THE INTERACTION OF FRIEDEL–CRAFTS CATALYSTS WITH ORGANIC MOLECULES: I. THE CH₃COCl:AlCl₃ SYSTEM

Abstract

An infrared study of the liquid complex of aluminum chloride with acetyl chloride has been undertaken. The results indicate that the pure liquid complex is not a simple mixture, but consists of (1) the donor–acceptor complex [Formula: see text] and (2) the ions [CH 3 CO] + and [AlCl 4 ] − . A solution of the liquid complex in a solvent of high dielectric constant like nitrobenzene (ε = 36.1) contains both these species, but in a low dielectric constant solvent like chloroform (ε = 5.05) only (1) is present. The carbon–chlorine bond in (1) is modified. The mechanism of Friedel–Crafts ketone synthesis is briefly examined in the light of these results.