The substitution pattern of functional groups on aromatic compounds, such as benzene rings, can significantly affect their reactivity and properties. This is due to the electronic and steric effects of the substituents, which can either activate or deactivate the aromatic ring towards electrophilic aromatic substitution reactions. Additionally, the position of the substituent on the ring can direct the incoming electrophile to ortho, meta, or para positions.1. Electronic effects: Substituents can be classified as electron-donating groups EDGs or electron-withdrawing groups EWGs based on their inductive or resonance effects on the aromatic ring.- Electron-donating groups EDGs : These groups, such as alkyl groups and hydroxyl groups, donate electron density to the aromatic ring through inductive or resonance effects. This increases the electron density of the ring, making it more nucleophilic and more reactive towards electrophilic aromatic substitution reactions. EDGs generally activate the aromatic ring and direct the incoming electrophile to ortho and para positions.- Electron-withdrawing groups EWGs : These groups, such as nitro, carbonyl, and halogen groups, withdraw electron density from the aromatic ring through inductive or resonance effects. This decreases the electron density of the ring, making it less nucleophilic and less reactive towards electrophilic aromatic substitution reactions. EWGs generally deactivate the aromatic ring and direct the incoming electrophile to the meta position.2. Steric effects: The size and shape of the substituent can also affect the reactivity and properties of aromatic compounds. Bulky substituents can hinder the approach of electrophiles, making the reaction slower. Additionally, steric effects can influence the regioselectivity of the reaction, favoring the formation of products where the incoming electrophile is positioned further away from the bulky substituent.In summary, the substitution pattern of functional groups on aromatic compounds can greatly influence their reactivity and properties due to electronic and steric effects. Understanding these effects is crucial for predicting the outcome of electrophilic aromatic substitution reactions and designing efficient synthetic routes for the preparation of various aromatic compounds.