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Dimethylamine



Dimethylamine
IUPAC name Dimethylamine
Identifiers
CAS number 124-40-3
SMILES CNC
Properties
Molecular formula C2H7N
Molar mass 45.08 g/mol
Appearance Colorless gas with pungent odor
Density 1.883 kg/m3 (21 °C, 1 atm)
Melting point

−92.2 °C

Boiling point

7 °C

Solubility in water 354 g/100 ml
Dipole moment  ?
Thermochemistry
Std enthalpy of
formation
ΔfHo298
 ? kJ/mol
Standard molar
entropy
So298
 ? J/K/mol
Hazards
EU classification Highly flammable (F+)
Harmful (Xn)
EU Index 612-001-00-9
NFPA 704
4
3
0
 
R-phrases R12, R20, R37/38, R41
S-phrases (S2), S16, S26, S39
Flash point Flammable gas
Autoignition
temperature
400 °C
Explosive limits 2.8–14.4%
RTECS number IP8750000
Related Compounds
Related amine Methylamine
Trimethylamine
Diethylamine
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Dimethylamine or N-methylmethanamine or DMA is an organic compound and an amine. It is a colorless, liquefied and flammable gas with an ammonia and fish-like odor. Dimethylamine is generally used as a solution in water at concentrations up to around 40%.

Contents

Chemistry

Dimethylamine is a secondary amine. The molecule consists of a nitrogen atom with two methyl substituents and one proton. Dimethylamine is a base and the pKa of the ammonium salt CH3-NH2+-CH3 is 10.73, a value intermediate between methylamine (10.64) and trimethylamine (9.79). Dimethylamine reacts with acids to form salts. Dimethylamine hydrochloride is an odorless white solid with a melting point of 171.5 °C. Dimethylamine is produced by catalytic reaction of methanol and ammonia at elevated temperatures and high pressure.[1]

Biochemistry

The German cockroach utilizes dimethylamine as a pheromone for communication.

DMA undergoes nitrosation under weak acid conditions to give dimethlynitrosamine. This animal carcinogen has been detected and quantified in human urine samples and it may also arise from nitrosation of DMA by nitrogen oxides present in acid rain in highly industrilized countries (Zhang et al. 1998).

Uses

Dimethylamine is used as dehairing agent in tanning, in dyes, in rubber accelerators, in soaps and cleaning compounds and as an agricultural fungicide. In industry dimethylamine is converted to dimethylformamide and the surfactant lauryl dimethylamine oxide. It is raw material in the production of many pharmaceuticals such as diphenhydramine and also that of the chemical weapon tabun.

See also

References

  1. ^ Corbin D.R.; Schwarz S.; Sonnichsen G.C. (1997). "Methylamines synthesis: A review". Catalysis Today 37 (2): 71-102. doi:10.1016/S0920-5861(97)00003-5.

Zhang AQ, Mithchell SC, Smith RL (1998) Dimethylamine formation in the rat from various related amine precursors. Food Chem Toxicol 36(11):923-7

 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Dimethylamine". A list of authors is available in Wikipedia.
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