What Is Tetramethylethylenediamine?

Tetramethylethylenediamine (TEMED or TMEDA) is a complex compound made from ethylenediamine by replacing four groups with four other groups. This compound is used frequently as a ligand, or binding compound that binds with metal to make a coordination complex, and as a catalyst to polymerize polyacrylamide gel. At room temperature, tetramethylethylenediamine is a liquid, and it has a boiling point similar to that of water; its odor is fishy. While tetramethylethylenediamine is stable, it can easily catch fire and is incompatible with several compounds, such as oxidizing agents and acids.

Tetramethylethylenediamine is a chemically complex compound made primarily of carbon and hydrogen, with some nitrogen. This compound is formed by first creating ethylenediamine, another hydrocarbon. After the ethylenediamine is made, four of the nitrogen-hydrogen groups are removed and replaced with nitrogen-methyl groups. Its molecular weight is 116.20, making it a fairly heavy compound.

This compound is used frequently in manufacturing plants as a ligand for metal ions, especially lithium. A ligand is a molecule that latches onto the central atom in the metal and creates a coordination complex. In a molecular sense, this causes the metal ion to expand and become stronger. Tetramethylethylenediamine also is used in the polymerization process to create acrylamide and polyacrylamide gels. These gels are used in research to help move molecules around and to separate protein fragments.

When it comes to the physical properties of tetramethylethylenediamine, it is a colorless liquid that smells powerfully of fish. Its melting point is close to water, at 248° Fahrenheit (120° Celsius), and it is quite dense as a vapor. At room temperature, TEMDA is a liquid, and it can combine with other liquids, because it is soluble. It has a high acid rating and can be a health hazard if it touches skin, is ingested or gets in the lungs or eyes. If TEMDA is physically encountered without protection, then medical attention should be sought immediately.

While tetramethylethylenediamine is a very stable compound and will not react to most other chemicals, it has many storage risks. The largest risk is that TEMDA is highly flammable, so it comes with a red label, meaning it should not be stored at high temperatures or around equipment that can heat up. It also is incompatible with acids and acid chlorides, oxidizing agents, mercury and copper, so it should not be stored near any of these elements or compounds, just to ensure safety.