Diiodomethane or
methylene iodide is liquid
halomethaneHalomethane compounds are derivatives of methane with one or more of the hydrogen atoms replaced with halogen atoms . Halomethanes are both naturally occurring, especially in marine environments, and man-made, most notably as refrigerants, solvents, propellants, and fumigants...
insoluble in water, soluble in
etherEther is a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...
and
alcoholIn chemistry, an alcohol is any organic compound in which a hydroxyl group is bound to a carbon atom of an alkyl or substituted alkyl group. An important group of acohols is formed by the simple acyclic alcohols, the general formula for which is C
nH
2n+1OH...
. It has a relatively high
refractive indexThe refractive index of a medium is a measure of how much the speed of light is reduced inside the medium. For example, typical soda-lime glass has a refractive index close to 1.5, which means that in glass, light travels at 1 / 1.5 = 2/3 the speed of light in a vacuum...
of 1.741, and a surface tension of 0,0508 N·m
-1 . Fresh diiodomethane is a colorless liquid. However, exposure to light causes it to slowly decompose and liberate
iodineIodine , is a chemical element that has the symbol I and atomic number 53. Naturally-occurring iodine is a single isotope with 74 neutrons....
, which colours it brownish.
With its high specific gravity, it is used for the separation of minerals or for determination of specific gravity of mineral particles.
Discussion
Ask a question about 'Diiodomethane' Start a new discussion about 'Diiodomethane' Answer questions from other users |
Diiodomethane or
methylene iodide is liquid
halomethaneHalomethane compounds are derivatives of methane with one or more of the hydrogen atoms replaced with halogen atoms . Halomethanes are both naturally occurring, especially in marine environments, and man-made, most notably as refrigerants, solvents, propellants, and fumigants...
insoluble in water, soluble in
etherEther is a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...
and
alcoholIn chemistry, an alcohol is any organic compound in which a hydroxyl group is bound to a carbon atom of an alkyl or substituted alkyl group. An important group of acohols is formed by the simple acyclic alcohols, the general formula for which is C
nH
2n+1OH...
. It has a relatively high
refractive indexThe refractive index of a medium is a measure of how much the speed of light is reduced inside the medium. For example, typical soda-lime glass has a refractive index close to 1.5, which means that in glass, light travels at 1 / 1.5 = 2/3 the speed of light in a vacuum...
of 1.741, and a surface tension of 0,0508 N·m
-1 . Fresh diiodomethane is a colorless liquid. However, exposure to light causes it to slowly decompose and liberate
iodineIodine , is a chemical element that has the symbol I and atomic number 53. Naturally-occurring iodine is a single isotope with 74 neutrons....
, which colours it brownish.
With its high specific gravity, it is used for the separation of minerals or for determination of specific gravity of mineral particles. It is also used as a contact liquid for refractometers. Due to its possible toxicity, it should be replaced with safer heavy liquids. It is also used as a
solventA solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution.The most common solvent in everyday life is water. Most other commonly-used solvents are organic chemicals. These are called organic solvents...
and can be a
reaction intermediateA reaction intermediate or an intermediate is a molecular entity that is formed from the reactants and reacts further to give the directly observed products of a chemical reaction. Most chemical reactions are stepwise, that is they take more than one elementary step to complete...
, such as in the
Simmons-Smith reactionThe Simmons-Smith reaction is an organic reaction in which a carbenoid reacts with an alkene to form a cyclopropane. It is named after Howard Ensign Simmons, Jr. and R. D...
.
Preparation
Diiodomethane is commercially available. It may also be prepared by reducing
iodoformIodoform is the organoiodine compound with the formula CHI
3. A pale yellow, crystalline, volatile substance, it has a penetrating odor and, analogous to chloroform, sweetish taste...
with
sodium arseniteSodium arsenite is a compound with formula NaAsO2. It is the sodium salt of arsenous acid. It is a crystalline solid consisting of sodium cations, Na+, and catena-arsenite anions, [AsO2], which are infinite -O-As- chains, similar in structure to selenium dioxide,...
:
- CHI3 + Na3AsO3 + NaOH → CH2I2 + NaI + Na3AsO4
External links