Question

Explain coordination and ionisation isomerism with suitable examples?

Answer 1

Hint: In the given question firstly we have to define exactly these kinds of isomers and then we can give the proper definition and the examples of it. Although we know that the main points among the following is that we should have the chemical formula the same.

Complete step by step answer:
The given question statement asks about the entire process through which we would be able to get the proper and correct explanation of the coordination and ionisation isomerism and the suitable examples. So we have to explain what exactly are the processes of this kind of isomerism and the adequate examples for it.
Coordination isomerism:
In this type of isomerism the Ligands are interchanged between the cationic and the anionic entities of different metal ions which are present in the complex. The isomers must have the same molecular formula.
For example, we can say that in the coordinate compound of \[[Co{(N{H_3})_6}][Cr{(CN)_6}]\] the molecule of ammonia ligands are bound to Co and cyano ligands are bound to Cr. Whereas in the the coordinate compound of \[[Co{(N{H_3})_6}][Cr{(CN)_6}]\] , ammonia ligands are bound to Cr and cyano ligands are bound to Co.
Ionisation isomerism ( ion-ion exchange isomerism ):
In this type of isomerism There is exchange of ions inside and outside the coordination sphere. The isomers have the same molecular formula but produce different ions in solution.
Example: Red violet colored \[[Co{(N{H_3})_5}S{O_4}]Br\] produces \[{[Co{(N{H_3})_5}S{O_4}]^ + } + B{r^ - }\] ions in the solution whereas we can get the red colored \[[Co{(N{H_3})_5}Br]S{O_4}\] produces the mixture of \[{[Co{(N{H_3})_5}Br]^{2 + }} + S{O_4}^{2 - }\] ions in the given solution.

Note: Isomerism was first observed in 1827, when Friedrich Wöhler prepared silver cyanate and discovered that, although its elemental composition of AgCNO was identical to silver fulminate (prepared by Justus von Liebig the previous year), its properties were distinct. This finding challenged the prevailing chemical understanding of the time.