The dimethylamine is an organic compound formed by two methyl groups -CH3 attached to a -NH group. Its chemical formula is (CH3)twoNH. It is a colorless gas. When it is in the air at low concentrations a fishy odor is perceived. However, if it is in high concentration it has the smell of ammonia NH3.
Dimethylamine is present in plants and animals. It is believed that in humans it comes from the breakdown of certain enzymes but also from the ingestion of some foods such as fish. If dimethylamine gas dissolves in water, it forms highly alkaline and corrosive solutions..
It has various industrial uses such as to produce solvents, to accelerate the vulcanization of rubber, to inhibit the corrosion of pipes, to make soaps, to prepare colorants and to absorb acid gases in certain processes..
Dimethylamine is a highly flammable gas. Containers should not be exposed to heat or fire as they may explode. In addition, its vapors are irritating to the eyes, the skin and the respiratory tract..
It is a compound that may be part of atmospheric aerosols, that is, very fine droplets found in the atmosphere.
Dimethylamine is a secondary aliphatic amine. This means that the nitrogen substituents (N) are aliphatic (-CH3), which means that they are not aromatic, and that they are two. Therefore they are two methyls -CH3 attached to nitrogen, which also has a hydrogen (H).
In the dimethylamine molecule, nitrogen (N) has a pair of free electrons, that is, a pair of electrons that are not bound to any other atom..
- N, N-Dimethylamine
- DMA (acronym for Di-Methyl-Amine).
45.08 g / mol
-6.69 ºC (closed cup method).
400 ° C
Liquid = 0.6804 g / cm3 at 0 ºC.
Vapor = 1.6 (relative density with respect to air, air = 1).
Very soluble in water: 163 g / 100 g of water at 40 ° C. Soluble in ethanol and ethyl ether.
Aqueous dimethylamine solutions are strongly alkaline.
Kb = 5.4 x 10-4
pKto conjugated acid = 10.732 at 25 ° C. The conjugated acid is the dimethylammonium ion: (CH3) NHtwo+
Liquid Dimethylamine can attack some plastics, rubbers, and coatings.
When dissolved in water, nitrogen's free electron pair (N) takes on a proton (H+) from the water, leaving an OH free-, so it forms very alkaline and corrosive solutions:
Dimethylamine + Water → Dimethylammonium Ion + Hydroxyl Ion
(CH3)twoNH + HtwoO → (CH3)twoNHtwo+ + Oh-
With nitric acid you get a nitrate salt, that is, dimethylammonium nitrate:
Dimethylamine + Nitric Acid → Dimethylammonium Nitrate
(CH3)twoNH + HNO3 → (CH3)twoNHtwo+NOT3-
When it is in low concentration in the air it has a fish-like odor, while in high concentrations it smells like ammonia (NH3).
In the body, dimethylamine can undergo nitrosation under weakly acidic conditions to give dimethylnitrosamine a carcinogenic compound (CH3)twoN-NO.
The formation of dimethyl nitrosamine occurs from dimethylamine and nitrite (sodium nitrite) in the stomach (at pH 5-6) by the action of bacteria in the gastrointestinal tract. Sodium nitrite is present in some foods.
Dimethylamine + Sodium Nitrite → Dimethylnitrosamine + Sodium Hydroxide
(CH3)twoNH + NaNOtwo → (CH3)twoN-NO + NaOH
Dimethylamine is prepared commercially by reacting methanol (CH3OH) with ammonia (NH3) at 350-450 ° C in the presence of a silica-alumina catalyst (SiOtwo/To thetwoOR3).
2 CH3OH + NH3 → (CH3)twoNH + 2 HtwoOR
Since monomethylamine and trimethylamine are also produced, purification is carried out in a series of four to five distillation columns..
Dimethylamine is found in plants and animals. It is also present naturally and abundantly in human urine..
It is estimated that its presence in humans is due to the fact that it is produced by certain types of intestinal bacteria from some compounds found in food.
Some of these compounds are choline (a compound that is associated with the group of B vitamins) and trimethylamine oxide. It is also believed to come from an enzyme that inhibits nitric oxide (NO) that is formed in the body..
Certain sources of information indicate that the increase in dimethylamine in the urine is caused by the ingestion of fish and seafood, where the highest values are obtained when squid, hake, sardines, swordfish, cod, whiting and ray are eaten..
Dimethylamine is considered to be a uremic toxin, that is, a substance that can cause harm if its concentration in the urine is too high. In fact, very high levels of dimethylamine have been observed in patients with end-stage renal disease..
It is believed that in these patients there may be an overpopulation of intestinal bacteria that could be producing it.
Dimethylamine or DMA is used to:
- Preparation of other compounds.
- Production of the solvents dimethylformamide and dimethylacetamide.
- Accelerate the vulcanization of certain rubbers.
- Remove hair from hides during tanning.
- Act as an antioxidant for solvents.
- Serve as a mineral flotation agent.
- Inhibit corrosion and as an anti-fouling agent for pipes.
- Function as a surfactant.
- Make soaps and detergents.
- Act as a textile chemist.
- Function as an antiknock agent in fuels and as a stabilizer for gasoline.
- Prepare colorants.
- Absorb acid gases.
- Serve as a propellant for pesticides and rockets.
- Be part of agents for water treatment.
- Act as a fungicide in agrochemical products.
- Discontinued uses such as attracting and killing weevils or insects that attack cotton.
Dimethylamine vapors are irritating to the skin, eyes and respiratory tract..
If it comes into contact with the skin in liquid form, it can cause frostbite and chemical burns. Its inhalation has adverse health effects.
DMA gas is corrosive and can form corrosive aqueous solutions. Your aqueous solutions can become flammable unless well diluted..
Dimethylamine in gas form easily ignites producing toxic fumes of nitrogen oxides (NOx).
If the container containing this gas is exposed to fire or intense heat, it may explode..
The atmospheric aerosol (very small droplets of mixture of natural compounds and / or pollutants in the atmosphere) has a profound impact on the global climate and on air quality in the various regions of the world..
The formation of the new aerosol particles is not yet fully understood.
It is estimated that dimethylamine participates together with other compounds in the formation of these particles, which seems to depend on the fact that there are strong emissions of DMA in the area..
For example, in industrial areas there is a higher concentration than in agricultural areas, and this may influence the way in which the WFD participates..
It is noteworthy that, according to some scientists, the burning of plant material containing glyphosate (one of the most widely used herbicides in the world), can lead to the formation of dimethylamine.