Thirty diarylacrylonitriles, carrying various para substituents in the phenyl ring attached to the position 1 of the ethylenic bridge and various heterorings (thienyl, furyl, pyrryl, N-methylpyrryl) attached to the position 2, have been investigated on silica gel. An additional substituent is present in the thienyl derivatives. The capacity factors of all the compounds can be grouped in only five or six families, according to the variation in the para-phenyl substitution or in the heteroring moiety, respectively. The strongest effect in the enhancement of the capacity factors is given by a methoxy or nitro group in the para-phenyl position