Benzene reacts with chlorine in the presence of an iron catalyst to produce

Benzene reacts with chlorine in the presence of an iron catalyst (typically iron(III) chloride, FeCl3) to produce chlorobenzene through a mechanism known as electrophilic aromatic substitution [t1][t2]. In this process, the iron catalyst acts as a Lewis acid that activates the chlorine molecule (Cl2) to form a highly reactive chloronium ion (Cl+) [t3]. This electrophile then attacks the electron-rich benzene ring, forming an unstable sigma complex or arenium ion [t3][t4]. To restore the stable aromaticity of the ring, the complex loses a proton (H+), resulting in the final product, chlorobenzene [t3]. While benzene hexachloride can be formed via addition under UV light and benzyl chloride is typically formed from toluene, the specific use of an iron catalyst facilitates the substitution of a hydrogen atom on the benzene ring with a chlorine atom [t2][t5].