Benzene will react with halogens in the presence of a halogen carrier. For the bromination of benzene FeBr3 or AlBr3 is used. For the chlorination of benzene, FeCl3 or AlCl3 can be used as a halogen carrier.Iron metal can also be used as it reacts with any chlorine or bromine present to form the iron (III) halide. Chlorine reacts with benzene in the presence of a halogen carrier at room temperature and pressure.The electrophile accepts a pair of electrons from the electron dense ring and forms a covalent bond. This intermediate is unstable as the delocalised ring is disrupted and loses a H+ ion to restore the stability.