The nature of the transition state in ester pyrolysis. Part III. The Hammett correlation for pyrolysis of t-butyl benzoates

Abstract

Rates of pyrolysis of t-butyl benzoates have been measured at 584.9 and 570.8 K. The data give a good correlation with σ° values with p +0.58 (corrected to 600 K). The magnitude of this value compared to previously determined values (corrected to 600 K) for ethyl and isopropyl benzoates of 0.26 and 0.335 respectively confirms that the transition state polarity for pyrolysis of esters increases along the series primary < secondary < tertiary with the biggest polarity difference occurring between the secondary and tertiary esters.