Ethylenediamine

Ethylenediamine is an organic compound with the formula C₂H₄(NH₂)₂, and is often abbreviated en when used as a ligand. It is a common ligand in coordination chemistry and a ubiquitous chemical building block in organic synthesis. It is volatile, but tends to form a mist in air, which is quite toxic.

Properties

Physical properties

Ethylenediamine is a clear, colorless liquid at room temperature. It freezes at 8 °C and boils at 116 °C, both of which are close to the melting and boiling points of water. It has an ammoniacal smell, and its vapors are extremely irritating. It is miscible with water at all concentrations.

Chemical properties

Ethylenediamine is a powerful chelating agent and will readily complex to many metal ions, notably, cobalt, nickel, copper, and chromium (with some difficulty). The stability of these complexes is due to an increase in entropy by freeing 2 monodentate ligands per complexed ethylenediamine molecule.

Energetic materials can be made with ethylenediamine and metal perchlorates, most notably tris(ethylenediamine)nickel perchlorate and bis(ethylenediamine)copper(II) perchlorate.

Availability

Ethylenediamine is sold by chemical suppliers.

Preparation

Ethylenediamine is manufactured industrially by reacting 1,2-dichloroethane with ammonia under pressure, at 180 °C in an aqueous medium. This process is complex for the amateur chemist.

Projects

• EDTA synthesis
• Make various complexes
• Make tris(ethylenediamine)nickel perchlorate
• Make ethylenediamine dinitrate

Handling

Safety

Ethylenediamine is toxic and has serious adverse health effects when inhaled. As a pure liquid, it will vaporize and form a mist in the air. If pure ethylenediamine must be used, it should be handled in a fume hood. Otherwise, it is preferable to use a 20% solution, which does not emit fumes and still allows for complexation.

Storage

Should be stored in closed bottles, and sealed to prevent the smell from leaking.

Disposal

Ethylenediamine can be burned.