Investigation into the use of graphite-aluminium trichloride as a Friedel-Crafts' catalyst

Abstract

The project described in this thesis had a dual purpose. The first was to study the catalytic application of graphite-AlCl3 intercalation compound in Friedel-Crafts' reactions. The second was an experimental investigation into the extraction phenomena of graphite-AlCl3 - with a view of elucidating certain fundamental aspects of the mechanism involved. Limitations were placed upon the scope of the study when a Canadian team [36] published their report in this field after the present work had started. However consideration was given to emphasize aspects not covered by them. To this end, various operational techniques were employed, particular attention being paid to G.L.C., X.R.D. And U.V. absorption spectroscopy and where possible, mass spectroscopy. The graphite-AlCl3 intercalation compound was found to be a milder catalyst than AlCl3 in many Friedel-Crafts' alkylations and some evidence is presented for substantial variations in the isomeric distribution and degree of substitution in the products. Where appropriate, the chemical physics of the catalyst was dealt with to elucidate the mechanism involved. A short theoretical treatment of the activation energy for the diffusion of A1C13 from intercalation is also presented and discussed in the light of experimental observation. The interesting conclusion reached from these studies is that, at the present, graphite-AlCl3 intercalation compounds offer valuable applications and new possibilities in Friedel-Crafts' reactions.