Ethylenediaminetetraacetate ion (EDTA
4–) is
an important hexadentate ligand It can bind through two
nitrogen and four oxygen atoms to a central metal ion When a di- or polydentate ligand uses its two or more donor
atoms simultaneously to bind a single metal ion, it is said to be a
chelate ligand The number of such ligating groups is called the
denticity of the ligand