Localized and Delocalized Bonding
To understand the localized and delocalized bonding, we should know about chemical bond. A chemical bond is formed by the connection between two atoms. It occurs due to the overlapping of molecular orbitals. There are basically two major types of bonds; Localized and delocalized chemical bonds.
Localized Chemical Bond
The bonds in which the overlapping orbitals are almost in fixed positions are said to be localized bonds. The electronic charge is not distributed in atoms or molecules. They are normal sigma and pi bonds or lone electron pairs that exist on a single atom. Localized bonds electron density is concentrated on a limited region, so only that specific region contains the high electron density. Localized bonds form with the overlap of two s-orbitals, two p-orbitals or s-p overlap. They are less stable.
Delocalized Chemical Bond
The bonds in which the overlapping orbitals are not fixed are said to be delocalized bonds. The electronic charge is distributed due to the resonance in atoms or molecules. The delocalized bonds do not associate with only a single atom but with several atoms or other chemical bonds and electrons in these bonds are called as delocalized electrons. Delocalization arises in the conjugated systems, which contain double bonds and single bonds in an alternating system.
For example, 1,3-butadiene contain conjugated system.