A cryoscopic study of the association of phenolic compounds in benzene

The cryoscopic behavior of phenol, positional isomers of chlorophenol and cresol, and 2,5-, 2,6-, 3,4-, and 3,5-dimethyl phenol were studied in benzene, and equilibrium constants describing this behavior in terms of association were determined for the concentration range 0-0.8 m. The results indicate that substitution of a ring hydrogen of phenol by either chlorine or methyl decreases the amount of association of the parent phenol, chloro isomers having less association than methyl isomers. The degree of association is qualitatively related to the effects of the substituents on the π electron cloud of the phenyl ring.