THE APPLICATION OF THE HAMMETT EQUATION TO ORTHO-SUBSTITUTED BENZENE REACTION SERIES

Abstract

The Hammett equation is directly applicable to ortho-substituted benzene reaction series in which reaction site and benzene ring are separated by some group Z, apparently due to the absence of steric effects in these series. The σp values are used in the correlations. Fourteen ortho-substituted benzene reaction series have been correlated. The electrical effect of a substituent in the ortho position is found to be about 0.75 times its effect in the para position. The effect of the side-chain Z in the transmission of substituent effects is OCH2 > SCH2 > CH = CH > SeCH2 > CH2CH2.