A STUDY OF SOME FACTORS INFLUENCING THE ACTIVITY OF ALUMINUM AND FERRIC CHLORIDES IN THE FRIEDEL AND CRAFTS REACTION

Abstract

In the preparation of aluminum chloride by the action of hydrogen chloride on the metal, hydrogen chloride is adsorbed and can be recovered to the extent of about 9 cc. per gram. After sublimation in nitrogen and re-sublimation in hydrogen chloride, however, the amount of adsorption is smaller and irregular. The adsorbed gas is not removed by a stream of nitrogen at room temperature. The activities in the Friedel and Crafts reaction of various preparations of aluminum chloride and of ferric chloride and of mixtures of these were determined; the order of decreasing activity was found to be as follows: a mixture of aluminum chloride and ferric chloride, aluminum chloride made by the action of hydrogen chloride on aluminum, aluminum chloride made by the action of chlorine on aluminum, a mixture of aluminum chloride and partially reduced ferric chloride, ferric chloride, and partially reduced ferric chloride. The most striking result of the measurements is that although ferric chloride alone has an activity of only about one-third that of aluminum chloride, an approximately equimolecular mixture of the two has an activity somewhat greater than that of pure aluminum chloride.