Monodentate

A monodentate ligand is a ligand which forms only one bond with the central atom, usually a metal ion. A monodentate ligand is also sometimes called a "unidentate ligand" from the root words meaning "one tooth". A monodentate ligand, like other types of ligands, can be a neutral molecule or an ion with a lone pair.

Some examples of common monodentate ligands that are neutral molecules are H2O (aqua), NH3 (ammine), CH3NH2 (methylamine), CO (carbonyl), and NO (nitrosyl).

Some examples of common monodentate ligands that are anions are F- (fluoro), CN- (cyano), Cl- (chloro), Br- (bromo), I- (iodo), NO2- (nitro), and OH- (hydroxo).

The hexacyanoferrate(II) ion, [Fe(CN)6]4-, contains 6 monodentate cyanide (CN-) ligands attached to the central iron atom.