Question

How many total isomers for $ \left[ Co{{\left( en \right)}_{2}}C{{l}_{2}} \right]N{{O}_{2}} $ ?

Answer 1

Hint: We know that the given complex has stereoisomers and it does not have structural isomers. One of the isomers of this complex can rotate the plane of the polarized light. Configurational isomers are the stereoisomers that cannot be converted into one another by rotation around a single bond in the molecule.

Complete answer:
Isomers are the species which have the same molecular formula but different properties. Isomers can be divided into two main categories: structural isomers and stereoisomers. Structural isomerism can also be divided into categories like linkage isomerism, coordination isomerism, ionization isomerism and solvate isomerism. There are two types of Configurational isomers:
-Geometrical Isomers
-Optical Isomers.
Geometrical isomerism is going to show by unsaturated compounds and optical isomerism is going to exhibit by the molecules that are having chiral carbons.

The given compound will have two geometric isomers; cis and trans. Optical isomers are the mirror images of the compounds that cannot be superimposed on each other. So, the cis isomer can form such two isomers (including itself) that are enantiomers. The optical isomers are named as dextro and laevo depending upon its characteristic to rotate the plane polarized light.
Therefore, the total isomers for $ \left[ Co{{\left( en \right)}_{2}}C{{l}_{2}} \right]N{{O}_{2}} $ are $ 3. $

Note:
Remember that don’t be confused between geometrical isomerism and optical isomerism. The compounds that have double bonds will show geometrical isomerism and the compounds which have chiral centers show the optical isomerism.