Question

One of the most important properties of `d`-block metal cations is the formation of coordinate compounds. Widely used theories that explain bonding in these compounds are valence bond theory and crystal field theory.
The incorrect option for the complex compounds $\left[Co\left(SCN\right){\left(H_{2}O\right)}_5\right]{\left(N{O}_3\right)}_2\text{and}\left[Co\left(N{O}_3\right){\left(H_{2}O\right)}_5\right]\left(SCN\right)\left(N{O}_3\right)$ is:

• A. Both are ionization isomers
• B. They can exhibit hydrate isomerism
• C. They can exhibit linkage isomerism
• D. They do not show stereoisomerism

Answer 1

The correct option is C They can exhibit linkage isomerism

It is pretty clearly understood that both the complexes have the same molecular formula but show a difference in arrangement. Hence, we can call them isomers.
As we can see, the ligands have been interchanged between the coordination and ionization spheres and hence we can call them ionization isomers.
There is also a possibility of changing the number of water ligands inside and outside the coordination sphere. Hence, we can say that it will also display hydrate isomerism.
However, when it comes to linkage isomer, we can see that $SC{N}^{-}$ is not inside the coordination sphere of the complex and hence it will not behave as a ligand. Thus, we can say that the second complex is not capable of showing linkage isomerism due to the absence of an ambidentate ligand in the coordination sphere.
Since there are 5 identical ligands inside the coordination sphere, it will not show stereoisomerism.