Friedel-CraFts Alkylation Reaction Catalysts and Complexes

Hydride Transfer and the Molecular weight Distribution of Polypropylene

“…Applying the Stirling approximation to the factorials in the form n\ = nne~n\/2rn, and letting N -* <», c -* ooj and N/c = s, (the olefin-to-catalyst ratio) the resulting distribution function becomes Pn en~' Zs\ VO™ w (14) For a continuous polymerization stage (CFSTR), the distribution may be obtained from equation 14 by multiplying by e~a/s'/s' and integrating over s, where s' is the olefin-to-catalyst mole ratio. The result is P"' = s' + 1)"+1 (15) If the continuous stage is followed by a batch stage (semi-continuous method) the final distribution is where A = t(s + l)/s, t is the ratio of olefin-to-catalyst in the batch stage and s is the ratio of olefin to catalyst in the continuous stage.…”

Friedel-Crafts Reactions

“…Eley and King ( 41) have assigned the formula, CeHeAlBrs, to the solid complex which they obtained, having an incongruent melting point of 37°C. The investigations of Brown and coworkers (20,23) indicate that this is not necessarily the case. In fact, their results establish that aluminum bromide exists in aromatic hydrocarbon complexes in dimeric form and there is a weak interaction between the electrons of the aromatic system and the ALBr,, which can be formulated This complex is similar to those which they also established for the alkyl homologs of benzene.…”

“…In a biennial review of this type, it is difficult to give proper emphasis to the importance of these contributions without reviewing the literature of the prior art. Several excellent theoretical review articles of the Friedel-Crafts reaction have been published (23,28,44)• The paper by Brown and coworkers (23) on reaction of alkyl halides with aromatic nuclei is particularly noteworthy since it contains important data hitherto unpublished.…”

Rearrangement in Alkyl Groups during Substitution Reactions

“…A carbonium-ion mechanism will also explain the results, although there is considerable evidence which points to the operation of a con- certed bimolecular process (154). Brown considers the alkylation to be bimolecular for primary halides and to involve reaction of benzene with the undissociated alkyl halide-aluminum halide complex (15).…”