Draw all geometrical and linkage isomers of square planar \(\left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2}(\mathrm{SCN})_{2}\right]\).

We have two possible geometrical arrangements for the ligands in a square planar complex: cis and trans. 1. Cis arrangement: Both NH3 ligands are adjacent, and both SCN- ligands are adjacent. \(\begin{array}{cc} \left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2}\left(\mathrm{SCN}\right)_{2}\right]_{\text {cis }} \end{array}\) 2. Trans arrangement: Both NH3 ligands are opposite, and both SCN- ligands are opposite. \(\begin{array}{cc} \left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2}\left(\mathrm{SCN}\right)_{2}\right]_{\text {trans }} \end{array}\)

Now we will draw the possible linkage isomers by considering the SCN- ligand binding through either the sulfur (S) or the nitrogen (N) atom. 1. Cis arrangement (N-bonded SCN-): \(\begin{array}{cc} \left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2}\left(\mathrm{NCS}\right)_{2}\right]_{\text {cis}} \end{array}\) 2. Cis arrangement (S-bonded SCN-): \(\begin{array}{cc} \left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2}\left(\mathrm{SCN}\right)_{2}\right]_{\text {cis}} \end{array}\) 3. Trans arrangement (N-bonded SCN-): \(\begin{array}{cc} \left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2}\left(\mathrm{NCS}\right)_{2}\right]_{\text {trans}} \end{array}\) 4. Trans arrangement (S-bonded SCN-): \(\begin{array}{cc} \left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2}\left(\mathrm{SCN}\right)_{2}\right]_{\text {trans}} \end{array}\) Therefore, there are four possible isomers for the given complex: two geometrical isomers and two linkage isomers.