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Diiodomethane: Difference between revisions

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{{chembox {{Chembox
| Watchedfields = changed
| verifiedrevid = 401994382
| verifiedrevid = 445810515
| ImageFile = Structural formula of diiodomethane.svg
| ImageFile_Ref = {{chemboximage|correct|??}} | ImageFile_Ref = {{chemboximage|correct|??}}
| ImageSize = 120
| ImageFile = Diiodomethane.png
| ImageName = Stereo, skeletal formula of diiodomethane with all explicit hydrogens added
| ImageSize = 120px
| ImageFileL1 = Diiodomethane-3D-balls.png | ImageFileL1 = Diiodomethane-3D-balls.png
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| ImageNameL1 = Ball and stick model of diiodomethane
| ImageFileR1 = Diiodomethane-3D-vdW.png | ImageFileR1 = Diiodomethane-3D-vdW.png
| ImageFileR1_Ref = {{chemboximage|correct|??}}
| IUPACName = Diiodomethane
| ImageNameR1 = Spacefill model of diiodomethane
| OtherNames = Methylene iodide, Methylene diiodide, Methyl diiodide
| ImageFile2 = Diiodomethane2.png
| Section1 = {{Chembox Identifiers
| PIN = Diiodomethane<ref>{{Cite web|title=methylene iodide - Compound Summary|url=https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=6346&loc=ec_rcs|work=PubChem Compound|publisher=National Center for Biotechnology Information|access-date=27 February 2012|location=USA|date=26 March 2005|at=Identification ad Related Records}}</ref>
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|Section1={{Chembox Identifiers
| CASNo = 75-11-6
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 3J731705OX
| PubChem = 6346
| ChemSpiderID = 6106 | ChemSpiderID = 6106
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| InChIKey = NZZFYRREKKOMAT-UHFFFAOYAO
| EINECS = 200-841-5
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| MeSHName = methylene+iodide
| RTECS = PA8575000
| Beilstein = 1696892
| SMILES = ICI
| StdInChI = 1S/CH2I2/c2-1-3/h1H2 | StdInChI = 1S/CH2I2/c2-1-3/h1H2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = NZZFYRREKKOMAT-UHFFFAOYSA-N | StdInChIKey = NZZFYRREKKOMAT-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| CASNo = 75-11-6
}}
| CASNo_Ref = {{cascite|correct|CAS}}
|Section2={{Chembox Properties
| EINECS = 200-841-5
| PubChem = 6346 | C = 1
| SMILES = ICI | H = 2
| I = 2
| InChI = 1/CH2I2/c2-1-3/h1H2
| Appearance = Colorless liquid
| RTECS = PA8575000
| Density = 3.325 g mL<sup>−1</sup> (3325 kg/m<sup>3</sup>)
}}
| MeltingPtK = 278.5 to 279.3
| Section2 = {{Chembox Properties
| BoilingPtK = 455.2
| Formula = CH<sub>2</sub>I<sub>2</sub>
| Solubility = 1.24 g L<sup>−1</sup> (at 20&nbsp;°C)<ref>{{Cite web | url=http://www.surface-tension.de/LIQUIDS/Diiodomethane3.htm | title=Diiodomethane }}</ref>
| MolarMass = 267.84 g/mol
| HenryConstant = 23 μmol Pa<sup>−1</sup> kg<sup>−1</sup>
| Appearance = Colorless liquid with chloroform-like odour
| Density = 3.325 g/cm<sup>3</sup> | MagSus = -93.10·10<sup>−6</sup> cm<sup>3</sup>/mol
}}
| MeltingPtC = 6
|Section3={{Chembox Structure
| BoilingPt = 181 °C (358 °F) (decomp.)
| Coordination = Tetragonal
| Solubility = 14 g/l at 20 °C
| MolShape = Tetrahedron
}}
}}
| Section3 = {{Chembox Hazards
|Section4={{Chembox Thermochemistry
| ExternalMSDS = ,
| DeltaHf = 67.7–69.3 kJ mol<sup>−1</sup>
| EUClass = Harmful ('''Xn''')
| DeltaHc = −748.4–−747.2 kJ mol<sup>−1</sup>
| MainHazards =
| HeatCapacity = 133.81 J K<sup>−1</sup> mol<sup>−1</sup>
| FlashPt = 113 °C
}}
| Autoignition =
|Section5={{Chembox Hazards
| NFPA-H = 3
| ExternalSDS =
| NFPA-F = 1
| GHSPictograms = {{GHS corrosion}} {{GHS exclamation mark}}
| NFPA-R = 0
| GHSSignalWord = '''DANGER'''
| NFPA-O =
| RPhrases = {{R20/22}} | HPhrases = {{H-phrases|302|315|318|335}}
| PPhrases = {{P-phrases|261|280|305+351+338}}
| SPhrases = {{S26}}, {{S27}}, {{S36/37/39}}
| NFPA-H = 3
}}
| NFPA-F = 1
| NFPA-R = 0
| FlashPtC = 110
}}
|Section6={{Chembox Related
| OtherFunction_label = alkanes/haloalkanes
| OtherFunction = {{Unbulleted list|]|]|]|]|]|]|]}}
}}
}} }}


'''Diiodomethane''' or '''methylene iodide''', commonly abbreviated "MI", is a liquid ]. It is insoluble in water, but soluble in ] and ]. It has a relatively high ] of 1.741, and a surface tension of 0.0508 N·m<sup>−1</sup>.<ref name="KRÜSS">'''' (8.10.2009)</ref> Diiodomethane is a colorless liquid, however, it decomposes upon exposure to light liberating ], which colours samples brownish. '''Diiodomethane''' or '''methylene iodide''', commonly abbreviated "MI", is an ]. Diiodomethane is a very dense colorless liquid; however, it decomposes upon exposure to light liberating ], which colours samples brownish. It is slightly soluble in water, but soluble in organic solvents. It has a very high ] of 1.741, and a ] of 0.0508 N·m<sup>−1</sup>.<ref name="KRÜSS">'' {{Webarchive|url=https://web.archive.org/web/20131201023708/http://www.kruss.de/en/theory/substance-properties/liquids.html |date=2013-12-01 }}'' (8.10.2009)</ref>


