Here are the essential concepts you must grasp in order to answer the question correctly.
Electrophilic Aromatic Substitution (EAS)
Electrophilic Aromatic Substitution is a fundamental reaction in organic chemistry where an electrophile replaces a hydrogen atom on an aromatic ring. The reactivity of the aromatic compound in EAS is influenced by the nature of substituents already present on the ring, which can either donate or withdraw electron density, affecting the stability of the intermediate carbocation formed during the reaction.
Recommended video:
Electron-Withdrawing and Electron-Donating Groups
Substituents on an aromatic ring can be classified as electron-withdrawing or electron-donating. Electron-withdrawing groups, like fluorine, decrease electron density on the ring, making it less reactive towards electrophiles. Conversely, electron-donating groups, such as alkyl groups, increase electron density, enhancing reactivity in EAS. The balance of these effects determines the overall reactivity of substituted aromatic compounds.
Recommended video:
Donating vs Withdrawing Groups
Halogen Substituents and Their Reactivity
Halogen substituents, such as fluorine and chlorine, exhibit unique reactivity patterns in aromatic compounds. While both are electron-withdrawing, fluorine is more electronegative and exerts a stronger withdrawing effect, making fluorobenzene less reactive than chlorobenzene in EAS. In contrast, when considering alkyl-substituted derivatives like chloromethylbenzene and fluoromethylbenzene, the presence of the alkyl group can enhance reactivity, leading to different outcomes based on the halogen's influence.
Recommended video: