Bond order=1/2(bonding−anti-bonding)
According to molecular orbital diagram, the bond order of CO+ is 3.5
The highest occupied molecular orbital is sigma*2s MO
In the case oc CO, the 2s atomic orbital on oxygen is much lower than the energy than the 2s atomic orbital of carbon
This discrepancy of energy allows the pi2px & pi2py BMO to lower the energy than sigma*2sMO in the MO diagram of CO
Bond order of CO+ = 1/2 [Nb – Na]
= 1/2 [10 – 3 ]
= 3.5
This is according to Molecular Bond Diagram
