Backbone-assisted reactions of polymers. VII. Kinetics of isomerization of poly[(chloromethyl)thiirane] in the absence of solvent

The kinetics of the repeating unit isomerization of poly[(chloromethyl)thiirane] have been determined at four temperatures in the absence of solvent. The reaction can be treated as a reversible first-order process with rate constants and activation energies similar to those observed in analogous reactions of β-chlorosulfides of low molecular weight. These observations are consistent with a mechanistic scheme that involves rate determining cyclization to a thiiranium ion intermediate, followed by rapid ring opening by chloride ion attack.