Diiodomethane Property

Melting point:

6 °C

Boiling point:

67-69 °C11 mm Hg(lit.)

Density 

3.325 g/mL at 25 °C(lit.)

vapor density 

9.25 (vs air)

refractive index 

1.737

Flash point:

181°C

storage temp. 

Store below +30°C.

solubility 

0.8g/l

form 

Liquid

Specific Gravity

3.325

color 

deep yellow

Water Solubility 

14 g/L (20 ºC)

Sensitive 

Light Sensitive

Merck 

14,6066

BRN 

1696892

Dielectric constant

5.3（-4℃）

Stability:

Stable. Incompatible with strong oxidizing agents, strong bases. Reacts violently with alkali metal salts. May discolour on exposure to light.

CAS DataBase Reference

75-11-6(CAS DataBase Reference)

NIST Chemistry Reference

Methane, diiodo-(75-11-6)

EPA Substance Registry System

Methylene iodide (75-11-6)

Safety

Hazard Codes 

Xi,Xn

Risk Statements 

36/37/38-22-20/21/22

Safety Statements 

26-37/39-36/37/39

RIDADR 

2810

WGK Germany 

3

RTECS 

PA8575000

F 

8

TSCA 

Yes

HazardClass 

6.1

PackingGroup 

III

HS Code 

29033080

Toxicity

LD50 orally in Rabbit: 76 mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H332Harmful if inhaled

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P301+P310IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

Diiodomethane Chemical Properties,Usage,Production

Description

Diiodomethane (CH2I2) is an iodine containing organic compound. Its decomposition in acetonitrile initiated by 310nm light has been investigated. Femtosecond pump-probe spectroscopic and ab initio molecular dynamics simulations studies of the photodecomposition of CH2I2 suggest the formation of the isomer of diiodomethane (CH2I-I) as hot photoproduct. In the atmosphere, it undergoes photolysis in the presence of ozone to afford iodine oxide (IO) which results in the formation of aerosols. Its vacuum ultraviolet (VUV) photoabsorption spectrum has been reported.

Diiodomethane has been used as a probe liquid for evaluation of the polar and dispersive components of the surface energy of the catecholamine coated fiber surfaces. It may be used for the preparation of cyclopropyl ketones, esters and amides.
Diiodomethane may be used as a probe solvent in contact angle measurement to analyze the hydrophilicity of polymer surfaces.
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Chemical Properties

Diiodomethane is a light yellow or gold liquid with chloroform-like odour. It has a relative density of 3.325 at 20°C and can be mixed with benzene to produce liquids with different densities. These mixtures are used in the determination of the refractive indices of minerals and for the separation of minerals according to density.

Uses

Diiodomethane is used to determine the density of minerals and other solid samples due to its high density. It is used as an optical contact liquid to determine the refractive index of certain gemstones. In simmons-smith reaction, it acts as a reagent to generate methylene (carbine) free radical. It reacts with olefins to prepare cyclopropanes with high stereo specificity.

Application

Diiodomethane is used as the dispersive (non-polar) liquid while de-ionized water and glycerol as polar liquids. It is also used in separating mixtures of minerals. In determining the specific gravity of minerals and other substances. In the manufacture of x-ray contrast media.

General Description

Diiodomethane (CH₂I₂) is an iodine containing organic compound. Its decomposition in acetonitrile initiated by 310nm light has been investigated. Femtosecond pump-probe spectroscopic and ab initio molecular dynamics simulations studies of the photodecomposition of CH₂I₂ suggest the formation of the isomer of diiodomethane (CH₂I-I) as hot photoproduct. In the atmosphere, it undergoes photolysis in the presence of ozone to afford iodine oxide (IO) which results in the formation of aerosols. Its vacuum ultraviolet (VUV) photoabsorption spectrum has been reported.

Hazard

May be irritating and narcotic.
Diiodomethane has the advantages of high opacity,ease of penetration,and ease of removal because it evaporates fairly quickly.However,it can cause skin burns.

Synthesis

Diiodomethane can be prepared from the widely available solvent dichloromethane by the action of sodium iodide in acetone in the Finkelstein reaction:
CH2Cl2 + 2 NaI → CH2I2 + 2 NaCl.
It can also be prepared by reducing iodoform with elemental phosphorus or sodium arsenite:
CHI3 + Na3AsO3 + NaOH → CH2I2 + NaI + Na3AsO.
Diiodomethane is prepared by reacting iodoform with sodium acetate in ethanol.

Purification Methods

Fractionally distil it under reduced pressure, then fractionally crystallise it by partial freezing, and stabilize it with silver wool if necessary. It has also been purified by drying over CaCl2 and fractionally distilling from Cu powder. Store it in the dark. [Beilstein 1 IV 97.]