Trimethylamine
| Names | |
|---|---|
| IUPAC name
N,N-Dimethylmethanamine
| |
| Other names
N,N,N-Trimethylmethanamine
N-Trimethylamine TMA | |
| Properties | |
| C3H9N N(CH3)3 | |
| Molar mass | 59.112 g/mol |
| Appearance | Colorless gas |
| Odor | Fishy, ammoniacal |
| Density | 0.670 g/cm3 (0 °C) (liquid) |
| Melting point | −117.08 °C (−178.74 °F; 156.07 K) |
| Boiling point | 3 °C (37 °F; 276 K) |
| Miscible | |
| Solubility | Reacts with acids Miscible with alcohols, aromatics, esters, ethers, halocarbons |
| Vapor pressure | 1610 mmHg at 25 °C |
| Thermochemistry | |
| Std enthalpy of
formation (ΔfH |
−24.5 kJ/mol |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | −7 °C (19 °F; 266 K) |
| Lethal dose or concentration (LD, LC): | |
| LD50 (Median dose)
|
500 mg/kg (rat, oral) |
| Related compounds | |
| Related compounds
|
Methylamine Dimethylamine |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Trimethylamine (TMA) is an organic compound, a tertiary amine with the formula N(CH3)3.
Contents
Properties
Chemical
Trimethylamine reacts with acids forming trimethylammonium salts.
Trimethylamine is a Lewis base that forms adducts with a variety of Lewis acids.
Physical
Trimethylamine is a colorless gas with a fish-like odor at low concentrations (the odor associated with rotting fish), changing to ammonia-like odor at higher concentrations. It is highly soluble in water as well as many other organic solvents, like alcohols, aromatics and ethers.
Availability
Trimethylamine can be bought from chemical suppliers, either as anhydrous, in gas cylinders, as solution in water or alcohol, or as salt.
Preparation
Trimethylamine is prepared by the reaction of ammonia and methanol, in the presence of a catalyst:[1]
- 3 CH3OH + NH3 → (CH3)3N + 3 H2O
Methylamine and dimethylamine may be produced as side products.
Reaction of ammonium chloride and formaldehyde or paraformaldehyde will yield the hydrochloride salt of trimethylamine:[2]
- 9 (CH2=O)n + 2n NH4Cl → 2n (CH3)3N·HCl + 3n H2O + 3n CO2
A strong base, like sodium hydroxide, can be used to obtain the freebase trimethylamine from its salt.
Projects
- Make trimethylamine hydrochloride
- Synthesis of choline
- Synthesis of trimethylamine N-oxide (TMAO)
Handling
Safety
Trimethylamine is a foul-smelling toxic gas, that is also corrosive. Proper protection must be worn when handling this compound, like gloves, gas mask and lab coat. Work must be one either outside or in a well ventilated area.
Storage
Trimethylamine can be kept in gas cylinders or lecture bottles, as well as aq. or alcoholic solutions, in a well ventilated, cold dark place. The anhydrous form must not be kept in a standard bottle in a freezer, as in the event of power outage, the trimethylamine will warm up to room temperature and will expand, certainly rupturing the bottle.
The best way to safely store this compound is in salt form, as trimethylammonium chloride, which is non-volatile, resistant to air and does not leak regardless of ambient temperature. Make sure to keep it away from any source of ammonia or other alkali/bases.
Disposal
Trimethylamine should be diluted in water and neutralized with a non-toxic acid. As it's not hazardous to the environment, it can be further diluted and poured into the ground.
References
- ↑ Van Gysel, August B.; Musin, Willy (2000). "Methylamines". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH
- ↑ http://www.orgsyn.org/demo.aspx?prep=CV1P0528