==Uses==
With its high ], diiodomethane is used in the determination of the density of mineral and other solid samples. It is also used as a contact liquid for ]s. Diiodomethane is a ] in the ], serving as a source of ] {{chem|CH|2}}.<ref>Two cyclopropanation reactions: {{OrgSynth | author = Smith, R. D.; Simmons, H. E. | title = Norcarane | collvol = 5 | collvolpages = 855 | prep = cv5p0855}}, {{OrgSynth | author = Ito, Y.; Fujii, S.; Nakatuska, M.; Kawamoto, F.; Saegusa, T. | collvol = 6 | collvolpages = 327 | year = 1988 | prep = cv6p0327 | title = One-Carbon Ring Expansion Of Cycloalkanones To Conjugated Cycloalkenones: 2-Cyclohepten-1-one}}</ref>
Because of its high ], diiodomethane is used in the determination of the density of mineral and other solid samples. It can also be used as an optical contact liquid, in conjunction with the gemmological refractometer, for determining the refractive index of certain gemstones.

Diiodomethane is a ] for installing the CH<sub>2</sub> group. In the ], it is a source of ].<ref>Two cyclopropanation reactions: {{OrgSynth | author = Smith, R. D. | author2 = Simmons, H. E. | title = Norcarane | collvol = 5 | collvolpages = 855 | prep = cv5p0855}}, {{OrgSynth | author = Ito, Y. | author2 = Fujii, S. | author3 = Nakatuska, M. | author4 = Kawamoto, F. | author5 = Saegusa, T. | collvol = 6 | collvolpages = 327 | year = 1988 | prep = cv6p0327 | title = One-Carbon Ring Expansion Of Cycloalkanones To Conjugated Cycloalkenones: 2-Cyclohepten-1-one}}</ref> In fact the Simmons–Smith reaction does not produce free carbene but proceeds via Zn-CH<sub>2</sub>I intermediates.

Diiodomethane is also a source of the equivalent of {{chem2|CH2(2+)}}. The synthesis of Fe<sub>2</sub>(CH<sub>2</sub>)(CO)<sub>8</sub> illustrates this reactivity:<ref>{{cite journal |doi=10.1021/ja00525a062|title=Synthesis, Crystal Structure, and Chemical Reactivity of Octacarbonyl-μ-methylene-diiron|year=1980|last1=Sumner|first1=Charles E.|last2=Riley|first2=Paul E.|last3=Davis|first3=Raymond E.|last4=Pettit|first4=R.|journal=Journal of the American Chemical Society|volume=102|issue=5|pages=1752–1754}}</ref>
:Na<sub>2</sub>Fe<sub>2</sub>(CO)<sub>8</sub> + CH<sub>2</sub>I<sub>2</sub> → Fe<sub>2</sub>(CH<sub>2</sub>)(CO)<sub>8</sub> + 2{{nbsp}}NaI


==Preparation== ==Preparation==
Diiodomethane can be prepared from the widely available solvent ] by the action of ] in ] in the ]:<ref name=OS/>
Although commercially available, it can be prepared by reducing ] with ]:<ref name=OS>{{OrgSynth | title = Methylene Iodide | collvol = 1 | collvolpages = 358 | prep = cv1p0358 | author = Roger Adams, C. S. Marvel | year = 1941}}</ref>
:CHI<sub>3</sub> + Na<sub>3</sub>AsO<sub>3</sub> + NaOH &rarr; CH<sub>2</sub>I<sub>2</sub> + NaI + Na<sub>3</sub>AsO<sub>4</sub> :CH<sub>2</sub>Cl<sub>2</sub> + 2 NaI → CH<sub>2</sub>I<sub>2</sub> + 2 NaCl


It can also be prepared by reducing ] with elemental ]<ref>{{cite book|last=Miller|first=William Allen|title=Elements of Chemistry: Chemistry of carbon compounds|edition=5th|year=1880|publisher=Longmans Green and Co.|location=London|page=|url=https://archive.org/details/elementschemist01grovgoog}}</ref> or ]:<ref name=OS>{{OrgSynth | title = Methylene Iodide | volume = 1 | pages = 57 | doi = 10.15227/orgsyn.001.0057 | author = Roger Adams | author2 = C. S. Marvel | year = 1921}}</ref>
Diiodomethane can also be prepared from ] by the action of ] in acetone in the ]:<ref name=OS/>
:CH<sub>2</sub>Cl<sub>2</sub> + 2 NaI &rarr; CH<sub>2</sub>I<sub>2</sub> + 2 NaCl :CHI<sub>3</sub> + Na<sub>3</sub>AsO<sub>3</sub> + NaOH → CH<sub>2</sub>I<sub>2</sub> + NaI + Na<sub>3</sub>AsO<sub>4</sub>


==Safety== ==Safety==
Alkyl iodides are ]s and contact should be avoided. Alkyl iodides are ]s, which are potential mutagens.


==References== ==References==
{{Reflist}}
<references/>


==External links== ==External links==
* *
* * {{Webarchive|url=https://web.archive.org/web/20120211080357/http://www.agu.org/pubs/crossref/2003/2002JD002452.shtml |date=2012-02-11 }}


{{Halomethanes}} {{Halomethanes}}


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Diiodomethane: Difference between revisions Add topic