Using MO theory, explain why cyclobutadiene is antiaromatic. Strategy: Use the polygon-and-circle method for deriving the relative energies pi MOs.

Using MO theory, explain why cyclobutadiene is antiaromatic. Strategy

1.	Using MO theory, explain why cyclobutadiene is antiaromatic. Strategy: Use the polygon-and-circle method for deriving the relative energies pi MOs.
Answer» Solution : The MO ELECTRON DISTRIBUTION is Since the nonbonding `MOs` are half-filled, CYCLOBUTADIENE isantiaromatic.