^d ^e ^f ^g Record in the GESTIS Substance Database of the IFA
^ ^a ^b ^c "NIOSH Pocket Guide to Chemical Hazards #0343". National Institute for Occupational Safety and Health (NIOSH).
^ ^a ^b Merck Index, 12 Edition, 5054
^ Surellas, Georges-Simon (1822), Notes sur l'Hydriodate de potasse et l'Acide hydriodique. -- Hydriodure de carbone; moyen d'obtenir, à l'instant, ce composé triple [Notes on the hydroiodide of potassium and on hydroiodic acid -- hydroiodide of carbon; means of obtaining instantly this compound of three elements] (in franch), Metz, France: Antoine, pp. 17–20, 28–29
^ James, Frank A. J. L. "Cooper, John Thomas (1790–1854), chemist". Oxford Dictionary of National Biography. Oxford University Press. Retrieved 26 January 2012.
^ Lyday, Phyllis A. (2005), "Iodine and Iodine Compounds", Ullmann's Encyclopedia of Industrial Chemistry (Wiley-VCH, Weinheim)

External links

"NIOSH Pocket Guide to Chemical Hazards #0343". National Institute for Occupational Safety and Health (NIOSH).
MSDS at JT Baker
A Method for the Specific Conversion of Iodoform to Carbon Dioxide
Article at 1911 Encyclopaedia Britannica
Preparation

English Journal

Dermatitis herpetiformis flare associated with use of triiodomethane packing strips for alveolar osteitis.

Katz KA, Roseman JE, Roseman RL, Katz SI.
Journal of the American Academy of Dermatology.J Am Acad Dermatol.2009 Feb;60(2):352-3. doi: 10.1016/j.jaad.2008.08.041.
PMID 19150286

LATE POISONING WITH CHLOROFORM AND OTHER ALKYL HALIDES IN RELATIONSHIP TO THE HALOGEN ACIDS FORMED BY THEIR CHEMICAL DISSOCIATION.

Graham EA1.
The Journal of experimental medicine.J Exp Med.1915 Jul 1;22(1):48-75.
The central lobular necrosis in the liver, which has been regarded by some writers as characteristic of late chloroform poisoning, has been produced experimentally with a number of other drugs. It is, therefore, in no sense peculiar to chloroform poisoning. Substances which have been shown to produc
PMID 19867902

Related Pictures

Triiodomethane - Stock Image - A700/0191 - Science Photo Library Structure and uses of Iodoform POC 1 Triiodomethane - YouTube Iodoform, 99+ %, Acros Organics™: Alkyl halides Organohalogen compounds | Fisher CAS No : 75-47-8 | Chemical Name : Triiodomethane | Pharmaffiliates Triiodomethane crystals - Stock Image - A500/0269 - Science Photo Library ヨードホルム(@triiodomethane) - Twilog The triiodomethane reaction. - Stock Image - C033/2889 - Science Photo Library Properties and reactions of Iodoform | Triiodomethane | - YouTube

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Iodoform
Names
	Other names Triiodomethane
Identifiers
CAS Registry Number	75-47-8
ATC code	D09AA13
Beilstein Reference	1697010
ChEBI	CHEBI:37758
ChEMBL	ChEMBL1451116
ChemSpider	6134
EC number	200-874-5
	InChI InChI=1S/CHI3/c2-1(3)4/h1H ; Key: OKJPEAGHQZHRQV-UHFFFAOYSA-N ;
Jmol-3D images	Image
KEGG	D01910
MeSH	iodoform
PubChem	6374
RTECS number	PB7000000
	SMILES IC(I)I ;
UNII	KXI2J76489
Properties
Chemical formula	CHI3
Molar mass	393.73 g·mol−1
Appearance	Pale, light yellow, opaque crystals
Odor	Saffron-like
Density	4.008 g mL−1
Melting point	119 °C (246 °F; 392 K)
Boiling point	218 °C (424 °F; 491 K)
Solubility in water	100 mg L−1
Solubility in diethyl ether	136 g L−1
Solubility in acetone	120 g L−1
Solubility in ethanol	78 g L−1
log P	3.118
Henry's law; constant (kH)	3.4 μmol Pa−1 kg−1
Structure
Crystal structure	Hexagonal
Coordination geometry	Tetragonal
Molecular shape	Tetrahedron
Thermochemistry
Specific; heat capacity (C)	157.5 J K−1 mol−1
Std enthalpy of; formation (ΔfHo298)	180.1–182.1 kJ mol−1
Std enthalpy of; combustion (ΔcHo298)	−716.9–−718.1 kJ mol−1
Hazards
GHS pictograms
GHS signal word	WARNING
GHS hazard statements	H315, H319, H335
GHS precautionary statements	P261, P280, P305+351+338
EU classification	Xn
R-phrases	R20/21/22, R36/37/38
S-phrases	S26, S36/37
NFPA 704	0 2 1
Flash point	204 °C (399 °F; 477 K)
	Lethal dose or concentration (LD, LC):
LD50 (Median dose)	355 mg kg−1 (oral, rat); 1180 mg kg−1 (dermal, rat); 1.6 mmol kg−1(s.c., mouse);
	US health exposure limits (NIOSH):
PEL (Permissible)	none
REL (Recommended)	0.6 ppm (10 mg/m3)
IDLH (Immediate danger	N.D.
Related compounds
Related haloalkanes	Methyl iodide; Diiodomethane; Carbon tetraiodide; Chloroform; Bromoform;
Related compounds	Guanidine; Pimagedine;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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	Infobox references