Sulfonyl Chloride Kinetics. Part III. Nucleophilic Interaction on the Transition State for 4-X-Benzenesulfonyl Chloride Solvolyses

Abstract

The kinetic solvent isotope effect [Formula: see text], was measured for 4-X-benzenesulfonyl chlorides (where X = MeO, Me, H, Br, and NO2) and shown to vary systematically, giving linear correlations with Hammett σ values and with [Formula: see text] ratios. These results contrast with the lack of sensitivity in k.s.i.e. to structural changes for displacement from a saturated carbon atom. This behavior is attributed to a greater degree of bond making required to achieve a critical charge on the chloride of the sulfonyl chloride at the transition state.