Determination and interpretation of second order rate constants for the addition of hydrogen halides to alkenes

摘要

An extensive range of second order rate constants for the addition of hydrogen halides to alkenes in 98% v/v ethanoicnacid (acetic acid)–water have been obtained by conductivity measurements. The rate constants are in the expectednorder of HF < HCl < HBr < HI. The rates with different alkenes cannot be rationalised solely by a consideration ofncarbocation stability and it has been necessary to consider steric effects in order to explain the observed order.