Conformation Analysis

 

Conformers are abserved due to free rotation arround sigma bond. There are infinite Conformation of a compound, and specific Conformation of a compound known as conformers.

> Conformers are stable Conformation of a compound.

Conformation of Ethane :—

[CH3 - CH3] 

Conformation of Propane :-

CH3 - CH2 - CH3  ये Identical है, लेकिन अलग - अलग होंगे तो ये बताना होगा कि किस C के Along Rotate होगा। 

Conformation Of Butane :-

Stability Order :-

Anti Staggered > Gawche > Partially > Fully Eclipsed.

Conformation are stable due to 

1. Torsional Strain

2. Steric Strain (Vander waal Strain)

Torsional Strain :-

Is due to Dihedral Angle. 

Is due to Bond - Pair - Bondpair repultison. 

Less Dihedral angle more will be the Torsional Strain.

Vander Waal Strain :-

Due to Repulsion of bulky group. 

** Nett Repulsive Energy for Diss. Eclipse & Gawche Form. **

(1) H - H are Eclipsed to each other then nett repulsive energy is 1Kcal/mol.

(2) If CH3 - CH3 are Gouche To each other then nett repulsive energy is 0.9Kcal/mol.

(3) If CH3 - H are Eclipsed to each other then nett repulsive energy is 1.5Kcal.

(4) CH3 - CH3 are Eclipsed to each other then nett repulsive energy is 4Kcal.

Higher the Repulsive Energy less will be Stability. 

Watch This Video For Detailed conceptual Explanation.