The (en) in a chemical formula or ligand stands for ethylenediamine, which is a bidentate ligand commonly used in coordination chemistry. This means that it can bind to a metal ion through two donor sites.
Ethylenediamine is usually represented as a two-letter abbreviation, en, within parentheses in a chemical formula, such as [Co(en)3]Cl3. It can also be written as H2NCH2CH2NH2.
Ethylenediamine is a colorless, hygroscopic liquid with a strong ammonia-like odor. It has a molecular formula of C2H8N2 and a molar mass of 60.10 g/mol. It is highly soluble in water and polar solvents, and it can form stable complexes with metal ions.
Ethylenediamine is commonly used as a ligand in coordination chemistry, where it forms complexes with metal ions. It is also used as a building block in organic synthesis, particularly in the production of nylon. It has various other industrial applications, such as in the production of pesticides and pharmaceuticals.
Ethylenediamine is a corrosive and toxic substance, and proper precautions should be taken when handling it. It can cause severe skin and eye irritation, and inhalation of its vapors can lead to respiratory issues. It is important to use protective equipment, such as gloves and safety glasses, when working with ethylenediamine.