Characteristic features of π-bonds are as follows:
(i) π-bonds is formed by sideways or lateral over-lapping of parallel π-orbitals.
(ii) In CH2 = CH2 molecule, all the atoms must be in same plane.
(iii) The p-orbitals. Should be parallel and perpendicular to the plane of molecule.
(iv) Rotation around one CH2 fragment with respect to other interferes with maximum overlap of p-orbitals and therefore, such rotatioe of C=C is restricted, which leads to formation of geometrical isomers i.e., cis trans isomers in alkenes e.g.,
Cis-2 Butene
trans-2 Butene
