Calculating Number of Geometrical Isomers

Definition of Geometrical Isomers
Geometrical isomers are a type of stereoisomer that differ in the spatial arrangement of atoms due to restricted rotation around a bond.

Factors Affecting Geometrical Isomerism
- Presence of double bonds or rings in the molecule
- Different groups attached to the double bond or ring
- Steric hindrance preventing free rotation

Rules for Calculating Geometrical Isomers
1. Identify the number of double bonds or rings in the molecule.
2. Determine the different groups attached to the double bond or ring.
3. Consider the arrangement of these groups in space to determine isomers.

Formula for Calculating Geometrical Isomers
The formula to calculate the number of geometrical isomers for a compound with 'n' number of double bonds is:
2^n

Example
For a compound with 2 double bonds, the number of geometrical isomers would be:
2^2 = 4 isomers

Conclusion
Calculating the number of geometrical isomers involves understanding the structure of the molecule, identifying the factors that lead to isomerism, and applying the formula based on the number of double bonds or rings present in the compound.