Question

What is Gauche effect​

Answer 1

The term "gauche" refers to conformational isomers where two vicinal groups are separated by a torsion angle of 60°. IUPAC defines groups as gauche if they have a "synclinal alignment of groups attached to adjacent atoms". In stereochemistry, gauche interactions hinder bond rotation.

Answer 2

Hey Mate

The gauche effect is commonly explained with LCAO-based bond orbitals. LCAO is short for linear combination of atomic orbitals and implies that we can take two atomic orbitals ϕ1,ϕ2 and create two molecular orbitals ψ1,ψ2 from them by linear combination: ψ1=a1ϕ1+b1ϕ2 and ψ2=a2ϕ1+b2ϕ2.

hope it helps you