Iodoform
| |||
Names | |||
---|---|---|---|
Preferred IUPAC name
Triiodomethane | |||
Other names | |||
Identifiers | |||
3D model (
JSmol ) |
|||
1697010 | |||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard
|
100.000.795 | ||
EC Number |
| ||
KEGG | |||
MeSH | iodoform | ||
PubChem CID
|
|||
RTECS number
|
| ||
UNII | |||
CompTox Dashboard (EPA)
|
|||
| |||
| |||
Properties | |||
CHI3 | |||
Molar mass | 393.732 g·mol−1 | ||
Appearance | Pale, light yellow, opaque crystals | ||
Odor | Saffron-like[3] | ||
Density | 4.008 g/cm3[3] | ||
Melting point | 119 °C (246 °F; 392 K)[3] | ||
Boiling point | 218 °C (424 °F; 491 K)[3] | ||
100 mg/L[3] | |||
Solubility in diethyl ether | 136 g/L | ||
Solubility in acetone | 120 g/L | ||
Solubility in ethanol | 78 g/L | ||
log P | 3.118 | ||
Henry's law
constant (kH) |
3.4 μmol·Pa−1·kg−1 | ||
−117.1·10−6 cm3/mol | |||
Structure | |||
Hexagonal | |||
Tetrahedral at C | |||
Thermochemistry | |||
Heat capacity (C)
|
157.5 J/(K·mol) | ||
Std enthalpy of (ΔfH⦵298)formation |
180.1 – 182.1 kJ/mol | ||
Std enthalpy of (ΔcH⦵298)combustion |
−716.9 – −718.1 kJ/mol | ||
Pharmacology | |||
D09AA13 (WHO) | |||
Hazards | |||
GHS labelling: | |||
Warning | |||
H315, H319, H335 | |||
P261, P280, P305+P351+P338 | |||
NFPA 704 (fire diamond) | |||
Flash point | 204 °C (399 °F; 477 K) | ||
Lethal dose or concentration (LD, LC): | |||
LD50 (median dose)
|
| ||
NIOSH (US health exposure limits): | |||
PEL (Permissible)
|
none[4] | ||
REL (Recommended)
|
0.6 ppm (10 mg/m3)[4] | ||
IDLH (Immediate danger) |
N.D.[4] | ||
Related compounds | |||
Related compounds
|
|||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Iodoform (also known as triiodomethane) is the
Naming
The name iodoform originates with the "formyle radical," an archaic term for the HC moiety, and is retained for historical consistency. A full, modern name is triiodomethane. The "hydride" in the latter is sometimes omitted,[2] but the IUPAC recommends against doing so, as "carbon triiodide" could also mean C2I6 (hexaiodoethane, a highly unstable compound).
Structure
The molecule adopts a tetrahedral geometry with C3v symmetry.
Synthesis and reactions
The synthesis of iodoform was first described by Georges-Simon Serullas 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;[6] and at much the same time independently by John Thomas Cooper.[7] 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: 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
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
The
Applications
The compound finds small-scale use as a disinfectant.
See also
- Iodoform reaction
- Fluoroform
- Chloroform
- Bromoform
References
Randhawa GK, Graham R, Matharu KS, Bismuth Iodoform Paraffin Paste: History and uses. British Journal of Oral and Maxillofacial Surgery. 2019;67:E53-E54.
- ISBN 978-0-85404-182-4.
The retained names 'bromoform' for HCBr3, 'chloroform' for HCCl3, and 'iodoform' for HCI3 are acceptable in general nomenclature. Preferred IUPAC names are substitutive names.
- ^ a b "Iodoform".
- ^ a b c d e f g Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
- ^ 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 French), Metz, France: Antoine, pp. 17–20, 28–29
- doi:10.1093/ref:odnb/39361. Retrieved 26 January 2012. (Subscription or UK public library membershiprequired.)
- ISBN 9783527306732
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
- Preparation
- Encyclopædia Britannica. Vol. 14 (11th ed.). 1911. p. 726. .