chemistry

DIFFERENCE BETWEEN PI AND SIGMA BOND

			( σ) Sigma bond	(π) Pi BOND
	1)	It is a strong covalent bond formed by		It is a weak covalent bond formed by the side
		over lapping along internuclear axis.		wise or lateral overlapping
	2)	It involves head on (or) end – on – end		It involves lateral and sidewise overlapping above
		overlapping.		and below the axis.
	3)	The  bonding  electron  density  is		Pi electron density lies above and below the axes.
		symmetrical and lies along the axis
	4)	Sigma bond is formed by overlapping of		It is formed by the overlapping of p – p or p – d
		any two half filled orbitals		orbitals.

		(s - s, s - p, p - p)
	5)	It can be formed by pure valence	It is formed by only pure valence orbitals.
		orbitals or hybrid orbitals.
	6)	If s orbital is involved in overlapping,	If p-orbital is involved in overlapping, it may be
		the bond formed is always sigma.	sigma or pi
	7)	The first formed bond between two	It is formed only after the formation of sigma
		atoms is always sigma bond. Sigma has	bond. It has no Independent existence
		Independent existence
	8)	It determines the geometry of molecules	It has no role in determining geometry of molecules.
	9)	One of the two lobes is involved in over	Both the lobes of p - orbital are involved in bond
		lapping	formation
	10) Free rotation of orbitals is possible		Free rotation of orbitals is restricted