Number of ambidentate ligands in a representative metal complex $\left[\mathrm{M}(\mathrm{en})(\mathrm{SCN})_{4}\right]$ is ___________.

[en = ethylenediamine]

<p>Ambidentate ligands are ligands that can bond to a metal atom through two different atoms. They can attach through one site or the other, but not both at the same time.</p> <p>In the given complex $[\mathrm{M}(\mathrm{en})(\mathrm{SCN})_{4}]$:</p> <ul> <li><p>$\mathrm{en}$, or ethylenediamine, is a bidentate ligand, meaning it can form two bonds with the metal ion, but it is not ambidentate because it always binds through the same two nitrogen atoms.</p> </li> <li><p>$\mathrm{SCN}^{-}$, on the other hand, is an example of an ambidentate ligand. It can bind to the metal either through the sulfur atom ($\mathrm{S}$) or the nitrogen atom ($\mathrm{N}$).</p> </li> </ul> <p>Since there are four $\mathrm{SCN}^{-}$ ligands in the given complex, the number of ambidentate ligands is 4.</p>