Ligand: In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex.
- EDTA (ethylenediaminetetraacetic acid) has six donors.
- The formula of it is not very simple to get if you know the name of the elements in it. It forms from 10 carbon atoms, 16 hydrogen atoms, 2 nitrogen atoms, and 8 oxygen atoms. In this way, its chemical formula is C10H16N2O8.
- The structure of EDTA showing six donor sites, i.e., two nitrogen atoms and four oxygen atoms is given below.
Hence, EDTA is a hexadentate ligand.