The ligands are the atoms of molecules that offer electrons and the central metal atom is the species to which the ligand provides the electrons.
The core metal atom will be an electron-poor species, whereas the ligands will be electron-rich.
The amount of donor atoms present in a ligand determines its classification.
Unidentate is a species that may create a coordination bond with only one donor atom. These ligands will only have one donation site accessible.
Bidentate ligands are species having two donor sites that can coordinate with the central metal atom to create the coordinate bond.
Ambidentate ligands are ligand species in which the donor species tends to bind with the central metal atom via two distinct locations.
Final Answer:
Unidentified ligand indicates there is just one donation location. Ammonia and chloride ions are two examples.
Bidentate ligand indicates the presence of two donor sites.
Ethylene diammine and oxalate ion are two E.g.
Ambidentate ligands are those that can coordinate to a central metal via two distinct locations.
(1) Nitro group (N as donor atom) and nitrito group (O as donor atom) are two e.g.
(2) Thiocyanate (donor atom S) and isothiocyanate (N atom as donor atom).