Question

What are coordination isomers? Give an example.

Answer 1

Hint: We know that coordination isomerism is a form of structural isomerism in which the composition of the coordination complex ion varies. In a coordination isomer the total ration to ligand to metal remains the same, but the ligands attached to a specific metal ion change. Examples of a complete series of coordination isomers require at least two metal ions and sometimes more.

Complete answer:
We have to remember that the coordination complex is a compound that has a central atom( ion) that is metallic and is known as a coordination centre.
So coordination isomers are two or more coordination of compounds in which the composition inside the coordination sphere i.e. the metal atom and the ligands that are attached to it is different, that is connectivity between atoms are different.
Some examples of pairs of coordination isomers are:-
$Co{(N{H_3})_6}^{3 + }Cr{(CN)^{3 - }}_6$ and $Cr{(N{H_3})_6}^{3 + }Co{(CN)_4}^{3 - }$
$Zn{(N{H_3})_4}^{2 + }CuC{l_4}^{2 - }$ and $Cu{(N{H_3})_4}^{2 + }ZnC{l_4}^{2 - }$
Hence above these are the examples of coordination isomers.

Note:
We should know the other possible isomers in coordination compounds. Some other possible isomers are hydrate isomerism, linkage isomerism, ionization isomerism. We know that the compounds with identical molecular formula but differ in the arrangement of the atom are said to be isomers.