Relation of Halogen Position to Physiological Properties in the Mono-, Di-, and Trichlorophenoxyacetic Acids

Abstract

The variation in biol. reaction with concn. of the 15 mono-, di-, and trichlorophenoxyacetic acids when applied (a) to roots of Lupinus albus and (b) to intact tomato plants was studied, and the most efficient compounds were found to have a common structural factor, viz., the presence of 2 unsubstituted positions in the benzene ring opposite one another. The probability that this is related to quinonoid reactions in the metabolism of the plant is discussed. 27 new compounds are described.