BROMINE ADDITION TO OLEFINS IN AQUEOUS SOLUTION

Rates of addition of bromine to methyl acrylate, methyl crotonate, methyl methacrylate, and acrylamide in aqueous solutions have been measured electrometrically in the presence of added bromide at 20, 30, and 40°. The rate constants for addition of Br2 as well as of Br3- have been calculated and hence the corresponding values of activation energy and entropy of activation have been computed for each reaction. The relative reactivities of the four olefins follow the same order (methacrylate > crotonate > acrylamide > acrylate) with respect to both bromine and tribromide ion. For reaction with bromine, activation energy as well as frequency factor lies in the order acrylate > crotonate > acrylamide > methacrylate. For tribromide ion, activation energy lies in the order acrylamide > methacrylate > acrylate > crotonate, the sequence for the frequency factor being acrylamide > methacrylate > crotonate > acrylate. The results are not strictly in conformity with what should be expected from structural considerations. © 1969, American Chemical Society. All rights reserved.