Studies in Trifluoromethanessulfonic Acid. 2. Kinetics and Mechanism of Isomerization of Xylenes

Article abstract of DOI:10.1021/jo00142a010

The rates of isomerization of o- and p-xylenes to m-xylene have been measured in the solvent trifluoromethanesulfonic acid (triflic acid, CF3SO3H), using NMR, GLC, and conductimetric methods.At low concentration (<0.02 M) the expected first-order kinetics were observed, whereas at higher concentrations the reactions followed apparent second-order kinetics.The mechanism of the reaction is discussed in terms of intimate ion pairing and possible incursion of donor-acceptor complexes between protonated and unprotonated solute molecules.