Diiodomethane Identifiers CAS number PubChem ChemSpider EC number RTECS number PA8575000 Jmol-3D images Image 1 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
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 S-phrases , , NFPA 704 Flash point 113 °C (what is: /?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Diiodomethane or methylene iodide, commonly abbreviated "MI", is a liquid organoiodine compound. It is insoluble in water, but 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. 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 is also used as a contact liquid for refractometers. Diiodomethane is a reagent in the Simmons-Smith reaction, serving as a source of methylene CH2.
- CHI3 + Na3AsO3 + NaOH → CH2I2 + NaI + Na3AsO4
- CH2Cl2 + 2 NaI → CH2I2 + 2 NaCl
Alkyl iodides are alkylating agents and contact should be avoided.
- ^ Website of Krüss (8.10.2009)
- ^ 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
- ^ a b Roger Adams, C. S. Marvel (1941), "Methylene Iodide", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0358 ; Coll. Vol. 1: 358
Halomethanes Monosubstituted Disubstituted Trisubstituted
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