MOLECULAR ORBITAL THEORY
MOLECULAR ORBITAL THEORY Molecular orbital (MO) theory was developed by F. Hund and R.S. Mulliken in 1932
Linear combination of atomic orbital's (LCAO) ψMO = ψA + ψB σ and σ* are formed as : σ = ψA + ψB ( Bonding MO) σ* = ψA – ψB ( Anti bonding MO )
Conditions for the Combination of Atomic Orbitals Same energy. Same symmetry Must overlap to the maximum extent
TYPES OF MO ORBITALS σ (sigma), π (pi), δ (delta)
sigma (σ) molecular orbitals are symmetrical around the bond-axis pi (π) molecular orbitals are not symmetrical
Energy of the MO Orbitals for O2 and F2 Energy of the MO Orbitals for Other molecules
MO ELECTRONIC CONFIGURATION FOR H2 Number of Electrons = 2
MO ELECTRONIC CONFIGURATION FOR He2 NUMBER OF ELECTRONS = 4 Bond order of He2 is ½(2 – 2) = 0
Lithium molecule Li2 No. of Electrons = 6
CARBON MOLECULE C2 No Of Electrons = 12
N2 MOLECULE
Oxygen molecule (O2 )
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