JEE Main 2024 — Coordination Compounds Question with Solution

Ambidentate ligands are ligands that can attach to a central metal atom through two different atoms. Let’s analyze the given ligands one by one:

• $${\mathrm{NO}}_2^{-}$$: This ligand can bind through either the nitrogen (N) or the oxygen (O). Therefore, $${\mathrm{NO}}_2^{-}$$ is an ambidentate ligand.
• $${\mathrm{SCN}}^{-}$$: This ligand can bind through either the sulfur (S) or the nitrogen (N). Therefore, $${\mathrm{SCN}}^{-}$$ is an ambidentate ligand.
• $${\mathrm{C}}_2{\mathrm{O}}_4^{2-}$$ (oxalate): This is a bidentate ligand, but it coordinates through both oxygen atoms only. Therefore, it is not an ambidentate ligand.
• $${\mathrm{NH}}_3$$: This ligand can only bind through nitrogen (N). Therefore, it is not an ambidentate ligand.
• $${\mathrm{CN}}^{-}$$: This ligand can bind through either carbon (C) or nitrogen (N). Therefore, $${\mathrm{CN}}^{-}$$ is an ambidentate ligand.
• $${\mathrm{SO}}_4^{2-}$$ (sulfate): This ligand typically coordinates through oxygen atoms. It is not considered an ambidentate ligand.
• $${\mathrm{H}}_2\mathrm{O}$$: This ligand can only bind through oxygen (O). Therefore, it is not an ambidentate ligand.

Based on this analysis, the ambidentate ligands are $${\mathrm{NO}}_2^{-}$$, $${\mathrm{SCN}}^{-}$$, and $${\mathrm{CN}}^{-}$$.

Therefore, the number of ambidentate ligands among the given options is 3.