Delocalization energy, definition estimation

Acids and bases can also be considered from another point of view. In this view acids are electron acceptors while bases are electron donors. Lewis has used this definition to extend the concept of acidity and basicity to the compounds which don t have hydrogen. The molecule of amine is a stronger base if the electron lone pair on nitrogen is more localized. Localization or delocalization can be estimated by writing the appropriate resonance structures. Electrons are localized if only one resonance formula can be drawn. In principle, if the electron pair is delocalized over a large part of the molecule, the electron energy is lower, the system is more stable and does not require the addition of a proton. 

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