Iodoform 315028 211219834 2008-05-09T08:55:23Z Puppy8800 5404759 iw :''The term 'iodoform' was also used in World War II to refer to [[group key]]s sent to agents in Europe by the Special Operations Executive: this usage is unrelated to the chemical.'' {{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 = }} }} 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 enthalpy 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]] For this reason iodoform was traditionally used as a test for [[methyl ketone]]; if a methyl ketone is present in the solution, a yellow precipitate will form. This is known as the [[iodoform test]]. == 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]] [[bg:Йодоформ]] [[cs:Jodoform]] [[de:Iodoform]] [[it:Iodoformio]] [[lv:Jodoforms]] [[hu:Jodoform]] [[ja:ヨードホルム]] [[pl:Jodoform]] [[pt:Iodofórmio]] [[ru:Иодоформ]] [[tr:İyodoform]] [[zh:碘仿]]