Water cocatalysis in the polymerization of benzene by ferric chloride

Abstract

Abstract The influence of change in water cocatalyst concentration on polymer yield and composition, and on reaction rate was investigated in the benzene‐ferric chloride system. For short reaction times, polymer yield passes through a maximum at a H 2 O/FeCl 3 molar ratio of 1. The most rapid rate of hydrogen chloride evolution was observed at this same ratio. The data suggest that ferric chloride monohydrate constitutes the active catalyst‐cocatalyst complex. With more prolonged reaction times, the yield maximum shifted to lower values of H 2 O/FeCl 3 , accompanied by a progressive increase in polymer yield. As evidenced by the C/(H + Cl) atomic ratio, p ‐polyphenyl formation is favored by short reaction times at H 2 O/FeCl 3 ratios of 0, 1, and 2. Longer reaction times, gave C/(H + Cl) ratios greater than 1.5 for the polymer, indicating the presence of polynuclear structures. An increase in chlorine content attended the rise in C/(H + Cl) ratio. Interpretations of the data are presented.