Using molecular orbital theory,

Question:
Using molecular orbital theory, compare the bond energy and magnetic character of O2+ and O2- species.

Solution:

The Molecular Orbital configuration of O2+ and O-2 is given below:

O2+ (15): σ1s2 σ *1s2 σ 2s2 σ *2s2 σ 2pz2 π2px2 = π 2py2π *2px1

O2- (17): σ1s2 σ *1s2 σ 2s2 σ *2s2 σ 2pz2 π2px2 = π 2py2π *2px2= π*2py1

Bond order for O2+ = 10-5/2 = 2.5

Bond order for O-2 = 10-7/2 = 1.5

According to Molecular Orbital Theory, the greater the bond order greater is the bond energy.

Thus, O2+ is more stable than O2-