Question

Find the rate of geometrical isomers in $[M{{(AA)}_{2}}{{b}_{2}}]$ and optical isomers of $[M{{(AA)}_{3}}]$
a.) 1
b.) 2
c.) 1.5
d.) 2.5

Answer 1

Hint: To write the geometrical isomerism we have to identify the bonding connectivity between atoms. The molecules having the same bonding connectivity can be a geometrical isomer. Optical isomers are the molecules which differ from each other in their behaviour towards the plane-polarized light.

Complete step by step answer:
- The stereoisomers are defined as the molecules have the same bonding connectivity and different molecular configuration. Stereoisomers are of two type’s i.e. optical and geometrical isomers.
- Geometrical isomers are the isomers which differ by the arrangement along the double bond ring and other rigid structure. Optical isomers are the molecules which differ from each other in their behaviour towards the plane-polarized light. They have the different arrangements of the same atoms or groups in a molecule.
- The complex $[M{{(AA)}_{2}}{{b}_{2}}]$ has 2 geometrical isomers i.e. cis and trans and the complex $[M{{(AA)}_{3}}]$ also has two optical isomers i.e. d and l.
Hence, the ratio is = $\dfrac{2}{2}=1$ The correct option is option “A” .

Additional Information .
- Optical isomers are the molecules which differ from each other in their behaviour towards the plane-polarized light. They have the different arrangements of the same atoms or groups in a molecule.
- Enantiomers are defined as the stereoisomers of a compound which have non superimposable mirror images. They have identical physical properties, the enantiomer which rotates the plane polarized light to the left is known as laevo rotatory and the enantiomer which rotates the plane polarized light to the right is known as dextrorotatory.

Note: While identifying the geometrical isomers it is important to restrict the rotation of the carbon-carbon double bond. A main criterion of having geometrical isomerism is to have different groups attached to the carbon atoms.