Diiodomethane
IUPAC name	Diiodomethane
Other names	Methylene iodide, Methylene diiodide, Methyl diiodide
Identifiers
CAS number	75-11-6 Y
PubChem	6346
EC number	200-841-5
RTECS number	PA8575000
SMILES	ICI
InChI	1/CH2I2/c2-1-3/h1H2
InChI key	NZZFYRREKKOMAT-UHFFFAOYAO
ChemSpider ID	6106
Properties
Molecular formula	CH2I2
Molar mass	267.84 g/mol
Appearance	Colorless liquid with chloroform-like odour
Density	3.325 g/cm3
Melting point	6 °C, 279 K, 43 °F
Boiling point	181 °C (358 °F) (decomp.)
Solubility in water	14 g/l at 20 °C
Hazards
MSDS	MSDS at the University of Oxford, J.T.Baker MSDS
EU classification	Harmful (Xn)
R-phrases	R20/22
S-phrases	S26, S27, S36/37/39
NFPA 704	1 3 0
Flash point	113 °C
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Diiodomethane or methylene iodide, commonly abbreviated "MI", is a liquid organoiodine compound insoluble in water, soluble in ether and alcohol. It has a relatively high refractive index of 1.741, and a surface tension of 0,0508 N·m^{-1 [1]}. Diiodomethane is a colorless liquid, however, it decomposes upon exposure to light liberating iodine, which colours samples brownish.

With its high specific gravity, diiodomethane is used in the determination of the density of mineral and other solid samples. It has been used for separation of minerals.^{[citation needed]} It is also used as a contact liquid for refractometers. Diiodomethane is a reagent in the Simmons-Smith reaction, serving as a source of methylene.^[2]

Contents 1 Preparation 2 Safety 3 References 4 External links

[edit] Preparation

Although commercially available, it can be prepared by reducing iodoform with sodium arsenite:^[3]

CHI₃ + Na₃AsO₃ + NaOH → CH₂I₂ + NaI + Na₃AsO₄

[edit] Safety

Alkyl iodides are alkylating agents and contact should be avoided.

[edit] References

1. ^ Website of Krüss (8.10.2009)
2. ^ Two cyclopropanation reactions: Smith, R. D.; Simmons, H. E., "Norcarane", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv5p0855 ; Coll. Vol. 5: 855 , Ito, Y.; Fujii, S.; Nakatuska, M.; Kawamoto, F.; Saegusa, T. (1988), "One-Carbon Ring Expansion Of Cycloalkanones To Conjugated Cycloalkenones: 2-Cyclohepten-1-one", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv6p0327 ; Coll. Vol. 6: 327 
3. ^ Roger Adams, C. S. Marvel (1941), "Methylene Iodide", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0358 ; Coll. Vol. 1: 358 

[edit] External links

• Diiodomethane data sheet
• New particle formation from photooxidation of diiodomethane

v • d • e Halomethanes Monosubstituted CH3F · CH3Cl · CH3Br · CH3I Disubstituted CH2F2 · CH2ClF · CH2BrF · CH2FI · CH2Cl2 · CH2BrCl · CH2ClI · CH2Br2 · CH2BrI · CH2I2 Trisubstituted CHF3 · CHClF2 · CHBrF2 · CHF2I · CHCl2F · C*HBrClF · C*HClFI · CHBr2F · C*HBrFI · CHFI2 · CHCl3 · CHBrCl2 · CHCl2I · CHBr2Cl · C*HBrClI · CHClI2 · CHBr3 · CHBr2I · CHBrI2 · CHI3 Tetrasubstituted CF4 · CClF3 · CBrF3 · CF3I · CCl2F2 · CBrClF2 · CClF2I · CBr2F2 · CBrF2I · CF2I2 · CCl3F · CBrCl2F · CCl2FI · CBr2ClF · C*BrClFI · CClFI2 · CBr3F · CBr2FI · CBrFI2 · CFI3 · CCl4 · CBrCl3 · CCl3I · CBr2Cl2 · CBrCl2I · CCl2I2 · CBr3Cl · CBr2ClI · CBrClI2 · CClI3 · CBr4 · CBr3I · CBr2I2 · CBrI3 · CI4 * Chiral compound.