Question

What is meant by unidentate, didentate and ambidentate ligands? Give two examples for each.

Answer 1

Unidentate ligand:
Only one donor site is present. Examples includes ammonia and chloride ions.
Bidentate ligand:
Two donor sites are present. Examples include ethylene diammine and oxalate ion
Ambidentate ligand:
Ligands can coordinate to a central metal through two different sites.
Examples include (1) nitro group ($N$ as donor atom) and nitrito group ($O$ as donor atom)
(2) Thiocyanate ($S$ atom as donor atom) and isothiocyanate ($N$ atom as donor atom).