Question

An ambidentate ligand is one which is:
A.Can be linked to central metal atom from two sides
B.Has two donor atoms but only one of them has the capacity to form a coordinate bond
C.Has two donor atoms and either of the two can form a coordinate bond
D.Forms chelate rings

Answer 1

A Coordination compound is a compound in which a metal cation is attached to a group of ligands by coordinate bonds. A species that has at least one lone pair of electrons to a metal cation is known as ligands.

Complete step by step answer:
-An ambidentate ligand is a monodentate ligand having two or more donor atoms and which can coordinate to the central metal atom through either of the two different donor atoms.
-Depending upon the number of ligand donor atoms attached to the metal cation, ligands can be classified into monodentate or polydentate ligands.
An Ambidentate ligand is a monodentate ligand. Monodentate ligand is a ligand which shares the electron pair of a single donor atom with a metal atom. A monodentate ligand binds to the central metal atom with one lone pair of electrons. Denticity of a ligand is the number of pairs of electrons shared with the metal atom. Therefore, Denticity of a monodentate ligand is one. Examples include ${F^ - }$ , $C{l^ - }$ , $C{N^ - }$ , $CH3CO{O^ - }$ , $O{H^ - }$ , ${H^ - }$ .
A monodentate ligand which has two or more donor atoms can coordinate to a metal cation through either of the two different atoms. This type of monodentate ligands are known as Ambidentate ligands. This ligand when coordinated to a metal cation through either of the two donor atoms, two different compounds are formed which are called Linkage isomers. Examples for ambidentate ligands are $- SC{N^ - }$ , $- NO{2^ - }$ , CO, $C{N^ - }$ , $S{O_3}^{2 - }$ .
For Example, SCN- can coordinate to the metal by either S or N.
M- SCN- M- $SC{N^ - }$
Sulphur atom of SCN- coordinate with the metal Nitrogen atom of $SC{N^ - }$ coordinate with the metal

Hence, the correct answer is (C) i.e Has two donor atoms and either of the two can form a coordinate bond.

Note:
Ambidentate ligand forms linkage isomers. But except $- N{O_2} -$ , $S_{2}O_{3}^2-$ , $- SC{N^ - }$ none of these has yet formed linkage isomers.