Exchange of halogens between aromatic compounds in the presence of Cu-HZSM-5 zeolite

Abstract The reactions between various haloaromatics in binary mixtures which were approximately equimolar, were studied in gas-phase (673 K, atmospheric pressure) in the presence of a 2 wt % Cu-HZSM-5 zeolite. The exchange of halogens (ipso substitution) between the two compounds was assumed to occur either through a radical mechanism involving an electron transfer between an atom of copper (I) and one aromatic molecule or through a nucleophilic substitution involving arylcopper complexes as intermediates.